Flexible circuit board of battery module and battery pack

Abstract

The utility model discloses a flexible circuit board of a battery module, and the flexible circuit board comprises a plugging terminal which is located at one end of the flexible circuit board in the length direction; the number of the nickel sheets is multiple, and the multiple nickel sheets are arranged at intervals in the length direction; the lead and the nickel sheet are respectively and independently connected with the plugging terminal through the lead; wherein the length of the wire and the width of the wire meet the following conditions: the length of the wire is less than or equal to 0.5 m, and the width of the wire is 0.444-0.500 mm; the length of the wire is greater than 0.5 m and less than or equal to 1m, and the width of the wire is 0.889-1.000 mm; the length of the wire is larger than 1m and smaller than or equal to 1.5 m, and the width of the wire is 1.333 mm to 1.500 mm. The utility model further discloses a battery pack. The flexible circuit board provided by the utility model effectively reduces the line resistance difference of the acquisition line of the whole battery module, thereby effectively reducing the voltage drop of the acquisition line and improving the acquisition accuracy.

Description

Technical Field

[0001] The utility model relates to the field of batteries, and in particular to a flexible circuit board of a battery module and a battery pack. Background Art

[0002] The CCS (Cells Contact System) assembly used in battery modules typically consists of an output aluminum busbar protective cover, a blister pack, an FPC (Flexible Printed Circuit) (FPC), and an aluminum busbar. The FPC is a flexible printed circuit board (FPC). In FPC data acquisition solutions, nickel sheets and wires form the data acquisition circuit. Considering the impact of wires on the wiring resistance of the data acquisition circuit and the FPC width requirements of battery modules, the wires in the data acquisition circuit typically use a 0.5mm wire width.

[0003] However, for battery modules with a line length exceeding 1m, when the FPC acquisition line adopts a line width of 0.5mm, the impedance difference of the acquisition line is large, resulting in a large voltage difference in the acquisition line. The cell voltage data collected by the BMS (battery management system) is inaccurate, affecting the use of the battery. Utility Model Content

[0004] In order to solve the above technical problems, the embodiments of the present invention provide a flexible circuit board and a battery pack of a battery module.

[0005] In a first aspect, an embodiment of the present utility model discloses a flexible circuit board of a battery module, comprising:

[0006] A plug-in terminal is located at one end of the flexible circuit board in the length direction;

[0007] Nickel sheets, wherein the nickel sheets are provided in plurality and the plurality of nickel sheets are spaced apart along the length direction;

[0008] Wires, each of the nickel sheets is independently connected to the plug-in terminals via the wires;

[0009] The length and width of the wire satisfy the following conditions:

[0010] The length of the wire is ≤0.5m, and the wire width is 0.444mm~0.500mm;

[0011] 0.5m<the length of the wire≤1.0m, and the wire width of the wire is 0.889mm~1.000mm;

[0012] 1m<the length of the conductive wire≤1.5m, and the wire width of the conductive wire is 1.333mm~1.500mm.

[0013] The above technical solution can effectively reduce the line resistance difference of the entire battery module acquisition line, thereby effectively reducing the voltage drop of the acquisition line, while ensuring that the width of the flexible circuit board meets the requirements of the battery module.

[0014] Optionally, the conductive wire is a copper wire.

[0015] Optionally, the length and width of the copper wire satisfy:

[0016] The length of the copper wire is ≤0.5m, and the width of the copper wire is 0.486mm-0.500mm;

[0017] 0.5m<the length of the copper wire≤1m, and the width of the copper wire is 0.970mm~1.000mm;

[0018] 1m<the length of the copper wire≤1.5m, and the width of the copper wire is 1.458mm~1.500mm.

[0019] Optionally, a buffer wall is further included, and there are multiple buffer walls, which are spaced apart along the length direction, and the nickel sheet is at least partially located on the buffer wall.

[0020] Optionally, the wire is fixedly connected to the plug terminal by welding.

[0021] Optionally, the battery module further includes an aluminum bar and a battery cell, and the aluminum bar and the battery cell are fixedly connected.

[0022] Optionally, the nickel sheet and the aluminum bar are fixedly connected.

[0023] Optionally, the wire is fixedly connected to the nickel sheet by welding.

[0024] In a second aspect, an embodiment of the present invention further discloses a battery pack, comprising a flexible circuit board of the battery module in any embodiment of the first aspect.

[0025] The adoption of the above technical solution can improve the accuracy of battery pack data collection and further enhance the safety performance of the battery pack.

[0026] Optionally, a battery management system is further included, and the battery management system is connected to the plug terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic top view of a flexible circuit board according to an embodiment of the present invention is shown;

[0028] Figure 2 A schematic top view of a battery module according to an embodiment of the present invention is shown;

[0029] Figure 3 A schematic diagram showing the line width of the conductive wire according to an embodiment of the present invention is shown.

[0030] 1. Flexible circuit board, 11. Connector terminal, 12. Nickel sheet, 13. Wire, 14. Buffer wall, 2. Aluminum busbar, 3. Battery cell

[0031] d. Line width, L1. First line, L2. Second line, L3. Third line, L4. Fourth line, L5. Fifth line

[0032] X. Length direction, Y. Width direction DETAILED DESCRIPTION

[0033] The following is an explanation of the implementation of the present invention by means of specific specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this utility model are limited to this implementation. On the contrary, the purpose of introducing the utility model in conjunction with the implementation is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide an in-depth understanding of the present invention, the following description will contain many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0034] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0035] The terms “first”, “second”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0036] In the description of this embodiment, it should be noted that, unless otherwise specified or limited, the terms "disposed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this embodiment based on specific circumstances.

[0037] In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0038] First, as Figure 1 and Figure 2 As shown, the embodiment of the present utility model discloses a flexible circuit board 1 of a battery module, comprising:

[0039] The plug-in terminal 11 is located at one end of the length direction of the flexible circuit board 1. Figure 1 The X direction shown in ;

[0040] Nickel sheet 12, nickel sheet 12 has multiple, multiple nickel sheets 12 along the length direction (for example Figure 1 Specifically, the nickel sheet 12 is also provided on both sides of the flexible circuit board 1 along the width direction of the flexible circuit board 1, the width direction is for example Figure 1 Y direction shown.

[0041] The wires 13 and nickel sheets 12 are each independently connected to the plug-in terminal 11 via a wire 13. That is, each nickel sheet 12 is connected to the plug-in terminal 11 via a separate wire 13. Since the nickel sheets 12 are spaced apart along the length, the flexible circuit board 1 has multiple wires 13 of varying lengths, i.e., collection circuits of varying lengths. For example, these include a first line L1, a second line L2, a third line L3, a fourth line L4, and a fifth line L5. The first line L1 can be the line with the shortest wire 13 among the collection circuits of the flexible circuit board 1, and the second line L2 can be the line with the longest wire 13 among the collection circuits of the flexible circuit board 1. The maximum line resistance difference among the collection circuits of the flexible circuit board 1 can be understood as the difference between the maximum and minimum line resistances of the multiple wires 13.

[0042] The length of the wire 13 and the line width d of the wire 13 (eg Figure 3 (shown) meet:

[0043] The length of the conductor 13 is ≤ 0.5 m, and the line width d of the conductor 13 is 0.444 mm to 0.500 mm;

[0044] 0.5m<the length of the conductor 13≤1m, and the line width d of the conductor 13 is 0.889mm~1.000mm;

[0045] 1 m<the length of the conductive wire 13 ≤ 1.5 m, and the width of the conductive wire 13 is 1.333 mm to 1.500 mm.

[0046] Compared to the prior art solution in which the line width d of all wires is set to 0.5 mm, the above-described solution adjusts the line width d of wire 13 in the acquisition circuit. Specifically, for wires longer than 0.5 m, the line width d of wire 13 is increased to reduce the line resistance of wires longer than 0.5 m. By controlling the length and line width d of wire 13 to satisfy the aforementioned relationship, the line resistance of each acquisition circuit in the entire battery module is ≤ 850 mΩ, and the maximum line resistance difference in the acquisition circuit is ≤ 500 mΩ. This effectively reduces the line resistance variation of the acquisition circuits throughout the battery module, thereby effectively reducing the voltage drop in the acquisition circuits. At the same time, the width of the flexible circuit board 1 is ensured to meet the requirements of the battery module.

[0047] It should be noted that in this embodiment, the battery module refers to a rectangular battery module used in the automotive field. Line resistance can also be understood as impedance. The wire 13 may include copper, aluminum, silver, or gold wire, and the present invention does not specifically limit the cross-sectional shape of the wire 13.

[0048] Preferably, in some embodiments provided by the present invention, the conductor 13 is a copper wire. Compared with conductors 13 made of other materials, copper wire has more excellent comprehensive performance. This is mainly because copper wire has good electrical conductivity, which reduces the energy loss of the flexible circuit board 1 to a minimum when transmitting current and signals, ensuring the high efficiency and stability of the circuit. At the same time, the low resistivity of copper wire also means that it can carry a larger current under the same cross-sectional area, thereby improving the load capacity of the circuit; and the good ductility of copper wire enables the flexible circuit board 1 to maintain the continuity and integrity of the conductor during repeated bending and deformation, and is not prone to breakage, which greatly enhances the durability and reliability of the flexible circuit board 1; copper wire has excellent welding performance and is more firmly connected to electronic components, reducing the failure rate caused by poor welding and improving production efficiency. Production efficiency and product quality; the corrosion resistance of copper wire ensures the long-term stability of the wire in complex environments, is not easily damaged by moisture, chemicals, etc., and extends the service life of the flexible circuit board; the high thermal conductivity of copper wire helps to quickly conduct and disperse heat, prevent local overheating, protect electronic components, and improve the overall performance of the circuit; in addition, the processing precision of copper wire is high, which can meet the requirements of flexible circuit boards for fine lines and tiny apertures, and adapt to the trend of miniaturization and thinness of electronic equipment; in terms of cost-effectiveness, copper wire has a higher cost-effectiveness than other precious metal wires, reduces production costs, and makes flexible circuit boards 1 more competitive in the market.

[0049] In some other possible embodiments provided by the present invention, the length of the copper wire and the line width d of the copper wire satisfy:

[0050] The length of the copper wire is ≤0.5m, and the wire width d of the copper wire is 0.486mm~0.500mm;

[0051] 0.5m<copper wire length≤1m, copper wire width d is 0.970mm~1.000mm;

[0052] 1m<the length of the copper wire≤1.5m, and the wire width d of the copper wire is 1.458mm~1.500mm.

[0053] Therefore, the optimized configuration of the length and line width d of the copper wire ensures that each acquisition circuit has low line resistance under different length conditions, and the line resistance of each acquisition line is ≤500mΩ. For example, when the copper wire length is ≤0.5m, the line width d is controlled within the range of 0.486mm~0.500mm, which effectively reduces resistance, improves current transmission efficiency, avoids energy loss, and ensures stable operation of the circuit; secondly, as the length of the copper wire increases to 1m, the line width d is adjusted to 0.970mm~1.000mm accordingly, which not only maintains low line resistance, but also ensures the signal integrity of the wire 13 in longer distance transmission, reduces signal attenuation, and improves the overall performance of the circuit; further, when the copper wire length reaches 1.5m, the line width d is expanded to 1.458mm~1.500mm. The matching of line width d and length further optimizes the resistance characteristics of the wire 13, so that the circuit can still maintain high efficiency in longer distance transmission. At the same time, this design also improves the processing accuracy of the flexible circuit board 1, meets the requirements of high-density interconnection technology, enhances the bendability and durability of the circuit board, avoids the risk of wire breakage caused by mismatch of line width d, and improves product reliability. In addition, while ensuring that the wires 13 in the acquisition circuit have a small difference in line resistance, the width of the flexible circuit board 1 is effectively controlled, making the structure more compact.

[0054] Furthermore, in this embodiment, the flexible circuit board 1 also includes a plurality of buffer walls 14, spaced apart along its length. The nickel sheet 12 is at least partially located within the buffer walls 14. Specifically, one end of the nickel sheet 12 along its width lies within the buffer wall 14, where it connects to the wire 13 to form a joint. The joint is located within the buffer wall 14, which has a boss-like shape along its width. When the flexible circuit board 1 is deformed by external forces, the buffer wall 14 effectively reduces damage caused by the external forces, protecting the joint from damage, thereby improving the reliability and stability of the connection and extending the service life of the flexible circuit board 1. Furthermore, it ensures smooth current transmission, reduces energy loss, and improves overall circuit performance.

[0055] In some other possible embodiments provided by the present invention, continue to refer to Figure 2 As shown, the battery module further includes an aluminum busbar 2 and battery cells 3 , the aluminum busbar 2 and battery cells 3 are fixedly connected, and the nickel sheet 12 and the aluminum busbar 2 are fixedly connected.

[0056] In addition, in this embodiment, the wire 13 is fixedly connected to the nickel sheet 12 by welding, and the wire 13 is fixedly connected to the plug-in terminal 11 by welding. As a result, the wire 13 is fixedly connected to the nickel sheet 12 and the plug-in terminal 11 by welding, which further enhances the stability and reliability of the circuit. The welding connection also provides good electrical contact, reduces contact resistance, thereby reducing energy loss and improving the transmission efficiency of the circuit. The welding connection has high mechanical strength, making the connection between the wire 13 and the nickel sheet 12 and the plug-in terminal 11 more secure and less likely to loosen due to vibration or temperature changes, thereby ensuring the stable operation of the circuit in complex environments. The fixed connection by welding simplifies the assembly process, improves production efficiency, and reduces manufacturing costs.

[0057] In a second aspect, an embodiment of the present invention further discloses a battery pack, comprising a flexible circuit board of the battery module in any embodiment of the first aspect.

[0058] By adopting the above technical solution and providing the flexible circuit board as described above, the accuracy of the data collected by the battery pack is improved, and the safety performance of the battery pack is further improved.

[0059] In some other possible embodiments provided by the present invention, the battery pack also includes a battery management system, which is connected to the plug-in terminal, so that the data collected in the collection circuit is transmitted to the battery management system via the plug-in terminal. The battery management system is, for example, a BMS. In the above embodiment, the nickel sheet 12 is primarily used to collect voltage and current data from the battery cells 3 in the battery module. The voltage data is then transmitted to the plug-in terminal 11 via the wire 13, and then transmitted to the BMS via the plug-in terminal 11 for collection and reception. Due to the wire resistance of the wire 13, the voltage data collected by the BMS consists of the voltage data of the battery cells 3 and the voltage drop data of the wire 13. When the wire resistance of the wire 13 is too large or the line resistance of each collection line varies greatly, the voltage data collected by the BMS is too large, that is, the collection error is large. Through the configuration of the BMS, combined with the improvements of the above technical solutions, the difference in line resistance of the entire battery module collection line is effectively reduced, thereby effectively reducing the voltage drop of the collection line, thereby reducing the error of the cell voltage data collected by the BMS, improving the accuracy of the battery pack collection, and avoiding problems such as the BMS falsely reporting cell consistency due to excessive line resistance in the collection line. Among them, voltage drop is also called voltage or potential difference.

[0060] Specifically, when the battery module is working, the nickel sheet 12 collects the voltage and current data of the battery cell 3 in real time through the connection with the aluminum bus 2, obtains the voltage and current data of the battery module when it is working, and transmits the data to the BMS through the wire 13 and the plug terminal 11. The BMS monitors the battery module in real time based on the received data. When the monitored data differs greatly from the threshold parameters, the BMS will control the alarm and cut off the power if necessary, thereby ensuring the safety of the battery module.

[0061] The following will introduce it through more specific implementation methods.

[0062] Examples 1-5 and Comparative Example 1

[0063] Table 1 shows the performance data of Examples 1-5 and Comparative Example 1.

[0064] Table 1:

[0065]

[0066] Note: The conductor 13 in Examples 1-5 and Comparative Example 1 is a copper wire with a thickness of 35 microns and a resistivity of 0.017 Ω.mm. 2 / m (@20°C), the acquisition line current I is 2 mA. The line resistance calculation formula is: R = ρ × L / S, where ρ is the resistivity of wire 13, L is the length of wire 13, and A is the cross-sectional area of wire 13. The voltage drop calculation formula is: U = IR, where I is the acquisition line current and R is the line resistance of wire 13.

[0067] As can be seen from Table 1, in Examples 1-5, when wire 13 is copper, the line resistance of the different data acquisition lines is ≤ 500 mΩ, the maximum line resistance difference is 369.82 mΩ, and the maximum voltage drop is 0.74 mV. Compared with Example 5, Comparative Example 1 has much greater line resistance and voltage drop than Example 5 under the same wire 13 length, seriously affecting the accuracy of BMS data acquisition.

[0068] In summary, the present invention adjusts the line width d of the wires 13 of different lengths to achieve the maximum line resistance difference of different acquisition lines of the battery module to be controlled within 500mΩ, which can effectively reduce the line resistance difference between the lines, thereby effectively reducing the voltage drop of the acquisition line, reducing the error of the cell voltage data collected by the BMS, and avoiding problems such as BMS falsely reporting cell consistency due to excessive line resistance of the acquisition line.

[0069] Although the present invention has been illustrated and described with reference to certain preferred embodiments of the present invention, it should be understood by those skilled in the art that the above description is provided to further illustrate the present invention in conjunction with specific embodiments, and that the present invention should not be construed as being limited to these descriptions. Those skilled in the art may make various changes in form and detail, including simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A flexible circuit board for a battery module, characterized in that: include: A plug-in terminal is located at one end of the flexible circuit board in the length direction; Nickel sheets, wherein the nickel sheets are provided in plurality and the plurality of nickel sheets are spaced apart along the length direction; Wires, each of the nickel sheets is independently connected to the plug-in terminals via the wires; The length and width of the wire satisfy: The length of the wire is ≤0.5m, and the wire width is 0.444mm~0.500mm; 0.5m<the length of the wire≤1m, and the wire width of the wire is 0.889mm~1.000mm; 1m<the length of the conductive wire≤1.5m, and the wire width of the conductive wire is 1.333mm~1.500mm.

2. The flexible circuit board of the battery module according to claim 1, wherein: The conducting wire is a copper wire.

3. The flexible circuit board of the battery module according to claim 2, wherein: The length and width of the copper wire satisfy: The length of the copper wire is ≤0.5m, and the width of the copper wire is 0.486mm-0.500mm; 0.5m<the length of the copper wire≤1m, and the width of the copper wire is 0.970mm~1.000mm; 1m<the length of the copper wire≤1.5m, and the width of the copper wire is 1.458mm~1.500mm.

4. The flexible circuit board of the battery module according to claim 1, wherein: It also includes a buffer wall, which has multiple buffer walls and is arranged at intervals along the length direction. The nickel sheet is at least partially located on the buffer wall.

5. The flexible circuit board of the battery module according to claim 1, wherein: The wire is fixedly connected to the plug terminal by welding.

6. The flexible circuit board of the battery module according to claim 1, wherein: The battery module further includes an aluminum busbar and a battery cell, wherein the aluminum busbar and the battery cell are fixedly connected.

7. The flexible circuit board of the battery module according to claim 6, wherein: The nickel sheet and the aluminum bar are fixedly connected.

8. The flexible circuit board of the battery module according to claim 1, wherein: The wire is fixedly connected to the nickel sheet by welding.

9. A battery pack comprising the flexible circuit board of the battery module according to any one of claims 1 to 8.

10. The battery pack according to claim 9, wherein: A battery management system is also included, and the battery management system is connected to the plug terminal.

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