Integrated busbar, battery module and battery pack

Abstract

The utility model discloses an integrated busbar, a battery module and a battery pack, and belongs to the technical field of batteries, the integrated busbar comprises a substrate and a busbar arranged on the substrate; a tab via hole penetrating through the thickness of the substrate is formed in the substrate, and the tab via hole is arranged adjacent to the busbar; at least part of the busbar is thinned to form a limiting groove. The battery module comprises a battery cell and an integrated busbar, wherein the battery cell comprises a battery cell body and a tab arranged on the battery cell body; the tabs penetrate through the tab via holes and then are bent towards the busbar to form bent parts, at least part of the bent parts are located in the corresponding limiting grooves, and first gaps are formed between the side walls of the limiting grooves and the side walls of the bent parts and serve as to-be-welded areas. The battery pack comprises the battery module. In the welding process, the welding pressing head abuts against the to-be-welded area, due to the fact that the welding temperature is high, part of the busbar is melted into liquid and flows towards the periphery to fill the first gap, the cold joint risk is reduced, the burst point occurrence probability is reduced, and the welding quality is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to an integrated busbar, a battery module and a battery pack. Background Art

[0002] In existing battery modules, series / parallel connections between cells typically utilize 90° bent tabs that are bonded to the busbars and secured by laser welding. Penetration welding is a common method, where the welding head presses against the surface of the tab to weld a single-layer tab to the busbar, or a stacked double-layer tab to the busbar.

[0003] Because battery cell heights vary and cannot be guaranteed to be completely consistent when stacked, the size of the overlapping tabs in series after the tabs are bent is difficult to control, and the tabs can easily become too long or too short. If they are too long, the bent root of the upper tab will interfere with the lower tab. If they are too short, the overlapping tabs in series will be too narrow, and the welding head will not be able to press the edge of the lower tab, which is equivalent to a gap under the upper tab, resulting in a hot spot during welding.

[0004] Furthermore, even when the dimensions of the overlapping tabs in series are carefully controlled, gaps between the tabs and the busbars can occur, leading to hot spots during welding. These hot spots can cause cold solder joints or insufficient flow area, easily leading to short circuits between cells and making it difficult to meet quality requirements. Utility Model Content

[0005] The purpose of the present invention is to provide an integrated busbar, a battery module and a battery pack to solve the technical problems in the prior art of welding the tabs and busbars of the battery cells, which are prone to cold welding or insufficient flow area.

[0006] As conceived above, the technical solution adopted by the utility model is:

[0007] An integrated busbar, comprising a substrate and a busbar arranged on the substrate;

[0008] Wherein, the substrate is provided with a tab via hole penetrating the thickness of the substrate, and the tab via hole is arranged adjacent to the busbar;

[0009] At least a portion of the busbar is thinned to form a limiting groove.

[0010] Preferably, the projection of the side wall of the limiting groove on the bottom wall of the limiting groove is in a straight line, an arc, a sawtooth or a wave shape;

[0011] Alternatively, the projection of the side wall of the limiting groove on the bottom wall of the limiting groove is at least partially linear and at least partially curved.

[0012] Preferably, a boss is provided on the bottom wall of the limiting groove.

[0013] Preferably, the projection of the outer peripheral wall of the boss on the bottom wall of the limiting groove is circular, elliptical or polygonal;

[0014] Alternatively, the projection of the outer peripheral wall of the boss on the bottom wall of the limiting groove is at least partially linear and at least partially curved.

[0015] A battery module, comprising:

[0016] A battery cell, comprising a battery cell body and a tab disposed on the battery cell body;

[0017] An integrated busbar, comprising a substrate and a busbar disposed on the substrate;

[0018] The substrate is provided with a tab through-hole penetrating the thickness of the substrate, and the tab through-hole is arranged adjacent to the busbar, so that the tab is bent toward the busbar to form a bent portion after passing through the tab through-hole;

[0019] At least part of the busbar is thinned to form a limiting groove, at least part of the bent portion is located in the corresponding limiting groove, and a first gap is formed between the side wall of the limiting groove and the side wall of the bent portion as a welding area.

[0020] Preferably, the first slits are in a straight line, an arc line, a sawtooth shape or a wavy shape; or, at least part of the first slits are in a straight line and at least part of the first slits are in a curved shape.

[0021] Preferably, the side wall of the limiting groove is provided with a first splicing part, and the side wall of the bending part is provided with a corresponding second splicing part, the second splicing part and the first splicing part are connected to each other, and the first gap is located between the second splicing part and the first splicing part.

[0022] Preferably, the bending portion is provided with an avoidance hole penetrating the thickness of the bending portion, a boss is provided in the limiting groove, the bending portion is located in the limiting groove so that the boss is correspondingly plugged into the avoidance hole, and a second gap is formed between the outer peripheral wall of the boss and the inner peripheral wall of the avoidance hole as an area to be welded.

[0023] Preferably, the second slits are circular, elliptical or polygonal; or, at least part of the second slits are linear and at least part of the second slits are curved.

[0024] A battery pack comprises a box and the battery module as described above, wherein the battery module is arranged in the box.

[0025] Beneficial effects of the utility model:

[0026] The integrated busbar proposed in this utility model comprises a base plate and a busbar. The base plate is provided with tab vias that penetrate the thickness of the base plate, and the tab vias are arranged adjacent to the busbar. At least a portion of the busbar is thinned to form a limiting groove. During use, the limiting groove can cooperate with the tab, facilitating the welding pressure head to abut the area between the limiting groove and the tab. Due to the high welding temperature, part of the busbar melts into liquid and flows to the surrounding area, effectively reducing the risk of cold solder joints and the probability of hot spots.

[0027] The battery module proposed by the present invention is provided with a tab through-hole which penetrates the thickness of the substrate on the substrate, and at least part of the thickness of the bus is thinned to form a limiting groove. After the tab passes through the tab through-hole, it is bent toward the bus to form a bent portion, and at least part of the bent portion is located in the corresponding limiting groove. A first gap is formed between the side wall of the limiting groove and the side wall of the bent portion as the area to be welded. During welding, the welding pressure head abuts against the area to be welded. Due to the high welding temperature, part of the bus melts into liquid and flows to the periphery to fill the first gap, which is equivalent to changing the traditional penetration welding to butt welding, effectively reducing the risk of cold welding, reducing the probability of explosion points, and improving the welding quality of the tab and the bus. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic structural diagram of a battery module provided by an embodiment of the present utility model;

[0029] Figure 2 This is a partial structural diagram of a battery module provided by an embodiment of the present utility model;

[0030] Figure 3 This is a schematic diagram of the structure of the battery cell provided by an embodiment of the present utility model;

[0031] Figure 4 This is a schematic diagram of the partial structure of a battery cell provided by an embodiment of the present utility model;

[0032] Figure 5 This is a schematic structural diagram of an integrated busbar provided by an embodiment of the present utility model;

[0033] Figure 6 This is a schematic structural diagram of the first busbar provided by an embodiment of the present utility model;

[0034] Figure 7 This is a schematic structural diagram of a second busbar provided by an embodiment of the present utility model;

[0035] Figure 8 This is a schematic structural diagram of a third type of busbar provided by an embodiment of the present utility model;

[0036] Figure 9 This is a schematic structural diagram of the fourth bus provided by an embodiment of the present utility model.

[0037] In the picture:

[0038] 10. Battery cell; 101. First gap; 102. Second gap; 11. Battery cell body; 12. Tab; 121. Bend portion; 122. Avoidance hole; 123. Second splicing portion;

[0039] 20. Integrated busbar; 21. Base plate; 211. Tab via; 22. Busbar; 221. Limiting groove; 222. Boss; 223. First joint. DETAILED DESCRIPTION

[0040] The following describes in detail embodiments of the present invention. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0041] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0042] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0043] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0044] See also Figures 1 to 5The utility model provides a battery module, including a battery cell 10 and an integrated busbar 20. The battery cell 10 includes a battery cell body 11 and a tab 12 provided on the battery cell body 11; the integrated busbar 20 includes a substrate 21 and a busbar 22 provided on the substrate 21. The substrate 21 is provided with a tab through-hole 211 that penetrates the thickness of the substrate 21, and the tab through-hole 211 is provided adjacent to the busbar 22, so that the tab 12 can bend toward the busbar 22 to form a bent portion 121 after passing through the tab through-hole 211. At least part of the thickness of the busbar 22 is thinned to form a limiting groove 221, and at least part of the bent portion 121 is located in the corresponding limiting groove 221. A first gap 101 is formed between the side wall of the limiting groove 221 and the side wall of the bent portion 121 as a welding area.

[0045] When welding the tab 12 and the bus 22, the welding head abuts against the area to be welded. Due to the high welding temperature, part of the bus 22 melts into liquid and flows to the surrounding area to fill the first gap 101, which is equivalent to changing the traditional penetration welding to butt welding, effectively reducing the risk of cold welding, reducing the probability of explosion points, and improving the welding quality of the tab 12 and the bus 22.

[0046] In order to facilitate melting of the busbar 22 at high temperature, the busbar 22 can be made of materials such as aluminum and aluminum alloy.

[0047] Among them, the integrated busbar 20 includes a substrate 21 and a busbar 22 arranged on the substrate 21. By setting a limiting groove 221 on the busbar 22, the limiting groove 221 can accommodate the pole ear 12, which is convenient for the welding pressure head to abut against the area between the limiting groove 221 and the pole ear 12. Due to the high welding temperature, part of the busbar 22 melts into liquid and flows to the surrounding area, effectively reducing the risk of cold welding and reducing the probability of explosion points.

[0048] In this embodiment, the battery module includes a plurality of battery cells 10, and the plurality of battery cells 10 are stacked in sequence along a first direction. Figure 1 The bus 22 extends along the second direction on the substrate 21, the second direction is the length direction of the bus 22, as shown in FIG. Figure 1 The Y direction shown in FIG; the tab 12 passes through the tab via 211 along the third direction, the third direction as shown Figure 1 The Z direction is shown.

[0049] The limiting groove 221 has vertically arranged side walls and a bottom wall, which enclose an accommodating space. After the tab 12 passes through the tab through-hole 211, it bends toward the busbar 22 to form a bent portion 121. The bent portion 121 is located within the limiting groove 221, that is, within the accommodating space. The limiting groove 221 can pass through the busbar 22 along the X-direction, that is, the side walls are distributed on both sides of the bottom wall, or the side walls are distributed on three sides of the bottom wall, and the bent portion 121 can only be inserted into the limiting groove 221 from one side of the limiting groove 221.

[0050] Typically, a battery cell 10 includes two tabs 12, one for the positive electrode and one for the negative electrode. The battery cells 10 can be connected in parallel or in series. A single bend 121 is provided within a retaining groove 221; alternatively, at least two bends 121 are provided within the same retaining groove 221, with the bends 121 stacked one on top of the other.

[0051] For example, Figure 2 As shown, when one bending portion 121 is provided in a limiting groove 221, the tab via 211 is provided on one side of the bottom wall along the X direction, and the side walls are distributed on both sides of the bottom wall along the Y direction. When two bending portions 121 are provided in the same limiting groove 221, the two tab vias 211 are distributed on both sides of the busbar 22 along the X direction, and the side walls are distributed on both sides of the bottom wall along the Y direction.

[0052] When two bending portions 121 are provided in a limiting groove 221, the depth of the limiting groove 221 is not less than the thickness of the two bending portions 121, so that the two bending portions 121 are not higher than the limiting groove 221 after being stacked. During welding, both bending portions 121 can be taken into account to ensure welding quality.

[0053] Because the sidewalls and bottom wall of the limiting groove 221 are perpendicular, the projection of the sidewalls of the limiting groove 221 onto the bottom wall of the limiting groove 221 is linear. The specific shape can be set according to actual needs. Optionally, the projection of the sidewalls of the limiting groove 221 onto the bottom wall of the limiting groove 221 is linear, curved, zigzag, or wavy; or, the projection of the sidewalls of the limiting groove 221 onto the bottom wall of the limiting groove 221 is at least partially linear and at least partially curved.

[0054] For example, see Figures 6 to 8 The projection of the side wall of the limiting groove 221 on the bottom wall of the limiting groove 221 is sawtooth-shaped. Figure 9 The projection of the side wall of the limiting groove 221 on the bottom wall of the limiting groove 221 is wavy.

[0055] After at least part of the bent portion 121 of the tab 12 is positioned within the corresponding limiting groove 221, a first gap 101 is formed between the sidewalls of the limiting groove 221 and the sidewalls of the bent portion 121 as a welding area. The provision of the first gap 101 facilitates melting and filling of the busbar 22, thereby improving welding quality.

[0056] The first gap 101 is in a straight line, an arc, a zigzag or a wavy shape; or, at least part of the first gap 101 is in a straight line and at least part of the first gap 101 is in a curved shape. In one embodiment, the side wall of the limiting groove 221 is a plane, the corresponding side wall of the pole ear 12 is set to a plane, and the corresponding first gap 101 is in a straight line or a broken line shape. In one embodiment, the side wall of the limiting groove 221 is an arc surface, the corresponding side wall of the pole ear 12 is set to an arc surface, and the corresponding first gap 101 is in an arc shape. In one embodiment, the side wall of the limiting groove 221 is a serrated surface, such as Figures 6 to 8 As shown, the side wall of the corresponding tab 12 is set to a serrated surface, and the corresponding first gap 101 is serrated. In one embodiment, the side wall of the limiting groove 221 is a wave surface, such as Figure 9 As shown, the side wall of the corresponding tab 12 is configured as a wavy surface, and the corresponding first gap 101 is wavy.

[0057] The sidewall of the limiting groove 221 is provided with a first splicing portion 223, and the sidewall of the bent portion 121 is provided with a corresponding second splicing portion 123. The second splicing portion 123 and the first splicing portion 223 are connected to each other, and the first gap 101 is located between the second splicing portion 123 and the first splicing portion 223. By providing the second splicing portion 123 and the first splicing portion 223, the extension length of the first gap 101 is increased, thereby increasing the contact area between the tab 12 and the busbar 22, thereby improving the welding quality.

[0058] The first splicing portion 223 may be a groove, and the second splicing portion 123 may be a protrusion, and the groove and the protrusion are connected to each other. The shape of the first splicing portion 223 can be set according to actual needs and is not limited to the shapes listed in this embodiment. For example, the second splicing portion 123 and the first splicing portion 223 are sawtooth-shaped, such as Figures 6 to 8 As shown, the corresponding first gap 101 is zigzag-shaped. For example, the second splicing portion 123 and the first splicing portion 223 are arc-shaped, as shown in FIG. Figure 9 As shown, the corresponding first gap 101 is wavy.

[0059] A boss 222 is provided on the bottom wall of the retaining groove 221. The boss 222 is capable of engaging with the bent portion 121 of the tab 12 to increase the contact area. Alternatively, the bent portion 121 may be provided with a relief hole 122 that penetrates the thickness of the bent portion 121. The bent portion 121 is positioned within the retaining groove 221 so that the boss 222 and the relief hole 122 engage with each other. A second gap 102 is formed between the outer wall of the boss 222 and the inner wall of the relief hole 122, serving as the welding area.

[0060] When welding the tab 12 and the busbar 22, the welding head contacts the area to be welded. Due to the high welding temperature, part of the busbar 22 melts into liquid and flows to the surrounding area to fill the second gap 102. This is equivalent to changing the traditional penetration welding to butt welding, effectively reducing the risk of cold welding and the probability of explosion points, and improving the welding quality of the tab 12 and the busbar 22. During welding, the first gap 101 and the second gap 102 can be welded simultaneously or sequentially.

[0061] The number of bosses 222 provided in a limiting groove may be one or at least two. When at least two bosses 222 are provided in a limiting groove 221, adjacent bosses 222 are spaced apart from each other. The shape of the boss 222 can be set according to actual needs and is not limited to the shapes listed in this embodiment. The outer peripheral wall of the boss 222 is perpendicular to the bottom wall of the limiting groove 221, and the projection of the outer peripheral wall of the boss 222 on the bottom wall of the limiting groove 221 is linear. For example, the projection of the outer peripheral wall of the boss 222 on the bottom wall of the limiting groove 221 is circular, elliptical or polygonal; or, the projection of the outer peripheral wall of the boss 222 on the bottom wall of the limiting groove 221 is at least partially linear and at least partially curved.

[0062] In one embodiment, the boss 222 is in the shape of an elliptical column, such as Figure 6 and Figure 9 As shown, the projection of the outer peripheral wall of the corresponding boss 222 on the bottom wall of the limiting groove 221 is elliptical. In one embodiment, the boss 222 is semi-elliptical, such as Figure 7 As shown, the projection of the outer peripheral wall of the corresponding boss 222 on the bottom wall of the limiting groove 221 is semi-elliptical, that is, the projection of the outer peripheral wall of the boss 222 on the bottom wall of the limiting groove 221 is partially linear and partially curved. In one embodiment, the boss 222 is in the shape of a quadrangular prism, such as Figure 8 As shown, the projection of the outer peripheral wall of the corresponding boss 222 on the bottom wall of the limiting groove 221 is a quadrilateral, which can be a rhombus.

[0063] The second slits 102 are circular, elliptical or polygonal; or at least part of the second slits 102 are linear and at least part of the second slits 102 are curved, thereby increasing the contact area between the busbar 22 and the tab 12 and improving the welding quality.

[0064] In one embodiment, the outer peripheral wall of the boss 222 extends along a circle, the corresponding avoidance hole 122 is a circular hole, and the corresponding second gap 102 is circular. In one embodiment, the outer peripheral wall of the boss 222 extends along an ellipse, such as Figure 6 and Figure 9 As shown, the corresponding avoidance hole 122 is an elliptical hole, and the corresponding second gap 102 is elliptical. In one embodiment, the outer peripheral wall of the boss 222 extends along a semi-elliptical shape, as shown in FIG. Figure 7 As shown, the corresponding avoidance hole 122 is a semi-elliptical hole, and the corresponding second gap 102 is semi-elliptical. In one embodiment, the outer peripheral wall of the boss 222 extends along a diamond shape, such as Figure 8 As shown, the corresponding avoidance hole 122 is a diamond-shaped hole, and the corresponding second gap 102 is a diamond-shaped hole.

[0065] An embodiment of the present invention further provides a battery pack, comprising a box and the above-mentioned battery module, wherein the battery module is disposed in the box.

[0066] The above embodiments merely illustrate the basic principles and features of the present invention. The present invention is not limited to the above embodiments. Various changes and modifications are possible without departing from the spirit and scope of the present invention. Such changes and modifications are within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. An integrated busbar, characterized in that: The integrated busbar comprises a substrate (21) and a busbar (22) arranged on the substrate (21); Wherein, the substrate (21) is provided with a tab via (211) penetrating the thickness of the substrate (21), and the tab via (211) is arranged adjacent to the busbar (22); At least a portion of the busbar (22) is thinned to form a limiting groove (221).

2. The integrated busbar according to claim 1, characterized in that: The projection of the side wall of the limiting groove (221) on the bottom wall of the limiting groove (221) is in a straight line, an arc, a sawtooth or a wave shape; Alternatively, the projection of the side wall of the limiting groove (221) on the bottom wall of the limiting groove (221) is at least partially linear and at least partially curved.

3. The integrated busbar according to claim 1, characterized in that: A boss (222) is provided on the bottom wall of the limiting groove (221).

4. The integrated busbar according to claim 3, characterized in that: The projection of the outer peripheral wall of the boss (222) on the bottom wall of the limiting groove (221) is circular, elliptical or polygonal; Alternatively, the projection of the outer peripheral wall of the boss (222) on the bottom wall of the limiting groove (221) is at least partially linear and at least partially curved.

5. A battery module, characterized in that: include: A battery cell (10), the battery cell (10) comprising a battery cell body (11) and a tab (12) disposed on the battery cell body (11); An integrated busbar (20), the integrated busbar (20) comprising a substrate (21) and a busbar (22) disposed on the substrate (21); The substrate (21) is provided with a tab through-hole (211) penetrating the thickness of the substrate (21), and the tab through-hole (211) is arranged adjacent to the busbar (22), so that the tab (12) is bent toward the busbar (22) to form a bent portion (121) after passing through the tab through-hole (211); At least part of the thickness of the busbar (22) is thinned to form a limiting groove (221), at least part of the bent portion (121) is located in the corresponding limiting groove (221), and a first gap (101) is formed between the side wall of the limiting groove (221) and the side wall of the bent portion (121) as a welding area.

6. The battery module according to claim 5, characterized in that: The first slit (101) is in a straight line, an arc line, a sawtooth shape or a wavy shape; or, at least part of the first slit (101) is in a straight line shape and at least part of the first slit (101) is in a curved shape.

7. The battery module according to claim 5, characterized in that: The side wall of the limiting groove (221) is provided with a first splicing portion (223), and the side wall of the bending portion (121) is provided with a corresponding second splicing portion (123), the second splicing portion (123) and the first splicing portion (223) are butted against each other, and the first gap (101) is located between the second splicing portion (123) and the first splicing portion (223).

8. The battery module according to claim 5, characterized in that: The bending portion (121) is provided with an avoidance hole (122) penetrating the thickness of the bending portion (121); a boss (222) is provided in the limiting groove (221); the bending portion (121) is located in the limiting groove (221) so that the boss (222) and the avoidance hole (122) are correspondingly plugged in; a second gap (102) is formed between the outer peripheral wall of the boss (222) and the inner peripheral wall of the avoidance hole (122) as a welding area.

9. The battery module according to claim 8, characterized in that: The second slit (102) is circular, elliptical or polygonal; or at least part of the second slit (102) is linear and at least part of the second slit (102) is curved.

10. A battery pack, characterized in that: It comprises a box body and the battery module according to any one of claims 5 to 9, wherein the battery module is arranged in the box body.

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