Battery module assembly method

Abstract

The application provides a battery module assembly method for assembling a battery connection component (CCS) and a battery pack, which comprises: laying an insulating isolation layer on the battery electrodes above the battery pack; placing the CCS above the insulating isolation layer; pulling the insulating isolation layer to move a unit step length to the first end or the second end, so that one or more battery electrodes in the unit step length are in contact with the corresponding contact electrodes above, and the unit step length is much smaller than the length between the first end and the second end on the circuit board; welding the contact electrodes and the battery electrodes in contact in the unit step length; and repeating the above steps until the insulating isolation layer is completely pulled out of the battery pack and all the contact electrodes are welded with the corresponding battery electrodes. For the above assembly method, since the single battery is gradually connected to the CCS, the occurrence of inrush current can be effectively avoided, the impact on the control board is reduced, and the yield and reliability of the battery module assembly are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery modules, and in particular to a battery module assembly method. Background Art

[0002] With the rapid development of the electric vehicle industry, power battery modules, as one of the core components of electric vehicles, are facing higher requirements for safety, reliability, and cost control. In the existing battery module assembly process, the battery connection assembly (CCS) is typically placed on the individual battery electrodes in the battery pack and then connected by welding. However, this traditional assembly method is subject to damage from high-voltage hot-plugging, which negatively impacts the assembly yield of the battery module.

[0003] Specifically, when workers place the CCS on top of the battery pack, the electrodes of multiple individual cells often come into instantaneous contact with the connection electrodes on the CCS. Although the actual welding operation has not yet taken place, this momentary contact creates a transient current path, generating a large current in the CCS, known as surge current.

[0004] The rapid onset and disappearance of this surge current can severely impact the electronic control components within the battery module, particularly the control board connected to the CCS. These impacts can cause a range of problems, including but not limited to burning out the control board, damaging circuit components, and temporarily malfunctioning electronic components. These issues not only shorten the lifespan of the control board but also directly impact the quality and assembly success rate of the entire battery module. Summary of the Invention

[0005] The object of the present invention is to provide a battery module assembly method that effectively avoids high-voltage hot plug damage during the battery module assembly process.

[0006] To achieve the above objectives, the present invention provides a battery module assembly method for assembling a battery connection assembly (CCS) with a battery pack, wherein the battery pack includes a plurality of rechargeable single cells, and the CCS includes a support base plate, a plurality of contact electrodes disposed on the support base plate, and a circuit board, wherein the contact electrodes are electrically connected to the circuit board via connectors, and the plurality of contact electrodes are spaced apart from a first end to a second end of the circuit board, with the first end and the second end facing each other. The assembly method comprises:

[0007] Laying an insulating isolation layer on the battery electrodes above the battery pack;

[0008] Placing the CCS on top of the insulating isolation layer so that each of the contact electrodes on the CCS is directly opposite to each of the battery electrodes in the battery pack;

[0009] Pulling the insulating isolation layer toward the first end or the second end by a unit step length so that one or more battery electrodes within the unit step length contact the corresponding contact electrodes above, wherein the unit step length is much smaller than the length between the first end and the second end on the circuit board;

[0010] welding the contact electrodes and the battery electrodes that are in contact within the unit step length together;

[0011] This cycle is repeated until the insulating isolation layer is completely pulled out of the battery pack and all contact electrodes are welded to the corresponding battery electrodes.

[0012] Preferably, the unit step length is the same as the spacing distance between two adjacent contact electrodes in the direction of the first end and the second end of the circuit board.

[0013] Preferably, the insulating isolation layer includes any one of a flexible insulating film and a rigid insulating plate.

[0014] Preferably, when the insulating film is used as the insulating isolation layer, a winding device is provided at the second end of the battery pack, one end of the insulating film is laid on the battery electrode of the battery pack, and the other end of the insulating film is connected to the winding wheel of the winding device, and the insulating film is driven by the winding device to be gradually pulled out from the battery pack in an intermittent manner.

[0015] Preferably, an analog front-end circuit is integrated on the circuit board, and the analog front-end circuit is communicatively connected to a main control board located outside the CCS via a communication signal line. The analog front-end circuit is used to collect working parameter data and control the working status of each single battery in the battery pack.

[0016] Preferably, the substrate of the circuit board is any of the following structures:

[0017] Structure 1: The whole is FPC cable;

[0018] Structure 2: The whole is PCB board;

[0019] Structure 3: A hybrid structure with part being FPC cable and part being PCB board.

[0020] Preferably, the analog front-end circuit includes a plurality of temperature sensors for respectively collecting the temperature of each of the single cells. The temperature sensors are arranged at each location on the circuit board connected to the connector. The temperature sensors collect the temperature of the single cells through the connector and the contact electrodes.

[0021] Preferably, the analog front-end circuit and the circuit board share a ground terminal located on the surface of the circuit board.

[0022] Preferably, the supporting base plate includes a wire groove extending along its long axis direction, the circuit board is located in the wire groove, and a plurality of positioning grooves are provided on both sides of the wire groove at intervals along the extension direction from the first end to the second end. The contact electrode is located in the positioning groove, and a through hole is also provided in the positioning groove. The contact electrode includes an edge portion and a contact portion, and the contact portion abuts against the electrode of the single cell through the through hole.

[0023] Preferably, the battery module includes multiple battery packs and multiple CCSs corresponding to each battery pack. Each circuit board is provided with two communication connectors. A pair of communication connectors between two adjacent CCSs are connected by a signal line, so that the analog front-end circuits on the multiple CCSs in the battery module are communicated with the main control board through the same communication line.

[0024] Compared to the prior art, the battery module assembly method provided by the above technical solution of the present invention first covers the battery electrodes within the battery pack with an insulating barrier before placing the CCS on the battery pack. The insulating barrier is then removed and welded in a cyclical, alternating manner until the insulating barrier is completely removed and all contact electrodes are welded to the corresponding battery electrodes. This assembly method, by gradually connecting individual cells to the CCS, effectively avoids surge currents and reduces impact on the control board, thereby improving the yield and reliability of battery module assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1a and Figure 1b They are respectively the front and back planar structural diagrams of the CCS in an embodiment of the present invention.

[0026] Figure 2 2 is a planar structural diagram of a battery pack in an embodiment of the present invention.

[0027] Figure 3 FIG. 1 is an exploded view of a CCS according to an embodiment of the present invention.

[0028] Figure 4 for Figure 1a Enlarged view of part A in the middle.

[0029] Figures 5a to 5d Schematic diagram of the battery module assembly process in an embodiment of the present invention.

[0030] Figure 6 FIG. 1 is a planar connection diagram of a battery management system within a battery module according to one embodiment of the present invention.

[0031] Figure 7 FIG. 1 is a connection diagram of a battery management system in a battery module according to another embodiment of the present invention.

[0032] Figure 8 This is a structural diagram of a battery management system within a battery module in the prior art. DETAILED DESCRIPTION

[0033] In order to explain the technical content, structural features, achieved objectives and effects of the present invention in detail, the following is a detailed description in conjunction with the embodiments and the accompanying drawings.

[0034] This embodiment discloses a battery module assembly method, such as Figures 1a to 3 , used to assemble the battery connection component CCS and the battery pack PA together, and realize lossless high-voltage hot-swap assembly, so as to achieve the purpose of improving the battery module assembly yield.

[0035] The CCS includes a support base plate 10, a plurality of contact electrodes J1 disposed on the support base plate 10, and a circuit board 11. The contact electrodes J1 are electrically connected to the circuit board 11 via connectors 12. The plurality of contact electrodes J1 are spaced apart from each other from a first end D1 to a second end D2 of the circuit board 11, with the first end D1 and the second end D2 facing each other. The assembly method in this embodiment primarily involves welding the contact electrodes J1 to the battery electrodes J2 on the battery pack PA. The assembly method includes the following steps:

[0036] S1: If Figure 5a and Figure 5b , an insulating isolation layer 4 is laid on the battery electrode J2 above the battery pack PA.

[0037] S2: Place the CCS on top of the insulating isolation layer 4 so that the contact electrodes J1 on the CCS are directly opposite to the battery electrodes J2 in the battery pack PA.

[0038] S3: If Figure 5c , the insulating isolation layer 4 is pulled toward the second end D2 (or first end D1) by a unit step length, so that one or more battery electrodes J2 within the unit step length contact the corresponding contact electrode J1 above. The unit step length L1 is much smaller than the length L2 between the first end D1 and the second end D2 on the circuit board 11. It should be noted that as long as the length of L2 is at least three times that of L1, L1 can be considered much smaller than L2.

[0039] S4: Welding together the contact electrode J1 and the battery electrode J2 that are in contact within the unit step.

[0040] S5: Execute steps S3 and S4 in this cycle, such as Figure 5d, until the insulating isolation layer 4 is completely pulled out of the battery pack PA, and all contact electrodes J1 are welded together with the corresponding battery electrodes J2.

[0041] On the other hand, the unit step length is equal to the spacing distance d between two adjacent contact electrodes J1 in the direction of the first end D1 and the second end D2 on the circuit board 11 (e.g. Figure 1b ) are the same, so that each time the insulating isolation layer 4 is moved, a minimum number of contact electrodes J1 are welded to the battery electrodes J2, that is, each time the insulating isolation layer 4 is moved, a single battery CE is welded to the CCS, so that the voltage on the CCS increases with a smaller amplitude.

[0042] like Figure 5b and 5c After the insulating isolation layer 4 moves toward the second end D2 for the first time, the first single cell CE at the first end D1 is welded to the CCS. After the second movement, the second single cell CE at the first end D1 is welded to the CCS. This process continues until the last single cell CE is welded to the CCS.

[0043] On the other hand, the insulating isolation layer 4 includes any one of a flexible insulating film and a rigid insulating plate.

[0044] When an insulating film is used as the insulating isolation layer 4, a winding device 5 is provided at the second end D2 of the battery pack PA. Figures 5b to 5d One end of the insulating film is laid on the battery electrode J2 of the battery pack PA, and the other end of the insulating film is connected to the winding wheel of the winding device 5. The winding device 5 drives the insulating film to be gradually and intermittently removed from the battery pack PA. In this embodiment, the winding device 5 drives the gradual and interval removal of the insulating film, effectively improving the degree of automation.

[0045] On the other hand, as shown in Figure 1, Figure 4 An analog front-end circuit AFE is integrated on the circuit board 11. The analog front-end circuit AFE is connected to the main control board outside the CCS via a communication signal line. The analog front-end circuit AFE is used to collect operating parameter data and control the operating status of each single battery CE in the battery pack PA.

[0046] In this embodiment, compared with the traditional battery management system, the CCS not only has the function of signal connection and transmission, but also integrates functional circuits, that is, the analog front-end circuit AFE is integrated into the CCS. In this way, the analog front-end circuit AFE directly collects working parameter data and controls the working status of each single battery CE through the circuit board 11. The analog front-end circuit AFE only needs to communicate with the main control board through the communication signal line (such as Figure 6 ).

[0047] Therefore, the battery module eliminates the independent slave control board BCU and the adapter harness X1 for analog signal transmission (such as Figure 8 ), effectively reducing wiring harness and hardware costs. Secondly, the simplified circuit design reduces the line impedance between the single cell CE and the analog front-end circuit AFE, which helps increase the balancing current, for example, from 100mA to 300mA. Furthermore, for the manufacturer's supply chain, the CCS using the above structure eliminates the need for the slave control board BCU and adapter harness X2, effectively shortening the supply chain and simplifying supply chain management. Furthermore, since the adapter cable does not need to be plugged in or out, it facilitates automated production and improves production efficiency.

[0048] On the other hand, the substrate of the circuit board 11 can be any of the following structures:

[0049] Structure 1: The whole is FPC cable;

[0050] Structure 2: The whole is PCB board;

[0051] Structure 3: A hybrid structure with part being FPC cable and part being PCB board.

[0052] On the other hand, the connecting member 12 comprises a conductive nickel sheet. Laser welding or ultrasonic welding can be used to weld one end of the conductive nickel sheet extending out of the circuit board 11 to the contact electrode J1.

[0053] The analog front-end (AFE) circuit includes a voltage acquisition circuit, a current acquisition circuit, and a temperature acquisition circuit. The voltage acquisition circuit and the current acquisition circuit are used to acquire the voltage and current signals of the individual cells CE, respectively. The temperature acquisition circuit is used to acquire the temperature of the individual cells CE.

[0054] The temperature acquisition circuit in this embodiment includes a plurality of temperature sensors T for respectively acquiring the temperature of each single cell CE. The temperature sensor T is provided at each location on the circuit board 11 connected to the connector 12. The temperature sensor T acquires the temperature of the single cell CE through the connector 12 and the contact electrode J1.

[0055] In this embodiment, a temperature sensor T is configured for each single cell CE to achieve full sampling and monitoring of the temperatures of all single cells CE, thereby enabling a more comprehensive and accurate understanding of the temperature distribution of the battery pack PA.

[0056] In the traditional BMS architecture, since the CCS needs to be connected to the slave control board BCU through the analog signal adapter harness X2, when the number of single cells CE in a battery pack PA is relatively large, if a temperature sensor T is configured for each single cell CE, the volume of the analog signal adapter harness X1 will be greatly increased. Therefore, in practical applications, it is generally not possible to configure a temperature sensor T for each single cell CE.

[0057] On the other hand, the analog front-end circuit AFE and the circuit board 11 share a ground terminal located on the surface of the circuit board 11. In this way, the ground loop area can be reduced, electromagnetic interference can be reduced, and the quality of signal transmission can be improved.

[0058] On the other hand, Figure 3 The supporting base plate 10 includes a wire groove 100 extending along its long axis. The circuit board 11 is located in the wire groove 100. A number of positioning grooves 101 are arranged at intervals along the long axis on both sides of the wire groove 100. The contact electrode J1 is located in the positioning groove 101. A through hole 102 is also provided in the positioning groove 101. The contact electrode J1 includes an edge portion J10 and a contact portion J11. The contact portion J11 abuts against the battery electrode J2 of the single battery CE through the through hole 102.

[0059] Through the structure of the supporting base plate 10 in this embodiment, the contact electrodes J1 can be distributed on both sides of the circuit board 11 to effectively improve space utilization.

[0060] On the other hand, Figure 6 The battery module includes multiple battery packs PA and multiple CCSs corresponding to each battery pack PA. Two communication connectors 3 are provided on each circuit board 11. A pair of communication connectors 3 between two adjacent CCSs are connected by a communication signal line, so that the analog front-end circuits AFE on multiple CCSs in the battery module are communicated with the main control board through the same communication line.

[0061] In addition, if Figure 7 Each circuit board 11 can also be directly connected to the loop of a communication bus (such as a CAN bus) through two communication connectors 3.

[0062] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope of the present invention.

Claims

1. A battery module assembly method for assembling a battery connection assembly (CCS) with a battery pack, wherein the battery pack includes a plurality of rechargeable single cells, characterized in that: The CCS includes a supporting base plate, a plurality of contact electrodes disposed on the supporting base plate, and a circuit board, wherein the contact electrodes are electrically connected to the circuit board via connectors, and the plurality of contact electrodes are spaced apart from a first end to a second end of the circuit board, with the first end and the second end facing each other. The assembly method includes: Laying an insulating isolation layer on the battery electrodes above the battery pack; Placing the CCS on top of the insulating isolation layer so that each of the contact electrodes on the CCS is directly opposite to each of the battery electrodes in the battery pack; Pulling the insulating isolation layer toward the first end or the second end by a unit step length so that one or more battery electrodes within the unit step length contact the corresponding contact electrodes above, and the length between the first end and the second end on the circuit board is more than three times the unit step length; welding the contact electrodes and the battery electrodes that are in contact within the unit step length together; This cycle is repeated until the insulating isolation layer is completely pulled out of the battery pack and all contact electrodes are welded to the corresponding battery electrodes.

2. The battery module assembly method according to claim 1, characterized in that: The unit step length is the same as the spacing distance between two adjacent contact electrodes in the direction of the first end and the second end of the circuit board.

3. The battery module assembly method according to claim 1, characterized in that: The insulating isolation layer includes any one of a flexible insulating film and a rigid insulating plate.

4. The battery module assembly method according to claim 3, characterized in that: When the insulating film is used as the insulating isolation layer, a winding device is provided at the second end of the battery pack, one end of the insulating film is laid on the battery electrode of the battery pack, and the other end of the insulating film is connected to the winding wheel of the winding device. The winding device drives the insulating film to be gradually pulled out from the battery pack in an intermittent manner.

5. The battery module assembly method according to claim 1, characterized in that: An analog front-end circuit is integrated on the circuit board. The analog front-end circuit is communicatively connected to a main control board located outside the CCS via a communication signal line. The analog front-end circuit is used to collect operating parameter data and control the operating status of each single battery in the battery pack.

6. The battery module assembly method according to claim 5, characterized in that: The substrate of the circuit board is any of the following structures: Structure 1: The whole is FPC cable; Structure 2: The whole is PCB board; Structure 3: A hybrid structure with part being FPC cable and part being PCB board.

7. The battery module assembly method according to claim 5, characterized in that: The analog front-end circuit includes several temperature sensors for respectively collecting the temperature of each single cell. The temperature sensors are arranged at each location on the circuit board connected to the connector. The temperature sensors collect the temperature of the single cell through the connector and the contact electrode.

8. The battery module assembly method according to claim 5, characterized in that: The analog front-end circuit and the circuit board share a ground terminal located on the surface of the circuit board.

9. The battery module assembly method according to claim 5, characterized in that: The supporting base plate includes a wire groove extending along its long axis direction, the circuit board is located in the wire groove, and a plurality of positioning grooves are respectively arranged at intervals on both sides of the wire groove along the extension direction from the first end to the second end. The contact electrode is located in the positioning groove, and a through hole is also provided in the positioning groove. The contact electrode includes an edge portion and a contact portion, and the contact portion abuts against the electrode of the single battery through the through hole.

10. The battery module assembly method according to claim 5, characterized in that: The battery module includes multiple battery packs and multiple CCSs corresponding to each battery pack. Each circuit board is provided with two communication connectors. A pair of communication connectors between two adjacent CCSs are connected by signal lines, so that the analog front-end circuits on the multiple CCSs in the battery module are communicated with the main control board through the same communication line.

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