Battery module assembly method

Abstract

The invention provides a battery module assembly method, which is used for assembling a battery connection assembly CCS and a battery pack together, and comprises the following steps: laying an insulation isolation layer on a battery electrode above the battery pack; placing the CCS above the insulating isolation layer; the insulation isolation layer is pulled to move towards the first end or the second end by a unit step length, 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 far smaller than the length between the first end and the second end on the circuit board; welding a contact electrode and a battery electrode which are in contact in a unit step length; and the steps are circulated and alternated until the insulation isolation layer is completely pulled out of the battery pack, and all the contact electrodes and the corresponding battery electrodes are welded together. According to the assembling method, the single batteries are gradually connected into the CCS, so that the occurrence of surge current can be effectively avoided, the impact on the control panel is reduced, and the assembling yield and reliability of the battery module 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, have put forward higher requirements for their safety, reliability and cost control. Among them, in the existing battery module assembly process, it is usually necessary to arrange the battery connection assembly (CCS) on each single battery electrode on the battery pack, and then connect these electrodes by welding. However, this traditional assembly method has the problem of high-voltage hot plug damage, which has a negative impact on the assembly yield of the battery module.

[0003] Specifically, when the operator places the CCS on top of the battery pack, the electrodes of multiple single cells often come into instantaneous contact with the connection electrodes on the CCS at the same time. Although the formal welding operation has not yet been carried out, this instantaneous contact will form an instantaneous current path, thereby generating a large current on the CCS, the so-called surge current.

[0004] The rapid appearance and disappearance of this surge current will cause great impact on the electronic control components in the battery module, especially the control board connected to the CCS. These impacts may cause a series of problems, including but not limited to the burning of the control board, damage to circuit components, and temporary failure of electronic components. These problems will not only reduce the service life of the control board, but also directly affect 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 which can effectively avoid high voltage hot plug damage during the battery module assembly process.

[0006] In order to achieve the above-mentioned object, the present invention provides a battery module assembly method, which is used to assemble a battery connection assembly CCS with a battery pack, wherein the battery pack includes a plurality of rechargeable single batteries, and the CCS includes a supporting base plate and a plurality of contact electrodes and a circuit board arranged on the supporting base plate, wherein the contact electrodes are electrically connected to the circuit board through a connector, and the plurality of contact electrodes are arranged at intervals from a first end to a second end of the circuit board, and the first end and the second end are opposite to each other; the assembly method comprises:

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

[0008] Placing the CCS above 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] Pull the insulating isolation layer to move 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 electrode above, and 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 first end and the second end direction 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 arranged 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 working status of each single cell 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 three: A mixed structure with part of it being FPC cable and part being PCB board.

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

[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 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 arranged 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 of the battery packs, and two communication connectors are provided on each of the circuit boards. A pair of the 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.

[0024] Compared with the prior art, the battery module assembly method provided by the above technical solution of the present invention, before placing the CCS on the battery pack, first covers the battery electrodes in the battery pack with an insulating isolation layer, and then uses a cyclic alternating method to extract and weld the insulating isolation layer until the insulating isolation layer is completely extracted, and all contact electrodes are welded together with the corresponding battery electrodes. It can be seen that the above assembly method, because the single battery is gradually connected to the CCS, can effectively avoid the occurrence of surge current, reduce the impact on the control board, and thus improve 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 4 is a planar structural diagram of a battery pack in an embodiment of the present invention.

[0027] Figure 3 FIG. 4 is an exploded view of a CCS in an embodiment of the present invention.

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

[0029] Figure 5a to Figure 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 in 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 in another embodiment of the present invention.

[0032] Figure 8 The figure is a structural diagram of a battery management system in 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 implementation methods and the accompanying drawings.

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

[0035] The CCS includes a supporting base plate 10, a plurality of contact electrodes J1 disposed on the supporting base plate 10, and a circuit board 11. The contact electrodes J1 are electrically connected to the circuit board 11 through a connector 12. The plurality of contact electrodes J1 are arranged at intervals from a first end D1 to a second end D2 of the circuit board 11, and the first end D1 and the second end D2 are opposite. The assembly method in this embodiment mainly refers to the process of welding the contact electrodes J1 to the battery electrodes J2 on the battery pack PA. To this end, the assembly method includes:

[0036] S1: 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, and make each contact electrode J1 on the CCS directly opposite to each battery electrode J2 in the battery pack PA.

[0038] S3: Figure 5c , pull the insulating isolation layer 4 toward the second end D2 (or the 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, and 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 more than three times of L1, it can be considered that L1 is much smaller than L2.

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

[0040] S5: Execute steps S3 and S4 in this way in a loop. 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 (eg 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 and CCS of the first end D1 are welded together. After the second movement, the second single cell CE and CCS of the first end D1 are welded together. This process is repeated until the last single cell CE and CCS are welded together.

[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 4 is provided at the second end D2 of the battery pack PA. Figure 5b to Figure 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 4. The winding device 4 drives the insulating film to be gradually withdrawn from the battery pack PA in an intermittent manner. In this embodiment, the winding device 4 is used to drive the insulating film to be gradually withdrawn at intervals, which effectively improves 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 through a communication signal line. The analog front-end circuit AFE is used to collect working parameter data and control the working status of each single battery CE in the battery pack PA.

[0046] In this embodiment, compared with the traditional battery management system, 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 CCS, so that the analog front-end circuit AFE directly collects working parameter data and controls the working state 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 ), thereby effectively reducing the cost of wiring harnesses and hardware; secondly, due to the simplified line design, the line impedance between the single cell CE and the analog front-end circuit AFE is reduced, which is conducive to increasing the balancing current, for example, increasing the balancing current from 100mA to 300mA; furthermore, the CCS with the above structure saves the control board BCU and the adapter harness X2 for the supply chain of the manufacturer, thereby effectively shortening the supply chain and simplifying the supply chain management. In addition, since there is no need to plug and unplug the adapter cable, it is easier to realize automated production and improve 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 three: A mixed structure with part of it being FPC cable and part being PCB board.

[0052] On the other hand, the connecting member 12 includes a conductive nickel sheet. The end of the conductive nickel sheet extending out of the circuit board 11 can be welded to the contact electrode J1 by laser welding or ultrasonic welding technology.

[0053] On the other hand, the analog front-end circuit AFE 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 signal and the current signal of the single cell CE respectively. The temperature acquisition circuit is used to acquire the temperature of the single cell 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 arranged 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, so that the temperature distribution of the battery pack PA can be more comprehensively and accurately understood.

[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 actual applications, it is generally impossible 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, the 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 direction, the circuit board 11 is located in the wire groove 100, and a plurality of positioning grooves 101 are arranged at intervals on both sides of the wire groove 100 along the long axis direction. The contact electrode J1 is located in the positioning groove 101, and a through hole 102 is also arranged in the positioning groove 101. The contact electrode J1 includes an edge portion J10 and a contact portion J11, and 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 the 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 through 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) via 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 rights 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 covered by 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 comprises a plurality of rechargeable single cells, characterized in that: The CCS comprises a supporting base plate, a plurality of contact electrodes arranged on the supporting base plate, and a circuit board, wherein the contact electrodes are electrically connected to the circuit board through a connector, and the plurality of contact electrodes are arranged at intervals from a first end to a second end of the circuit board, and the first end is opposite to the second end; the assembly method comprises: Laying an insulating isolation layer on the battery electrodes above the battery pack; Placing the CCS above 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; Pull the insulating isolation layer to move 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 electrode 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 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 first end and the second end direction 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 1, characterized in that: When the insulating film is used as the insulating isolation layer, a winding device is arranged 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 working parameter data and control working 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 three: A mixed structure with part of it 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 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 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 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 arranged 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.

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. Two communication connectors are provided on each circuit board. 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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