Busbars, battery packs and electronic devices

Abstract

This application belongs to the technical field of batteries and discloses a busbar, a battery pack, and an electronic device, in which the busbar includes an aluminum bar and two copper sleeves, the aluminum bar has mounting holes at both ends, the two copper sleeves are fixed to the mounting holes in a one-to-one correspondence, the copper sleeves are electrically connected to the aluminum bar, one of the two copper sleeves is for electrically connecting to a battery module, and the other is for electrically connecting to an external device.

Description

[Technical Field]

[0001] Related Application This application claims priority to a Chinese patent application bearing application number 202222923249.2, filed with the State Intellectual Property Office of the People's Republic of China on November 3, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the technical field of batteries, and more particularly to bus bars, battery packs and electronic devices. [Background technology]

[0003] Currently used power battery packs all contain multiple battery modules. Busbars are usually used for electrical connection between two adjacent battery modules or between a battery module and the power output port of the battery pack. Busbars in the prior art are mainly made of copper bars, and some busbars also have the structure of welding terminals for wire harnesses.

[0004] Copper bars, also known as bus copper bars or copper bus bars, are made of copper and serve to transmit current in circuits and connect electrical devices. Power bus bars can carry large currents and are commonly used in electrical engineering for high- and low-voltage electrical devices, switch contacts, power distribution devices, bus ducts, etc. Copper bars have the advantages of low resistivity and good bendability, but power battery packs require a large number of copper bars. Because copper bars are made of copper or copper alloy, their unit weight is heavy and their manufacturing costs are high, which limits the development of lightweight new energy vehicles and keeps the manufacturing costs of new energy vehicles high.

[0005] Therefore, there is an urgent need to improve the prior art to solve the technical problems existing in existing busbars. Summary of the Invention

[0006] In a first aspect, the present application provides a busbar that can reduce weight, raw material costs, and manufacturing costs without affecting electrical conductivity performance.

[0007] This application adopts the following technical solution: the busbar includes an aluminum bar and two copper sleeves, mounting holes are drilled at both ends of the aluminum bar, the two copper sleeves are fixed to the two mounting holes in a one-to-one correspondence, the copper sleeves are electrically connected to the aluminum bar, one of the two copper sleeves is for electrically connecting to a battery module, and the other is for electrically connecting to an external device.

[0008] In one embodiment, the copper sleeve has a connection hole, and the copper sleeve is connected to the battery module or the external device by a bolt, and the bolt is inserted through the connection hole.

[0009] In one embodiment, both vertical end faces of the copper sleeve are higher than the mounting holes.

[0010] In one embodiment, the area of ​​the upper end surface of the copper sleeve is equal to or greater than the area of ​​the lower end surface of the head flange of the bolt.

[0011] In one embodiment, the aforementioned connecting hole of one of the two aforementioned copper sleeves is an oblong hole.

[0012] In one embodiment, the copper sleeve is secured to the mounting hole by friction welding.

[0013] In one embodiment, the outer surface of the aluminum bar is electroplated with a protective layer.

[0014] In one embodiment, the outer surface of the aluminum bar is coated with an insulating layer.

[0015] In one embodiment, the aluminum bar is formed by bending an aluminum plate, and both ends of the aluminum bar are rounded and chamfered. In a second aspect, the present application provides a battery pack including a plurality of battery modules and the bus bar according to any one of the solutions above, wherein the bus bar is installed between two adjacent battery modules or between the battery module and an output end of the battery pack.

[0016] In a third aspect, the present application provides an electronic device including a battery pack according to the aforementioned solution. [Effects of the Invention]

[0017] The busbar of this application has two copper sleeves fixed respectively within two mounting holes in the aluminum bar, allowing the copper sleeves to be electrically connected to the aluminum bar. One of the copper sleeves is used to electrically connect to the battery module, and the other is used to electrically connect to an external device. The excellent conductivity of the copper sleeve is used to draw current from the battery module. The body of the busbar is an aluminum bar, which has excellent conductivity, is easy to process, and has a low aluminum density and low material cost. Therefore, replacing the copper bar of the original busbar with an aluminum bar can significantly reduce the weight and manufacturing cost of the busbar without affecting the busbar's conductivity performance. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 2 is a schematic diagram of a busbar provided by an embodiment of the present application. [Figure 2] FIG. 2 is a schematic diagram of a bus bar provided by an embodiment of the present application attached to a battery module. DETAILED DESCRIPTION OF THE INVENTION

[0019] In the description of this application, unless otherwise expressly specified and limited, the terms "coupled," "connected," and "fixed" should be understood in a broad sense. For example, they may be fixedly connected or detachably connected, or integral, may be mechanically connected, electrically connected, directly connected or indirectly connected through an intermediate medium, or may be communication within two components or interaction between two components. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0020] Unless otherwise expressly specified and defined in this application, a first element being "above" or "below" a second element may mean that the first and second elements are in direct contact, or that the first and second elements are not in direct contact but are in contact via another element between them. Furthermore, a first element being "above," "above," or "on top" of a second element may mean that the first element is directly above or diagonally above the second element, or may simply mean that the first element is at a higher horizontal level than the second element. A first element being "below," "below," or "below" a second element may mean that the first element is directly below or diagonally below the second element, or may simply mean that the first element is at a lower horizontal level than the second element.

[0021] In the description of the present embodiment, directional or positional relationships such as "upper," "lower," and "right" are directional or positional relationships shown based on the drawings, and are used only to facilitate description and simplify operation, and do not expressly or imply that the indicated devices or elements must have a specific orientation or be constructed or operated in a specific orientation, and are not to be understood as limitations of the present application. Note that the terms "first" and "second" are used merely for distinction in description and do not have any special meaning.

[0022] Referring to FIG. 1 , in this embodiment, the bus bar 100 includes an aluminum bar 110 and two copper sleeves 120. Mounting holes 111 are drilled at both ends of the aluminum bar 110. The two copper sleeves 120 are fixed in the mounting holes 111 in a one-to-one correspondence, and the copper sleeves 120 are electrically connected to the aluminum bar 110. One of the two copper sleeves 120 is electrically connected to a battery module, and the other is electrically connected to an external device. The external device referred to here may include another battery module, the output terminal of a battery pack including the battery module, or other electronic devices. Those skilled in the art can use the bus bar 100 to electrically connect battery modules to other external devices according to specific needs, and no particular limitations are placed here.

[0023] In this embodiment, the busbar 100 has two copper sleeves 120 fixed in two mounting holes 111 of the aluminum bar 110, respectively, so that the copper sleeves 120 are electrically connected to the aluminum bar 110. One of the copper sleeves 120 is used for electrical connection to the battery module, and the other copper sleeve 120 is used for electrical connection to an external device. The excellent conductivity of the copper sleeve 120 is used to draw current from the battery module. The main body of the busbar 100 is the aluminum busbar 110, which has excellent conductivity, is easy to process, and has low aluminum density and low material costs. Therefore, replacing the copper bar of the original busbar 100 with the aluminum bar 110 significantly reduces the weight and manufacturing costs of the busbar 100 without affecting the electrical conductivity of the busbar 100.

[0024] Continuing to refer to Figure 1, in this embodiment, the copper sleeve 120 has a connection hole 121, and the copper sleeve 120 is connected to the battery module or the external device by a bolt 210, which penetrates the connection hole 121. The bus bar 100 connected by the bolt 210 is easy to install and remove, has higher connection reliability and stability, and ensures that the bus bar 100 will not come off the battery module.

[0025] Optionally, the connecting hole 121 of one of the two copper sleeves 120 is an oval hole. In this embodiment, the connecting hole 121 of the copper sleeve 120 connected to an external device is an oval hole. An oval hole is also called an oblong hole, and its both ends are semicircular arcs and the center is a parallel plane. The oval hole design reduces the difficulty in machining the connecting holes 121 of the two copper sleeves 120 and positioning and installing the copper sleeves. The width of the center plane of the oval hole can be smaller than the diameter of the head flange 211 of the bolt 210.

[0026] Furthermore, both vertical end surfaces of the copper sleeve 120 are higher than the mounting hole 111. In this embodiment, when the copper sleeve 120 is fixed in the mounting hole 111, the upper end surface of the copper sleeve 120 is higher than the mounting hole 111, and the lower end surface of the copper sleeve 120 also protrudes from the mounting hole 111. This allows the copper sleeve 120 to make sufficient contact with the head flange 211 of the bolt 210 and the battery module or an external device, ensuring that the electrical connection of the copper sleeve 120 with the battery module or an external device is not affected and that the current and voltage are more stable.

[0027] In a preferred embodiment, the area of ​​the upper end surface of the copper sleeve 120 is equal to or greater than the area of ​​the lower end surface of the head flange 211 of the bolt 210. When the copper sleeve 120 is configured in this manner, the head flange 211 is in full contact with the copper sleeve 120 when the bolt 210 is tightened, and sufficient pressure is applied to the copper sleeve 120 to secure the copper sleeve 120 to the battery module or an external device, resulting in a more stable electrical connection and more stable current and voltage.

[0028] Specifically, the copper sleeve 120 is fixed to the mounting hole 111 by friction welding. Friction welding is a method of heating and melting the friction surfaces by utilizing the frictional heat generated by friction between thermoplastic plastics, and joining them after applying pressure and cooling. In addition to the advantages of general thermocompression welding, friction welding has the advantages of producing high-quality and stable welded joints, high dimensional accuracy and shape accuracy of the welded parts, reduced manufacturing costs, high welding efficiency, and environmental friendliness.

[0029] Furthermore, a protective layer is electroplated on the outer surface of the aluminum bar 110. The protective layer is formed by electroplating to protect the joint between the aluminum bar 110 and the copper sleeve 120 after welding, prevent damage to the joint due to corrosion, and improve the service life and reliability of the bus bar 100.

[0030] In a preferred embodiment, the outer surface of the aluminum bar 110 is coated with an insulating layer 112. Specifically, the insulating layer 112 is formed by rubber immersion insulation. The insulating layer 112 ensures that the bus bar 100 does not come into contact with other bus bars 100 or other current-carrying devices after installation, preventing short circuits and improving the safety of the bus bar 100. Preferably, the aluminum bar 110 is formed by bending an aluminum plate, and both ends of the aluminum bar 110 are rounded and chamfered.

[0031] Specifically, aluminum bar 110 in this embodiment is made by 3D bending an aluminum plate 1000 mm long, 20 mm wide, and 3 mm thick into a desired shape, but there are no particular limitations. If the aluminum plate is simply bent to form it, the four corners of the aluminum plate will be relatively sharp. Therefore, by rounding both ends of aluminum bar 110, tip discharges can be prevented and the safety of bus bar 100 can be further improved.

[0032] Continuing with reference to FIG. 2, FIG. 2 is a schematic diagram showing the busbar 100 attached to a battery module. In FIG. 2, only the end plate 220 and the CCS assembly 230 of the battery module are shown, with the busbar 100 fixed to the end plate 220 by bolts 210 and electrically connected to the CCS assembly 230. This embodiment further provides a battery pack including a plurality of battery modules and the busbar 110 of any of the above solutions, with the busbar 100 installed between two adjacent battery modules or between the battery module and the output end of the battery pack. The battery pack using the busbar 100 of the above solutions not only significantly reduces the overall mass but also reduces manufacturing costs.

[0033] This embodiment also provides an electronic device including the battery pack described in the above solution. Specifically, the electronic device described in this embodiment is a car. The car using the battery pack described above can reduce its weight, thereby improving its driving range and reducing the overall cost of the vehicle. [Explanation of symbols]

[0034] 100 Busbar 110 Aluminum bar 111 Mounting hole 112 Insulating layer 120 Copper sleeve 121 Connection hole 210 volts 211 Head flange 220 End plate 230 CCS Assembly.

Claims

1. A bus bar comprising an aluminum bar (110) and two copper sleeves (120); Mounting holes (111) are drilled at both ends of the aluminum bar (110), The two copper sleeves (120) are fixed to the two mounting holes (111) in a one-to-one correspondence, the copper sleeves (120) are electrically connected to the aluminum bar (110), and one of the two copper sleeves (120) is for electrically connecting to a battery module, and the other is for electrically connecting to an external device.

2. 2. The busbar according to claim 1, wherein the copper sleeve (120) has a connection hole (121), the copper sleeve (120) is connected to the battery module or the external device by a bolt (210), and the bolt (210) is inserted through the connection hole (121).

3. The bus bar according to claim 2, wherein both vertical end surfaces of the copper sleeve (120) are higher than the mounting holes (111).

4. 3. The busbar according to claim 2, wherein the area of ​​the upper end surface of the copper sleeve (120) is equal to or greater than the area of ​​the lower end surface of the head flange (211) of the bolt (210).

5. The busbar according to claim 2, characterized in that the connection hole (121) of one of the two copper sleeves (120) is an oblong hole.

6. 2. The busbar of claim 1, wherein the copper sleeve (120) is fixed to the mounting hole (111) by friction welding.

7. The bus bar according to claim 6, characterized in that the outer surface of the aluminum bar (110) is electroplated with a protective layer.

8. The bus bar according to any one of claims 1 to 7, characterized in that an outer surface of the aluminum bar (110) is coated with an insulating layer (112).

9. 8. The bus bar according to claim 1, wherein the aluminum bar is formed by bending an aluminum plate, and both ends of the aluminum bar are rounded and chamfered.

10. A battery pack comprising a plurality of battery modules and the bus bar (100) according to any one of claims 1 to 7, wherein the bus bar (100) is installed between two adjacent battery modules or between the battery modules and an output end of the battery pack.

11. An electronic device comprising the battery pack of claim 10.

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