A large-capacity battery current collecting column structure

Abstract

This application discloses a current collector column structure for large-capacity batteries, comprising current collector columns positioned on either side of a parallel cell group. The columns comprise a rectangular cross-section and connectors positioned on one or both sides of the column, connecting to the current collectors on either side of the cell group. The connectors are thinner than the column and are provided with multiple through-grooves. This application can address the difficulty of welding thicker current collectors to the current collectors.

Description

Technical Field

[0001] The present application relates to the technical field of lithium batteries, and in particular to a current collecting column structure for large-capacity batteries. Background Art

[0002] Large-capacity lithium batteries are one of the development trends for lithium batteries, and they can be used in energy storage and power battery applications. Compared to small-capacity batteries, large-capacity batteries eliminate the need for a control device for each cell or battery pack. While the cost of a single cell is higher, the number of associated supporting equipment is significantly reduced, ultimately reducing costs and facilitating market competition.

[0003] Since the cells inside the large-capacity battery are connected in parallel, the current transmitted from the inside to the outside is very large. For a 3000Ah large-capacity single cell, its output current must reach 3000A. The cross-sectional area of ​​the current collecting column of such a large-capacity battery must be very large. Such a large cross-sectional area brings great difficulties to the welding of the current collecting sheet and the current collecting column.

[0004] Currently, ultrasonic welding or laser welding is generally used to weld battery cells and current collectors. Laser welding can weld metals with greater thickness than ultrasonic welding, but the current thickness of laser welding is generally less than 4mm. The current collector column thickness of large-capacity batteries generally needs to be at least 10mm. When welding current collector columns of this thickness to the current collector on the battery cell, laser welding is generally used. Due to the limitations of the laser head, laser welding must consider the thickness of the material, the direction of welding, and the welding sequence. Compared with current small-capacity batteries, the welding difficulty is much greater.

[0005] Patent CN212257553U discloses a battery structure comprising a top cover and a battery cell. The top cover is provided with downwardly extending current collectors on both sides, and the battery cell is provided with tabs on both sides. The tabs are folded toward the current collectors to form a folded portion, and the current collectors are connected to the battery cell via the tabs. Although the connection between the current collectors and the battery cell is convenient, it occupies a large space, and too few battery cells can be installed within the limited space.

[0006] Patent CN111384349A discloses a current collector and a secondary battery, comprising: a first sheet; a second sheet intersecting the first sheet, the second sheet being used to electrically connect to the electrode column; a current collecting unit, wherein the current collecting unit and the second sheet are respectively arranged on opposite sides of the first sheet along a first thickness direction, the first thickness direction intersecting the second thickness direction of the second sheet; the current collecting unit comprising a first collecting piece, the first collecting piece being used to electrically connect to the electrode tab, and the first collecting piece having a first connecting end connected to the first sheet, the first connecting end extending along a first direction perpendicular to the first and second thickness directions. However, once the capacity of the battery increases, the thickness of the current collecting column becomes thicker, which not only increases the length of the battery cell connector, but also wastes more material, making it uneconomical to divide the smaller current. Summary of the Invention

[0007] In order to solve the above-mentioned technical problem of difficulty in welding large-capacity batteries, the technical solution adopted by the present invention is as follows:

[0008] An embodiment of the present invention provides a large-capacity battery current collector column structure, including current collector columns located on both sides of a parallel battery cell group. The current collector column includes a column with a rectangular cross-section and a connector arranged on one side or both sides of the column. The connector is connected to the current collectors on both sides of the battery cell group; the thickness of the connector is less than the thickness of the column; and a plurality of through grooves are provided on the connector.

[0009] Furthermore, in an embodiment provided herein, the through-slot on the connector is a rectangular through-slot, which may have rounded corners. The through-slot may be open or closed. The thickness of the connector is less than or equal to four millimeters. A secondary connector is provided on the current collector, extending through the through-slot and vertically bent, and then welded to the connector.

[0010] Furthermore, in the embodiments provided herein, the current collecting column is a one-piece structure or a split structure. When the current collecting column is a split structure, the connector is L-shaped; one side of the L-shaped connector with a through slot is connected to the current collector, and the other side is connected to the column. The negative electrode connector is made of a copper-aluminum composite material, and the positive electrode connector is an aluminum plate; the aluminum surface of the copper-aluminum composite plate is welded to the column, and the copper surface is welded to the current collector.

[0011] Furthermore, in the embodiment provided by the present invention, at least one heat-scaling tube is provided along the length of the current collecting column for equalizing or conducting heat to the current collecting column. The current collecting column is provided with a semiconductor cooling plate for cooling or heating the current collecting column.

[0012] The current collecting column structure of a large-capacity battery provided by the present invention has the following advantages:

[0013] 1. Since the laser heads of laser welding equipment all weld from top to bottom, one design scheme of the present invention is to design the current collecting column and the connecting piece as an integrated whole, and to provide a plurality of through slots on the connecting piece, so that the secondary connecting pieces on the multiple current collectors at the bottom of the battery cell group can pass through the through slots to the upper surface of the current collecting column, thereby facilitating the welding of the battery cell current collector and the current collecting column and improving production efficiency.

[0014] 2. Another design of the present invention is to separate the current collector and the first connector, making the connector an L-shaped connector with multiple through-slots. This allows the secondary connectors of the multiple current collectors at the bottom of the cell pack to pass through the multiple through-slots to the top surface of the current collector, facilitating welding of the current collector to the current collecting column. Furthermore, the L-shaped connector is lighter, making welding more convenient and efficient.

[0015] 3. When welding the negative electrode of the parallel battery cells of large-capacity batteries with L-shaped connectors, copper-aluminum composite plates can be conveniently used, so that the copper negative electrode current collector of the battery cell can be more conveniently welded to the aluminum current collecting column.

[0016] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a schematic structural diagram of the current collecting column connection structure provided in an embodiment of the present application.

[0019] Figure 2 This is one of the schematic diagrams of the connection structure between the current collecting column and the L-shaped connecting piece provided in an embodiment of the present application.

[0020] Figure 3 This is the second schematic diagram of the connection structure between the current collecting column and the L-shaped connecting piece provided in an embodiment of the present application.

[0021] Figure 4 This is the third schematic diagram of the connection structure between the current collecting column and the L-shaped connecting piece provided in an embodiment of the present application.

[0022] Figure 5 This is one of the schematic diagrams of the integrally formed collecting column structure provided in an embodiment of the present application.

[0023] Figure 6 This is the second schematic diagram of the integrally formed collecting column structure provided in an embodiment of the present application.

[0024] Figure 7 This is one of the schematic diagrams of the L-shaped connector structure provided in an embodiment of the present application.

[0025] Figure 8 This is the second schematic diagram of the L-shaped connector structure provided in an embodiment of the present application.

[0026] Figure 9 A schematic diagram of the structure of the battery cell provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0028] It should be understood that terms such as “having,” “including,” and “comprising” used herein do not prescribe the existence or addition of one or more other elements or combinations thereof.

[0029] The terms "first" and "second" and the like in the description and claims of the embodiments of the present invention are used to distinguish different objects rather than to describe a specific order of the objects.

[0030] In the description of the embodiments of the present invention, unless otherwise specified, “a plurality of” means two or more.

[0031] The technical solution of the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figures 1 to 4 As shown, an embodiment of the present invention provides a large-capacity battery current collector structure, including current collectors 2 located on both sides of a parallel cell group 1, the current collector 2 including a column 21 with a rectangular cross-section, and a connector 22 arranged on one side or both sides of the column 21, the connector 22 being connected to the current collectors 11 on both sides of the cell group 1; the thickness of the connector 22 is less than the thickness of the column 21, and a plurality of through grooves 23 / 231 are provided on the connector 22.

[0033] Furthermore, the battery pack includes at least two battery cells 10 , and the stacking direction of the large-capacity battery cells 10 is parallel to the long side direction of the current collecting column 2 .

[0034] In the embodiments provided by the present invention, Figures 5 to 8 As shown, optionally, the through slot 23 / 231 on the connecting member 22 is a rectangular through slot, or an arc-rectangular through slot.

[0035] Furthermore, the through groove 23 / 231 is an open through groove or a closed through groove.

[0036] Furthermore, in the embodiment provided by the present invention, the thickness of the connecting member 22 is less than or equal to four millimeters, so as to facilitate laser welding connection between the connecting member 22 and the current collecting column body 21 .

[0037] In the embodiments provided by the present invention, Figure 9 As shown, optionally, a secondary connecting member 12 is provided on the current collector 11 , and the secondary connecting member 12 passes through the through groove 23 / 231 and is vertically bent and welded to the connecting member 22 .

[0038] In the embodiment provided by the present invention, the current collecting column is an integrated structure or a split structure.

[0039] Furthermore, if Figure 7 、 8 As shown, when the current collecting column is a split structure, the connecting member 22 is L-shaped; one side of the L-shaped connecting member 222 having a through groove 23 / 231 is connected to the current collector 12 , and the other side is connected to the column 21 .

[0040] Furthermore, the negative electrode connector is made of a copper-aluminum composite material, and the positive electrode connector is an aluminum plate; wherein the aluminum surface of the copper-aluminum composite plate is welded to the column, and the copper surface is welded to the current collector.

[0041] Furthermore, in an embodiment provided by the present invention, at least one heat-scaling tube is provided along the length direction of the current collecting column for performing heat equalization or heat conduction on the current collecting column.

[0042] Furthermore, in an embodiment provided by the present invention, a semiconductor refrigeration plate for cooling or heating the current collecting column is provided on the current collecting column. Example 1

[0043] like Figure 1 、 5 As shown, the present invention provides a current collecting column structure for a large-capacity battery. The current collecting column 2 is an integrated structure. The cross-section of the current collecting column body 21 is rectangular. A first connecting member 221 is provided on one side of the column body 21. The first connecting member 221 is provided with a plurality of open-shaped through grooves 23. The thickness of the current collecting column is 30 mm and the width is 70 mm. The thickness of the first connecting member is 5 mm. The current collectors on both sides of the battery cell are welded to the first connecting member. Example 2

[0044] On the basis of Example 1, a secondary connector 12 is provided on the current collector 11 . The secondary connector 12 directly passes through the through slot 23 and is vertically bent to be welded to the upper surface of the first connector 221 . Example 3

[0045] like Figure 1 、6 As shown, the present invention provides a current collecting column structure for a large-capacity battery. The current collecting column 2 is an integrated structure. The cross-section of the current collecting column body 21 is rectangular. First connecting members 221 are provided on both sides of the column body 21. The first connecting member 221 is provided with a plurality of open-shaped through grooves 23. The thickness of the current collecting column is 30 mm and the width is 80 mm. The thickness of the first connecting member is 6 mm. The current collectors on both sides of the battery cell are welded to the first connecting member. Example 4

[0046] On the basis of Example 3, a secondary connector 12 is provided on the current collector 11 . The secondary connector 12 directly passes through the through slot 23 and is vertically bent to be welded to the upper surface of the first connector 221 . Example 5

[0047] like Figure 2 、 3 As shown in Figures 4 and 7, the present invention provides a current collecting column structure for a large-capacity battery. The current collecting column 2 is a split structure, including a column 21 and a second connecting member 222. The cross section of the second connecting member 222 is L-shaped. A plurality of open through grooves 23 are provided on the L-shaped second connecting member 222. The thickness of the column is 30 mm, the width is 70 mm, and the thickness of the second connecting member is 2 mm. One side of the through groove 23 of the second connecting member 222 is welded to the current collectors 11 on both sides of the battery cell, and the other side is connected to the column 21. Example 6

[0048] On the basis of Example 5, a secondary connector 12 is provided on the current collector 11 . The secondary connector 12 directly passes through the through slot 23 and is vertically bent to be welded to the upper surface of the second connector 222 . Example 7

[0049] like Figure 2 、 3 As shown in Figures 4 and 8, the present invention provides a current collecting column structure for a large-capacity battery. The current collecting column 2 is a split structure, including a column 21 and a second connecting member 222. The cross section of the second connecting member 222 is L-shaped. A plurality of closed through grooves 231 are provided on the L-shaped second connecting member. The thickness of the column is 40 mm, the width is 80 mm, and the thickness of the second connecting member is 2 mm. One side of the through groove 231 of the second connecting member 222 is welded to the current collectors 11 on both sides of the battery cell, and the other side is connected to the column 21. Example 8

[0050] On the basis of Example 7, a secondary connecting member 11 is provided on the current collector 11 , and the secondary connecting member 12 directly passes through the through slot and is vertically bent, and is welded to the upper surface of the second connecting member.

[0051] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and exemplary embodiments. They can be applied to a variety of fields suitable for the present invention. Further modifications will be readily apparent to those skilled in the art. Therefore, the present invention is not limited to the specific details and illustrations shown and described herein without departing from the general concept defined by the claims and their equivalents.

Claims

1. A large-capacity battery current collecting column structure, comprising current collecting columns located on both sides of a parallel battery cell group, characterized in that: The battery cell group includes at least two battery cells, and the stacking direction of the battery cells is parallel to the long side direction of the current collecting column; the current collecting column includes a column with a rectangular cross section and a connector connected to one side or both sides of the column, and the connector is connected to the current collectors on both sides of the battery cell group; The thickness of the connecting member is less than the thickness of the column, and the thickness of the connecting member is less than or equal to four millimeters; The connecting piece is provided with a plurality of through slots; A secondary connector is provided on the current collector, the secondary connector passes through the through slot and is vertically bent, and is connected to the connector by laser welding; The column body and the connector of the same current collecting column are located on the same side of the parallel cell group.

2. A large-capacity battery current collecting column structure according to claim 1, characterized in that: The through slot on the connecting piece is a rectangular through slot, or a rectangular through slot with rounded corners.

3. A large-capacity battery current collecting column structure according to claim 2, characterized in that: The through groove is an open through groove or a closed through groove.

4. A large-capacity battery current collecting column structure according to claim 1, characterized in that: The current collecting column is an integrated structure or a split structure.

5. A large-capacity battery current collecting column structure as claimed in claim 4, characterized in that: When the current collecting column is a split structure, the connecting piece is L-shaped; The L-shaped connector has one side with a through groove connected to the current collector, and the other side is connected to the column.

6. A large-capacity battery current collecting column structure as claimed in claim 5, characterized in that: The negative electrode connector is made of copper-aluminum composite material, and the positive electrode connector is an aluminum plate; The aluminum surface of the copper-aluminum composite plate is connected to the column by welding, and the copper surface is connected to the current collector by welding.

7. A large-capacity battery current collecting column structure according to claim 1, characterized in that: At least one heat-scaling tube is provided along the length direction of the current collecting column for performing heat distribution or heat conduction on the current collecting column.

8. A large-capacity battery current collecting column structure according to claim 1 or 7, characterized in that: The current collecting column is provided with a semiconductor refrigeration plate for cooling or heating the current collecting column.

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