Busbar assembly and battery module

Abstract

The utility model discloses a busbar assembly and a battery module, the busbar assembly comprises a bar sheet, a copper layer is arranged on the peripheral surface of the bar sheet, and a first connecting part is formed on the bar sheet; a second connecting part is formed on the flexible circuit board, and the bar piece and the flexible circuit board are connected through the first connecting part and the second connecting part and conduct electricity. According to the busbar assembly provided by the utility model, the copper layer is arranged on the peripheral surface of the busbar, so that the conductivity of the busbar is improved, the resistance of the busbar is reduced, the electrical efficiency of a battery pack is improved, the copper layer effectively prevents electrochemical corrosion between aluminum and copper, and the service life of a connecting part is prolonged; the reliability and the stability of the busbar assembly are improved, and the production cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of battery manufacturing technology, and in particular to a busbar assembly and a battery module. Background Technology

[0002] Related technologies indicate that with advancements in lithium battery technology and the growing demand for super-fast charging, the fast charging rate of battery packs in newly launched electric vehicles is continuously increasing. Many battery packs now boast peak charging rates exceeding 4C, and the cell capacity used in these packs is typically above 100Ah. For example, current 800V fast-charging models mostly use cells with capacities around 150Ah. If the peak charging rate is ≥4C, the peak current exceeds 600Ah. Because aluminum electrodes are relatively soft and effectively absorb cell expansion, and the cell terminals are made of aluminum, welded from the same material, there are no electrochemical corrosion issues. Furthermore, aluminum has good conductivity and is inexpensive; therefore, most conductive electrodes currently used are made of aluminum.

[0003] The current mainstream solution for acquiring cell voltage and temperature is usually flexible printed circuit board (FPC). However, because FPC requires chemical etching, which is not environmentally friendly, has a complex manufacturing process, and low production efficiency, the cost of FPC acquisition boards has not been able to be reduced. In order to reduce costs and simplify the process, some manufacturers have launched CCS solutions that use mechanically cut circuit boards (FDC) and FFC with lower material costs.

[0004] 1. To achieve high current carrying capacity, current aluminum bars require increased cross-sectional area, either by thickening or widening. To ensure reliable and consistent welding, and to maintain a certain stretchable distance to prevent leakage due to stress on the battery terminals, the maximum thickness of the aluminum bar is typically within 2.5mm, and the thickness of the welding area must be controlled within 1.5mm. When the thickness cannot be increased to increase current carrying capacity, the width must be increased. To avoid affecting the stretching effect of the aluminum bar, and when the width of the aluminum bar cannot be widened due to surrounding space limitations, a layered design is usually required, necessitating bending dies, which increases the average cost of the aluminum bar.

[0005] 2. The conductive layer of the die-cut FDC is made of copper foil. Direct welding of copper foil and aluminum foil to the battery pack presents an electrochemical corrosion problem. In the high-temperature and certain humidity environment of the battery pack, long-term use can easily lead to corrosion at the weld joints, resulting in increased or abnormal electrical connection resistance. To solve this, the FDC is usually connected to the battery pack via a nickel strip. However, the nickel strip is typically placed on the FDC and requires reflow soldering, increasing the energy consumption and time required, significantly impacting FDC production efficiency and reducing the cost reduction ratio, thus failing to achieve the lowest possible cost. The lower-cost FFC solution, with its copper conductive flat wire, also suffers from electrochemical corrosion due to the copper material, requiring additional nickel strip connections, resulting in higher labor costs and less significant overall cost reduction for CCS. Utility Model Content

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a busbar assembly that has low production cost and good stability.

[0007] This utility model also proposes a battery module having the above-mentioned busbar assembly.

[0008] According to a first aspect of the present invention, a bus assembly includes: a busbar, wherein a copper layer is provided on the outer peripheral surface of the busbar, and the busbar has a first connecting portion; and a flexible circuit board, wherein the flexible circuit board has a second connecting portion, and the busbar and the flexible circuit board are connected and conductive through the first connecting portion and the second connecting portion.

[0009] According to the present invention, the busbar assembly improves the conductivity of the battery pads and reduces their resistance by setting a copper layer on the outer peripheral surface of the battery pads, thereby increasing the electrical efficiency of the battery pack. The copper layer effectively prevents electrochemical corrosion between aluminum and copper, extends the service life of the connection parts, improves the reliability and stability of the busbar assembly, and reduces production costs.

[0010] In some embodiments, the flexible circuit board includes: a first film layer, a conductive layer, and a second film layer, wherein the conductive layer is located between the first film layer and the second film layer, and both the first film layer and the second film layer have through holes formed at the second connection portion to expose the conductive layer.

[0011] In some embodiments, the second connecting portion is provided with a connecting member in the circumferential direction.

[0012] In some embodiments, the flexible circuit board includes a body and a connecting plate, one end of the connecting plate is connected to the body, the second connecting portion is formed at the other end of the connecting plate, and a buffer is formed on the connecting plate.

[0013] In some embodiments, the flexible circuit board is welded to the plate.

[0014] In some embodiments, a nickel sheet is connected between the flexible circuit board and the plate.

[0015] In some embodiments, the bus assembly further includes a flat cable welded to the bus plate.

[0016] In some embodiments, a thinning zone is formed on the plaster.

[0017] In some embodiments, the bar sheet is an aluminum bar sheet, and the thickness of the bar sheet is 1mm-2mm, and the thickness of the copper layer is 0.1mm-1.5mm.

[0018] The battery module according to the second aspect of the present invention includes the bus assembly according to the first aspect of the present invention.

[0019] According to the present invention, by setting the busbar assembly of the first aspect, the current carrying capacity of the battery module is improved, the production cost of the battery module is reduced, and the safety and reliability of the battery module are guaranteed.

[0020] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a busbar assembly according to an embodiment of the present utility model;

[0022] Figure 2 yes Figure 1 A schematic diagram of the bus assembly shown from another angle;

[0023] Figure 3 yes Figure 1 A schematic diagram of the flexible circuit board shown;

[0024] Figure 4 yes Figure 3 A schematic diagram of the flexible circuit board from another angle;

[0025] Figure 5 yes Figure 3 A partially enlarged schematic diagram of the flexible circuit board shown;

[0026] Figure 6 This is a schematic diagram of a bus assembly according to another embodiment of the present invention.

[0027] Figure label:

[0028] 100. Busbar assembly; 1. Panel; 11. Thinning zone; 2. Flexible circuit board; 21. Second connection part; 22. Connecting plate; 221. Buffer zone; 23. Body; 3. Nickel sheet; 4. Flat cable; Detailed Implementation

[0029] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0030] The following is for reference. Figures 1-5 A bus assembly 100 according to a first aspect embodiment of the present invention is described.

[0031] like Figures 1-4 As shown, the bus assembly 100 according to the first aspect of the present invention includes: a plate 1 and a flexible circuit board 2.

[0032] Specifically, the outer peripheral surface of the aluminum plate 1 is provided with a copper layer, and the aluminum plate 1 has a first connecting portion. Second connecting portions 21 are formed on both sides of the flexible circuit board 2 in the width direction. The aluminum plate 1 and the flexible circuit board 2 are connected and electrically conductive through the first connecting portion and the second connecting portion 21. It is understood that the copper layer on the outer peripheral surface of the aluminum plate 1 primarily provides excellent conductivity while reducing the risk of electrochemical corrosion between the aluminum plate and the flexible circuit board 2 (FDC / FFC). The first connecting portion is used to mate with the second connecting portion 21 on the flexible circuit board 2, ensuring a reliable electrical connection between the two.

[0033] According to the embodiment of the present utility model, the bus assembly 100 improves the conductivity of the battery pack by providing a copper layer on the outer peripheral surface of the battery pack 1, reduces the resistance of the battery pack 1, improves the electrical efficiency of the battery pack, effectively prevents electrochemical corrosion between aluminum and copper, extends the service life of the connection parts, improves the reliability and stability of the bus assembly 100, and reduces the production cost.

[0034] In some embodiments of this utility model, the flexible circuit board 2 includes: a first film layer, a conductive layer, and a second film layer. The conductive layer is located between the first film layer and the second film layer. Both the first film layer and the second film layer have through holes formed at the second connection portion 21 to expose the conductive layer. It is understood that the first film layer and the second film layer are located on the outermost sides of the flexible circuit board 2 in the thickness direction, and are typically made of insulating materials such as polyimide (PI) and polyester (PET), serving to protect the conductive layer and provide insulation. The conductive layer is located between the first film layer and the second film layer, and is typically made of copper foil for conduction. At the second connection portion 21, both the first film layer and the second film layer have through holes, exposing the conductive layer at the second connection portion 21. This ensures that the conductive layer can directly contact the first connection portion of the circuit board 1, forming a reliable electrical connection, ensuring an efficient conductive path, and reducing contact resistance.

[0035] In some embodiments of this utility model, the second connecting part 21 is provided with a connector in the circumferential direction. The connector can be double-sided adhesive, which provides additional adhesive force between the flexible circuit board 2 and the battery pack 1, ensuring a firm mechanical connection between the two. In the vibration and impact environment inside the battery pack, it can prevent the connection from loosening or falling off, and reduce the impact of mechanical vibration on the electrical connection, thereby improving the overall stability of the system.

[0036] In some embodiments of this utility model, the flexible circuit board 2 includes a body 23 and a connecting plate 22. One end of the connecting plate 22 is connected to the body 23, and a second connecting portion 21 is formed at the other end of the connecting plate 22. A buffer zone 221 is formed on the connecting plate 22. It can be understood that one end of the connecting plate 22 is fixedly connected to the body 23 to form a continuous whole, and the other end of the connecting plate 22 has a second connecting portion 21 for docking with the first connecting portion of the plate 1 to ensure electrical connection. The buffer zone 221 formed on the connecting plate 22 is used to absorb and disperse stress, improve the reliability and durability of the connection, and enable the flexible circuit board 2 to maintain good performance under different environments and working conditions.

[0037] In some embodiments of this utility model, the outer peripheral surface of the bar sheet 1 is provided with a copper layer, so the flexible circuit board 2 and the bar sheet 1 are directly bonded and welded together.

[0038] Welding methods can be selected as follows: Ultrasonic welding: Suitable for joining aluminum and copper, it uses the heat and pressure generated by ultrasonic vibrations to fuse the metal materials together, forming a strong connection. Laser welding: Suitable for precision welding, it uses a laser beam to heat the solder, achieving fast and precise welding. Resistance welding: Suitable for thicker metal materials, it uses the heat generated by an electric current to melt the metal and form a weld point. Reflow soldering: Suitable for mass production, it pre-coats the welding area with solder, and heats it to melt and solidify the solder, forming a stable weld point.

[0039] Preferably, the welding method is ultrasonic welding.

[0040] In some embodiments of this utility model, when laser welding is used, a nickel sheet 3 is connected between the flexible circuit board 2 and the plate 1 to increase the welding pull-out force. It can be understood that the nickel sheet 3 serves as an intermediate layer to connect the flexible circuit board 2 and the plate 1. One side of the nickel sheet 3 is welded to the second connecting part 21 of the flexible circuit board 2, and the other side is welded to the first connecting part of the plate 1.

[0041] In some embodiments of this utility model, the bus assembly 100 further includes a flat cable 4, which is welded to the plate 1. This further improves the reliability and flexibility of the bus assembly 100, not only solving the electrochemical corrosion problem between copper and aluminum, but also improving conductivity and connection reliability. In high-power-density battery pack applications, it can effectively enhance the overall performance and lifespan of the battery module.

[0042] In some embodiments of this invention, to prevent the welding zone temperature from being too high and affecting the maximum current carrying capacity, a thinning zone 11 is formed on the plate 1, and the thinning zone 11 is formed in an annular shape. Preferably, the thinning zone 11 is adapted to the direction of the weld bead.

[0043] In some embodiments of this utility model, the electrode plate 1 is an aluminum electrode plate, and the thickness of the electrode plate 1 is 1mm-2mm, while the thickness of the copper layer is 0.1mm-1.5mm. For example, the thickness of the electrode plate 1 can be 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, etc.; and the thickness of the copper layer can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, etc.

[0044] Specifically, the usable width of the conductive bar 1 for existing 150Ah battery cells is typically around 50-70mm, since the current carrying capacity of aluminum conductive bars is 3A / mm. 2 The conductivity of copper is 5 A / mm². 2 Assuming the aluminum layer thickness is 1.5mm and the copper layer thickness is 1mm, then 1.5*3*X+1*5*X=600, so X=64.2mm. The width of bar plate 1 is 64.2mm, which can meet the 600A current carrying requirement.

[0045] The battery module according to a second aspect of the present invention includes a bus assembly 100 according to the first aspect of the present invention described above.

[0046] According to the battery module of the present invention, by setting the busbar assembly 100 of the first aspect embodiment, the current carrying capacity of the battery module is improved, the production cost of the battery module is reduced, and the safety and reliability of the battery module are guaranteed.

[0047] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0048] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined.

[0049] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0050] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0051] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A bus assembly, characterized in that, include: A plate, wherein a copper layer is provided on the outer peripheral surface of the plate, and the plate has a first connecting portion; A flexible circuit board having a second connection portion, wherein the pad is connected to the flexible circuit board via the first connection portion and the second connection portion and is electrically conductive.

2. The bus assembly according to claim 1, characterized in that, The flexible circuit board includes: a first film layer, a conductive layer, and a second film layer. The conductive layer is located between the first film layer and the second film layer. Both the first film layer and the second film layer have through holes formed at the second connection portion to expose the conductive layer.

3. The bus assembly according to claim 2, characterized in that, The second connecting part is provided with a connector in the circumferential direction.

4. The bus assembly according to claim 3, characterized in that, The flexible circuit board includes a body and a connecting plate. One end of the connecting plate is connected to the body, and a second connecting portion is formed at the other end of the connecting plate. A buffer zone is formed on the connecting plate.

5. The bus assembly according to claim 4, characterized in that, The flexible circuit board is welded to the plate.

6. The bus assembly according to claim 4, characterized in that, A nickel sheet is connected between the flexible circuit board and the plate.

7. The bus assembly according to any one of claims 1-6, characterized in that, Also includes: A flat cable, which is welded to the plate.

8. The bus assembly according to any one of claims 1-6, characterized in that, Thinning zones are formed on the plaster.

9. The bus assembly according to any one of claims 1-6, characterized in that, The bar sheet is made of aluminum, and the thickness of the bar sheet is 1mm-2mm, while the thickness of the copper layer is 0.1mm-1.5mm.

10. A battery module, characterized in that, The bus assembly included in any one of claims 1-9.

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