Busbar and battery module

Abstract

A busbar and a battery module, relating to the technical field of batteries. The busbar (001) comprises a busbar strip (012) and a plurality of current guide members (011) arranged at intervals. The current guide members (011) each comprise a fuse part (112) and a current guide part (111). The melting point of the fuse parts (112) is lower than those of the busbar strip (012) and the current guide parts (111). Two ends of each fuse part (112) are respectively connected to a current guide part (111) and the busbar strip (012). Each current guide part (111) is used for connecting to a positive electrode or negative electrode of a battery cell.

Description

Busbar and battery module

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on March 1, 2024, with application number 202420407843.2. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a bus and a battery module. Background Art

[0003] With the increasing application of power batteries, their safety issues are receiving increasing attention. Battery short circuits are a significant factor contributing to these safety issues. Currently, short-circuit protection is primarily addressed by designing a fuse structure on the busbar. In the event of a battery short circuit or temperature anomaly, the fuse melts, disconnecting the battery circuit.

[0004] Typically, there are multiple busbars, which connect multiple battery cells in series in sequence. That is, one side of the busbar is a positive electrode guide portion electrically connected to the positive electrode of one battery cell, and the other side is a negative electrode guide portion electrically connected to the negative electrode of another battery cell, so as to connect adjacent battery cells in series. SUMMARY OF THE INVENTION

[0005] Although the fusing structure provided between the positive electrode current guide portion and the negative electrode current guide portion satisfies the fusing requirement of the busbar, it reduces the overcurrent capacity of the busbar, thereby increasing the internal resistance of the battery module.

[0006] In the first aspect, an embodiment of the present application provides a busbar, which includes a busbar and a plurality of spaced-apart guides, the guides including a fuse part and a guide part, the melting point of the fuse part is lower than the melting points of the busbar and the guide part, the two ends of the fuse part are respectively connected to the guide part and the busbar, and the guide part is configured to be connected to the positive or negative pole of the battery cell.

[0007] In a second aspect, an embodiment of the present application provides a battery module, which includes the aforementioned busbar. Beneficial effects

[0008] The present application arranges the fuse part between the bus bar and the guide part so that the current gathered by the bus does not flow through the fuse part. In this way, the fuse part can meet the fusing requirements of the bus without affecting the current that the bus can carry, thereby improving the overcurrent capacity of the bus and reducing the internal resistance of the battery module. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG1 is a schematic structural diagram of a busbar provided in an embodiment of the present application;

[0010] FIG2 is a schematic diagram of a partial structure of a busbar provided in an embodiment of the present application;

[0011] Figure 3 is an enlarged view of point A in Figure 1;

[0012] FIG4 is an exploded view of a busbar provided in an embodiment of the present application.

[0013] Description of reference numerals:

[0014] 001-bus;

[0015] 011-flow guide, 111-flow guide portion, 1111-first through hole, 112-fuse portion, 1121-fuse hole;

[0016] 012-bus bar, 121-first bar body, 122-second bar body, 123-positioning hole, 124-second through hole. Modes for Carrying Out the Invention

[0017] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the specified features. In the description of this application, "plurality" means two or more, unless otherwise specifically specified.

[0018] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0019] In the description of the embodiments of this application, words such as "example" or "for example" are used to indicate an example, illustration, or description. Any embodiment or design described as "for example" or "for example" in the embodiments of this application is not to be construed as being preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to clearly present relative concepts.

[0020] Please refer to Figure 1, which is a schematic structural diagram of a busbar 001 provided in an embodiment of the present application. An embodiment of the present application provides a busbar 001. The busbar 001 includes a busbar 012 and a plurality of flow guides 011 arranged at intervals. The flow guide 011 includes a fuse part 112 and a flow guide part 111. The melting point of the fuse part 112 is lower than the melting points of the busbar 012 and the flow guide part 111. The two ends of the fuse part 112 are respectively connected to the flow guide part 111 and the busbar 012. The flow guide part 111 is configured to be connected to the positive or negative pole of the battery cell.

[0021] It can be understood that multiple flow guides 011 are spaced apart along the length direction of the busbar 012. Multiple flow guides 111 connected to the same busbar 012 are connected to the electrodes of the same polarity of multiple battery cells, thereby connecting the positive or negative electrodes of multiple battery cells in parallel. Accordingly, the battery module is configured with at least two busbars, one busbar connects the positive electrodes of multiple battery cells in parallel, and the other busbar connects the negative electrodes of multiple battery cells in parallel. Among them, the busbar 001 disclosed in this embodiment can be used only at the positive electrode of the battery cell, and the busbar connected to the negative electrode of the battery cell can use a conventional busbar.

[0022] Exemplarily, the melting point of the fuse 112 is less than 1000° C., and the melting points of the busbar 012 and the guide 111 are greater than 1000° C. When the current abnormally rises to a certain temperature, the fuse 112 melts itself to cut off the current, thereby disconnecting the battery circuit.

[0023] There are various ways to prioritize the melting of the fuse 112 over the busbar 012 and the current guide 111. For example, in one approach, the fuse 112 can be formed from a material with a lower melting point than that of the busbar 012 and the current guide 111, thereby achieving preferential melting of the fuse 112. In another example, in another approach, the cross-sectional area of ​​the fuse 112 perpendicular to the current transmission direction can be configured to be smaller than the cross-sectional area of ​​the current guide 111 and the cross-sectional area of ​​the busbar 012 perpendicular to the current transmission direction, thereby achieving preferential melting of the fuse 112.

[0024] In this embodiment, by arranging the fuse part 112 between the bus bar 012 and the guide part 111, the current gathered by the bus 001 does not pass through the fuse part 112 when flowing, so that the fuse part 112 can meet the fusing requirements of the bus 001 without affecting the current that the bus 001 can carry, thereby improving the current flow capacity of the bus 001 and reducing the internal resistance of the battery module.

[0025] Please refer to Figure 2, which is a schematic diagram of a partial structure of busbar 001 provided in an embodiment of the present application. In one embodiment, fuse portion 112 extends from busbar 012 toward guide portion 111. The extension direction of fuse portion 112 forms an acute or obtuse angle with the extension direction of busbar 012, so that the two ends of fuse portion 112 are staggered along the length of busbar 012.

[0026] In this embodiment, the extension direction of the fuse part 112 is set to form an acute angle or an obtuse angle with the extension direction of the busbar 012, so that the two ends of the fuse part 112 are staggered along the length direction of the busbar 012. Therefore, when the spacing between the guide part 111 and the busbar 012 is limited, the size of the fuse part 112 in the length direction of the busbar 012 can be increased, thereby making the size of the fuse part 112 meet the fusing requirements, and ultimately improving the reliability of the busbar 001.

[0027] In one embodiment, the second method is used to achieve preferential melting of the fuse 112. Specifically, the cross-sectional area of ​​the fuse 112 perpendicular to the current transmission direction is smaller than the cross-sectional area of ​​the guide portion 111 perpendicular to the current transmission direction and the cross-sectional area of ​​the busbar 012 perpendicular to the current transmission direction.

[0028] Exemplarily, the fuse portion 112 and the guide portion 111 are integrally formed.

[0029] In this embodiment, the preferential blowing of the fuse part 112 is achieved by limiting the size relationship of the cross-sectional area of ​​the current passing between the various components, so that the fuse part 112 and the guide part 111 can be formed of the same material, so that the fuse part 112 can be formed integrally with the guide part 111, thereby improving the molding efficiency of the guide part 011 and reducing the manufacturing difficulty of the bus 001.

[0030] In one embodiment, a fuse hole 1121 or a fuse slot is provided on the fuse portion 112 .

[0031] In this embodiment, by providing a fuse hole 1121 or a fuse groove on the fuse part 112, on the one hand, the cross-sectional area of ​​the fuse part 112 perpendicular to the current transmission direction can be made smaller through the provision of the fuse hole 1121 or the fuse groove; on the other hand, the fuse part 112 has a larger surface area, thereby improving the fusing reliability of the fuse part 112.

[0032] Specifically, when fuse portion 112 is provided with fuse hole 1121, as shown in FIG2 , fuse hole 1121 is a rounded hole in a strip shape, and the wall of fuse hole 1121 extends in the same direction as fuse portion 112. When fuse portion 112 is provided with a fuse slot, the slot is in a strip shape, and the wall of the slot extends in the same direction as fuse portion 112. This increases the length of the structure of fuse portion 112 for fusing, so that fusing at any location on the wall of fuse hole 1121 or any location on the wall of the slot can meet the fusing requirements, thereby improving the fusing reliability of fuse portion 112.

[0033] Please refer to FIG. 2 . In one embodiment, the fuse portion 112 is an arc-shaped structure, and two ends of the arc-shaped structure are respectively connected to the guide portion 111 and the bus bar 012 .

[0034] In this embodiment, through the above arrangement, when the distance between the two ends of the fuse portion 112 is constant, the fuse portion 112 can have a longer size, thereby further improving the reliability of the busbar 001.

[0035] Please refer to FIG. 1 . In one embodiment, the cross-sectional area of ​​the bus bar 012 perpendicular to the current transmission direction is larger than the cross-sectional area of ​​the guide member 011 perpendicular to the current transmission direction.

[0036] It can be understood that the current passing through busbar 012 is greater than the current passing through guide member 011. Therefore, in order to meet the overcurrent requirement of busbar 012, it is necessary to set the cross-sectional area of ​​busbar 012 perpendicular to the current transmission direction to a structure larger than the cross-sectional area of ​​guide member 011 perpendicular to the current transmission direction, so as to improve the reliability of busbar 001.

[0037] Exemplarily, 13 flow guides 011 are provided on one side of the busbar 012 .

[0038] In combination with the above embodiment, the bending direction of the fuse portion 112 of each guide member 011 can be consistent, or partially consistent and the other part opposite, as shown in Figure 1. The specific bending direction of the fuse portion 112 can be set accordingly according to different battery modules.

[0039] Please refer to FIG3 , which is an enlarged view of point A in FIG1 . In one embodiment, the thickness of the bus bar 012 is greater than the thickness of the flow guide 011 .

[0040] For example, the busbar 012 has a thickness of 2 to 2.6 mm, and the guide 011 has a thickness of 0.2 to 0.4 mm. It is understood that the thickness of the busbar 012 includes, but is not limited to, 2 mm, 2.1 mm, 2.2 mm, 2.4 mm, 2.5 mm, and 2.6 mm. The thickness of the guide 011 includes, but is not limited to, 0.2 mm, 0.21 mm, 0.22 mm, 0.3 mm, 0.35 mm, and 0.4 mm.

[0041] In this embodiment, the thickness of the busbar 012 is increased to achieve a larger cross-sectional area of ​​the busbar 012 perpendicular to the current transmission direction, which can reduce the surface area occupied by the busbar 012 in the battery module, thereby reducing the difficulty of arranging the busbar 001 and improving the installation efficiency of the busbar 001.

[0042] In one embodiment, the bus bar 012 and the flow guide 011 are integrally formed.

[0043] In this embodiment, the above configuration can improve the reliability of the connection between the bus bar 012 and the guide member 011 , thereby improving the reliability of the busbar 001 .

[0044] Please refer to Figure 4, which shows an exploded view of busbar 001 according to an embodiment of the present application. In one embodiment, along the thickness direction of busbar 012, busbar 012 includes a first strip 121 and a second strip 122 stacked in sequence. Second strip 122 is integrally formed with flow guide 011, and the thickness of second strip 122 is consistent with the thickness of flow guide 011.

[0045] It is understandable that when busbar 012 and flow guide 011 are integrally molded, the difference in thickness between busbar 012 and flow guide 011 makes molding more difficult. Therefore, in this embodiment, busbar 012 is configured as a structure composed of a first strip 121 and a second strip 122, with the thickness of second strip 122 being consistent with the thickness of flow guide 011. This allows the first strip 121 and the second strip 122, combined with flow guide 011, to be molded separately, each with a consistent overall thickness. This reduces the difficulty of molding busbar 001.

[0046] Furthermore, the first strip body 121 is welded to the second strip body 122. Specifically, the first strip body 121 and the second strip body 122 are integrated into one by laser welding.

[0047] In one embodiment, the melting point of the first strip 121 is greater than the melting point of the flow guide 011 .

[0048] Specifically, the material of the first strip body 121 may be copper, and the material of the second strip body 122 may be aluminum.

[0049] It is understood that the second strip 122 and the flow guide 011 are integrally formed, and therefore the second strip 122 and the flow guide 011 are made of the same material. Accordingly, the melting point of the first strip 121 is also greater than that of the flow guide 011.

[0050] In this embodiment, the above configuration can improve the overcurrent reliability of the busbar 012 and prevent the busbar 012 from being blown, thereby improving the reliability of the busbar 001 .

[0051] In one embodiment, the resistivity of the first strip 121 is lower than the resistivity of the second strip 122 .

[0052] It can be understood that the resistance of the first strip 121 is lower than the resistance of the second strip 122 .

[0053] Specifically, the material of the first strip body 121 may be copper, and the material of the second strip body 122 may be aluminum.

[0054] In this embodiment, through the above configuration, the flow conducting capacity of the busbar 001 can be improved and the material cost of the busbar 001 can be controlled.

[0055] In one embodiment, the busbar 001 is applied to a battery module. The battery module includes a battery cell. The battery cell has a pole. The guide portion 111 is provided with a first through hole 1111. The first through hole 1111 is configured to be aligned with the pole.

[0056] It is understood that a reference ring is provided on the end face of the pole, and the reference ring is coaxially arranged with the pole. When the first through hole 1111 can show a complete reference ring, it can be determined that the guide portion 111 is aligned with the pole.

[0057] In this embodiment, by providing the first through hole 1111 , it is convenient for relevant staff to quickly determine whether the busbar 001 is installed in place, thereby improving the convenience of assembling the busbar 001 .

[0058] The busbar 001 provided in the embodiment of the present application can be installed in the following manner: A positioning hole 123 and a second through-hole 124 are provided on the busbar 012. Positioning hole 123 is used to mate with a positioning post on the insulating bracket of the battery module. Second through-hole 124 mates with a screw. The end of the screw's shaft passes through second through-hole 124 and then threads into the insulating bracket, thereby securing the busbar 001 to the insulating bracket. The current guide 111 is then laser welded to the end of a battery electrode, such as the positive electrode.

[0059] Correspondingly, an embodiment of the present application further provides a battery module, which includes the aforementioned busbar.

[0060] It can be understood that the battery module also includes a battery cell, a battery cell bracket, etc. The battery cell is installed in the battery cell bracket, the collection bracket is fixed to the end of the battery cell, and the busbar is provided on the collection bracket and is electrically connected to the electrodes of the battery cell.

[0061] In this embodiment, by adopting the aforementioned busbar, the size of the fuse part 112 in the length direction of the busbar 012 can be increased when the distance between the guide part 111 and the busbar 012 is limited, so that the size of the fuse part 112 meets the fusing requirements, and ultimately the reliability of the battery module can be improved.

Claims

1. A busbar comprising: Busbar (012); A plurality of flow guides (011) are arranged at intervals, the flow guides (011) comprising a fuse part (112) and a flow guide part (111), the melting point of the fuse part (112) being lower than the melting points of the bus bar (012) and the flow guide part (111), two ends of the fuse part (112) being respectively connected to the flow guide part (111) and the bus bar (012), and the flow guide part (111) being configured to be connected to a positive electrode or a negative electrode of a battery cell.

2. The busbar according to claim 1, wherein: The fuse portion (112) is extended from the bus bar (012) toward the guide portion (111), and an extension direction of the fuse portion (112) forms an acute angle or an obtuse angle with an extension direction of the bus bar (012).

3. The busbar according to claim 1, wherein: The cross-sectional area of ​​the fuse portion (112) perpendicular to the current transmission direction is smaller than the cross-sectional area of ​​the guide portion (111) perpendicular to the current transmission direction and the cross-sectional area of ​​the bus bar (012) perpendicular to the current transmission direction.

4. The busbar according to claim 3, wherein: The fuse portion (112) is provided with a fuse hole (1121) or a fuse groove.

5. The busbar according to claim 4, wherein: The fuse hole (1121) is strip-shaped, and the extension direction of the hole wall of the fuse hole (1121) is consistent with the extension direction of the fuse portion (112).

6. The busbar according to claim 4, wherein: The fuse slot is strip-shaped, and the extension direction of the slot wall of the fuse slot is consistent with the extension direction of the fuse portion (112).

7. The busbar according to any one of claims 1 to 6, wherein: The fuse portion (112) is an arc-shaped structure, and two ends of the arc-shaped structure are respectively connected to the guide portion (111) and the bus bar (012).

8. The busbar according to any one of claims 1 to 6, wherein: The cross-sectional area of ​​the busbar (012) perpendicular to the current transmission direction is greater than the cross-sectional area of ​​the current guide (011) perpendicular to the current transmission direction.

9. The busbar according to claim 8, wherein: The thickness of the bus bar (012) is greater than the thickness of the flow guide (011).

10. The busbar according to claim 9, wherein Along the thickness direction of the bus bar (012), the bus bar (012) comprises a first bar body (121) and a second bar body (122) stacked in sequence, the second bar body (122) and the flow guide (011) are integrally formed, and the thickness of the second bar body (122) is consistent with the thickness of the flow guide (011).

11. The busbar according to claim 10, wherein: The resistivity of the first strip (121) is lower than the resistivity of the second strip (122).

12. The busbar according to any one of claims 1 to 6, wherein: The busbar (001) is applied to a battery module, the battery module comprises a battery cell, the battery cell has a pole, the guide portion (111) is provided with a first through hole (1111), and the first through hole (1111) is configured to be aligned with the pole.

13. A battery module comprising the busbar (001) according to any one of claims 1 to 12.

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