Integrated battery pack safety detection apparatus and manufacturing process therefor

Abstract

Disclosed in the present invention are an integrated battery pack safety detection apparatus and a detection method. The detection apparatus comprises: a plurality of PCB control boards, the PCB control boards being provided with a plurality of detection slots; detection blocks accommodated in the detection slots, a first side of each detection block being connected to a hard first micro-connection structure, detection legs being arranged on the first micro-connection structures, a second side of each detection block being connected to a flexible and deformable second micro-connection structure, and detection lines being densely distributed on the back surfaces of the detection blocks; a metal busbar, the metal busbar comprising a plurality of aluminum bars; and conductive connectors, each conductive connector comprising an FPC connection body and a conductive sheet, the conductive sheet being provided with a temperature sensor. The present invention achieves combination of various detection modes, can effectively detect the state of battery packs in the early stage of thermal runaway and improve the accuracy and referability of detection, and can further ensure the stable connection between the aluminum bars and the PCB control boards, thereby maintaining the effectiveness of the detection apparatus.

Description

Integrated battery pack safety testing device and its processing technology Technical Field

[0001] This invention relates to the field of battery pack technology, and in particular to an integrated battery pack safety detection device and its processing technology. Background Technology

[0002] With the rapid development of energy storage technology, batteries are being used more and more widely, thus placing increasingly higher demands on battery safety and reliability. During battery use, problems such as severe overcharging, short circuits, severe overheating, thermal runaway, impact or crushing deformation, and punctures can occur. These problems may cause the internal temperature and pressure of the battery to rise continuously, and when they exceed its inherent safety threshold, the battery may explode.

[0003] The battery safety valve is the last line of defense against explosions. When the internal pressure of the battery reaches the valve's opening threshold (for example, the opening threshold for a lithium-ion battery safety valve is typically 600–800 kPa), the safety valve opens to release pressure and prevent an explosion. However, when the battery safety valve is open, it indicates a serious safety problem. Therefore, it is necessary to check the safety valve when it is open to prevent the accident from escalating.

[0004] Currently, the safety valve is usually determined to be open by detecting the electrolyte splashed out when it is opened. However, the direction of electrolyte splashing is uncertain, and there is a certain lag after the electrolyte splashes onto the sensor before detection, which affects the detection effect. At the same time, the detection circuit board and the battery cell are usually connected by hard nickel sheets, which can become loose or deformed due to mechanical vibration during transportation or handling, causing the detection circuit board to fail due to poor contact or power failure. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide an integrated battery pack safety testing device and testing method, which has the advantages of improving the testing effect and maintaining the testing effectiveness.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] According to a first aspect of the present disclosure, an integrated battery pack safety detection device is provided, comprising:

[0008] Several PCB control boards are used for communication connection with the BMS system. The PCB control boards are provided with several detection slots corresponding to the safety valves of each battery cell. The PCB control boards are fixed to the top of the battery pack and form a predetermined distance between them and the safety valves.

[0009] A detection block is housed within each of the aforementioned detection slots. A rigid first micro-connection structure connects the first side of the detection block to the PCB control board, allowing the detection block to be suspended within the detection slot. Detection feet are arranged on the first micro-connection structure. The detection block can withstand the impact force of the safety valve opening, causing the first micro-connection structure and detection feet to break and form a first detection signal. A second micro-connection structure is connected to the PCB control board on the second side of the detection block, opposite to the first side. The second micro-connection structure is flexible and deformable, and can maintain its connection state when subjected to impact force. The back of the detection block is densely covered with detection lines connected to a second detection circuit, used to change the parallel detection resistance value of the second detection circuit to form a second detection signal when in contact with electrolyte.

[0010] A busbar, comprising a plurality of aluminum plates respectively configured to correspond to the positive / negative terminals of each battery cell to achieve series connection of each individual battery cell; and,

[0011] Several conductive connectors are respectively connected between each aluminum bar and the PCB control board. The conductive connectors include: an FPC connection body electrically connected to the PCB control board, and a conductive sheet for realizing the conductive connection between the FPC connection body and the corresponding aluminum bar. The conductive sheet is provided with a temperature sensor to directly collect the temperature information of the corresponding aluminum bar.

[0012] In some exemplary embodiments, a base plate is fixed on the top of the battery pack. The base plate is provided with a plurality of fixing slots adapted to the PCB control board and a plurality of positioning slots adapted to the aluminum foil. The PCB control board is embedded in the fixing slots to form a predetermined distance between it and the safety valves, and the fixing slots are provided with openings corresponding to each safety valve.

[0013] In some exemplary embodiments, the first micro-connection structure includes two separately arranged connection pins, and the detection circuit includes a first pin and a second pin respectively arranged on the two connection pins. The first pin and the second pin are connected to a first detection circuit. When the first pin and / or the second circuit is broken, the resistance value of the first detection circuit is changed to form a first detection signal.

[0014] In some exemplary embodiments, the detection circuit includes a first circuit and a second circuit, wherein the first circuit and the second circuit are close to each other but do not touch each other;

[0015] The first line includes a first main line and multiple first branch lines connected to the first main line. The second line includes a second main line and multiple second branch lines connected to the second main line. The first main line basically surrounds the second line and forms a detection area. The first branch lines are located inside the first main line, and each first branch line and each second branch line are arranged alternately and sequentially. The first branch lines and second branch lines are densely distributed in the detection area. The second main line is located in the middle of the detection area, and the second branch lines are located on both sides of the second main line.

[0016] In some exemplary embodiments, a first terminal is formed at one end of the first main line, and a second terminal is formed by extending the first main line out of the first main line. The first terminal and the second terminal are connected to the second detection circuit. When the detection area comes into contact with electrolyte, the resistance between the first line and the second line changes to change the parallel detection resistance value of the second detection circuit to form a second detection signal.

[0017] In some exemplary embodiments, the first side of the FPC connection body is provided with a connection pad for electrical connection with the PCB control board, and the second side is formed with a connection ear for electrical connection with a conductive sheet. The first end of the conductive sheet is electrically connected to the connection ear, and the second end is electrically connected to the aluminum foil.

[0018] In some exemplary embodiments, the conductive sheet is arranged along an extension direction perpendicular to the PCB control board;

[0019] Alternatively, the connecting tabs extend outward from the second side of the FPC connecting body, and the conductive sheets are arranged along an extension direction parallel to the PCB control board.

[0020] According to a second aspect of the present disclosure, a method for processing an integrated battery pack safety detection device as described in the first aspect is provided, comprising:

[0021] Take a PCB substrate of appropriate size, and perform groove processing on the PCB substrate according to the predetermined process dimensions to form a number of detection slots, and form a detection block and a first micro-connection structure corresponding to each detection slot;

[0022] A second micro-connection structure is formed between the detection block and the PCB substrate using a lamination process;

[0023] A PCB control board is formed by printing a first detection circuit and a second detection circuit on the PCB substrate and printing detection lines on each detection block. The first micro-connection structure has detection pins connected to the first detection circuit, and the second detection circuit is connected to the detection lines through the second micro-connection structure.

[0024] A pre-formed substrate is fixed on the top of the battery pack, and aluminum foil is sequentially inserted into the positioning groove on the substrate to form a busbar to connect each individual cell in series.

[0025] After the prepared PCB control board is embedded into the fixing groove on the substrate, the first side of multiple pre-made conductive connectors is electrically connected to each preset soldering point on the PCB control board, and the second side is electrically connected to each aluminum bar sheet to form a detection device for communication connection with the BMS system.

[0026] In some exemplary embodiments, the method for preparing the conductive connector includes:

[0027] Conductive circuits are formed on the FPC substrate according to the predetermined process flow.

[0028] The FPC substrate is punched to form an FPC connector body, wherein the first side of the FPC connector body is provided with a connector pad for electrical connection with the PCB control board, and the second side is formed with a connector ear.

[0029] The pre-processed conductive sheet is welded and fixed to the connecting lug to form a conductive connection structure;

[0030] A temperature sensor is installed inside the conductive sheet to directly collect temperature information of the aluminum foil.

[0031] The conductive connection structure is soldered to a preset soldering point on the PCB control board via a connecting pad so that the conductive sheet is located on the outside of the PCB control board for electrical connection with the aluminum foil.

[0032] In some exemplary embodiments, when the FPC connector body is formed by punching, a deformation groove is formed between the connector pad and the connector lug, and a micro connector piece is formed on one side of the deformation groove.

[0033] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0034] This invention provides an integrated battery pack safety detection device and its manufacturing process. By directly absorbing the impact force through the detection block to detect the breakage of the first micro-connection structure and thus the valve opening, the detection is faster and significantly improves timeliness, providing a quicker response for subsequent signal processing and enhancing detection effectiveness. Simultaneously, through the second micro-connection structure and detection circuitry, leakage detection can be performed concurrently after the first micro-connection structure breaks. Combined with temperature detection from a temperature sensor, the thermal runaway situation can be further determined. The combination of multiple detection methods effectively detects the early stages of battery pack thermal runaway, improving accuracy and reliability. Furthermore, by setting the conductive connector as a combination of an FPC connector body and a conductive sheet, the FPC connector body, with its good tensile strength, can buffer mechanical vibrations during transportation, reducing deformation of the conductive connection structure and effectively improving overall tensile strength, flexibility, and extensibility. It also provides better vibration resistance, ensuring a stable connection between the aluminum plate and the PCB control board, maintaining the effectiveness of the detection device. Attached Figure Description

[0035] Figure 1 is a schematic diagram of the integrated battery pack safety detection device in an embodiment of the present invention.

[0036] Figure 2 is a perspective view of the integrated battery pack safety detection device in an embodiment of the present invention.

[0037] Figure 3 is a schematic diagram of the connection structure between the PCB control board and the conductive connector in an embodiment of the present invention.

[0038] Figure 4 is a schematic diagram of the structure of the PCB control board and the detection block in an embodiment of the present invention.

[0039] Figure 5 is a schematic diagram of the structure of the first detection circuit in an embodiment of the present invention.

[0040] Figure 6 is a schematic diagram of the structure of the second detection circuit in an embodiment of the present invention.

[0041] Figure 7 is a schematic diagram of the structure of the conductive connector in an embodiment of the present invention.

[0042] Figure 8 is a structural schematic diagram of a conductive connector according to another embodiment of the present invention.

[0043] Figure 9 is a schematic diagram of the connection structure between the PCB control board and the conductive connector according to another embodiment of the present invention.

[0044] The numbers and letters in the diagram represent the following components: 10, PCB control board; 11, detection slot; 20, detection block; 21, first micro-connection structure; 211, connecting pin; 22, detection pin; 221, first pin; 222, second pin; 30, second micro-connection structure; 40, detection circuit; 41, first circuit; 411, first main circuit; 412, first branch circuit; 413, first terminal; 42, second circuit; 421, second main circuit; 422, second branch circuit; 423, second terminal; 50, first detection circuit; 51, first detection resistor; 60, second detection circuit. 61. Second detection resistor; 70. Busbar; 71. Aluminum strip; 80. Conductive connector; 81. FPC connector body; 811. Connecting pad; 812. Connecting lug; 813. Deformation groove; 814. Micro connector; 82. Conductive sheet; 821. Temperature sensor; 822. Receiving groove; 823. Clip-on spring; 824. Welding groove; 90. Battery pack; 91. Substrate; 92. Fixing groove; 93. Positioning groove; 94. Explosion-proof film. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] As shown in Figures 1 to 9, a first aspect of the present invention provides an integrated battery pack 90 safety detection device, comprising: a plurality of PCB control boards 10 for communication connection with a BMS system, the PCB control boards 10 having a plurality of detection slots 11 corresponding to the safety valves of each battery cell, and the PCB control boards 10 being fixed to the top of the battery pack 90 and forming a predetermined distance between them and the safety valves; detection blocks 20 housed in each detection slot 11; a busbar 70, the busbar 70 including a plurality of aluminum bars 71 respectively corresponding to the positive / negative poles of each battery cell to realize the series connection of each individual battery cell; and a plurality of conductive connectors 80 respectively connected between each aluminum bar 71 and the PCB control board 10.

[0047] Specifically, the BMS system refers to the battery management system, which is used to centrally control the battery pack 90. ​​In this embodiment, the PCB control board 10 is used as the main control board to significantly reduce costs. A BMS acquisition chip is usually set on the PCB control board 10. The BMS chip realizes centralized data acquisition or processing and communicates with the BMS system to upload data.

[0048] The battery pack 90 has a base plate 91 fixed on top. The base plate 91 is made of insulating material. The base plate 91 has several fixing grooves 92 that are adapted to the PCB control board 10 and several positioning grooves 93 that are adapted to the aluminum bar sheet 71. The PCB control board 10 is embedded in the fixing groove 92 to form a predetermined distance with the safety valve. The fixing groove 92 has a through-hole corresponding to each safety valve. An explosion-proof film 94 can also be set above the base plate 91. The explosion-proof film 94 covers the PCB control and busbar 70. The explosion-proof film 94 also has a through-hole corresponding to the detection groove 11 for the detection block 20 to be bent.

[0049] The substrate 91 facilitates the installation and fixing of the PCB control board 10 and the aluminum bar 71, and enables the positioning of the PCB control board 10 and the aluminum bar 71 for conductive connection via the conductive connector 80. The substrate 91 also restricts the PCB control board 10 to form a predetermined distance from the safety valve. The opening is designed to allow the safety valve to pass through the impact detection block 20 when it is opened, and to restrict the electrolyte from being sprayed directionally onto the detection block 20.

[0050] A rigid first micro-connection structure 21 is connected between the first side of the detection block 20 and the PCB control board 10 to suspend the detection block 20 in the detection slot 11. Detection feet 22 are arranged on the first micro-connection structure 21. The detection block 20 can withstand the impact force of the safety valve opening to break the first micro-connection structure 21 and the detection feet 22 to form a first detection signal. The second side of the detection block 20, opposite to the first side, is connected to the PCB control board 10 with a second micro-connection structure 30. The second micro-connection structure 30 is flexible and deformable and can maintain the connection state when subjected to impact force. The back of the detection block 20 is densely covered with detection lines 40 connected to the second detection circuit 60 to change the parallel detection resistance value of the second detection circuit 60 when in contact with electrolyte to form a second detection signal.

[0051] Specifically, the detection block 20 is elliptical, oval, square, hexagonal, or similar in shape, and the detection slot 11 is also elliptical, oval, square, hexagonal, or similar in shape corresponding to the detection block 20. Preferably, both the detection block 20 and the detection slot 11 are elliptical, with the outer edge of the detection block 20 1-3 mm away from the edge of the detection slot 11. The area of ​​the detection block 20 is 1.1-1.3 times the area of ​​the safety valve switch, and under normal conditions, the distance between the detection block 20 and the safety valve is 1-3 mm. Preferably, the outer edge of the detection block 20 is 2 mm away from the edge of the detection slot 11, the area of ​​the detection block 20 is 1.2 times the area of ​​the safety valve switch, and under normal conditions, the distance between the detection block 20 and the safety valve is 2 mm.

[0052] The first micro-connection structure 21 includes two separately arranged connecting pins 211, the width of which is 1-2 mm, preferably 1.6 mm. The detection pin 22 includes a first pin 221 and a second pin 222 respectively arranged on the two connecting pins 211. The first pin 221 and the second pin 222 are connected to the first detection circuit 50. When the first pin 221 and / or the second pin 222 breaks, the resistance value of the first detection circuit 50 is changed to form a first detection signal.

[0053] It is understood that the first detection circuit 50 is printed on the PCB control board 10 and the detection block 20. The first detection circuit 50 includes a first detection resistor 51, a first pin 221 and a second pin 222 connected in parallel with the first detection resistor 51. When the first pin 221 and / or the second pin 222 is broken, the first detection resistor 51 can be disconnected, thereby causing the resistance value of the entire first detection circuit 50 to change, thereby forming a first detection signal to complete the valve opening detection.

[0054] The thickness of the PCB control board 10 is 1.4-1.8mm, preferably 1.6mm. Since the connecting leg 211 is directly formed inside the PCB control board 10, the thickness of the PCB control board 10 is the same as the thickness of the connecting leg 211. By setting an appropriate board thickness, the connecting leg 211 has appropriate load-bearing capacity, so that the detection block 20 can break after being subjected to appropriate impact force to realize valve opening detection.

[0055] The second micro-connection structure 30 uses a lamination process to achieve a soft connection between the detection block 20 and the PCB control board 10. The thickness of the second micro-connection structure 30 is 0.2-0.5mm. Preferably, the thickness of the second micro-connection structure 30 is set to 0.3mm, which can ensure that the second micro-connection structure 30 can be freely bent within a range of at least 90° without breaking. This allows for leakage detection even after the first micro-connection structure 21 breaks, achieving a dual-mode detection effect.

[0056] The detection line 40 includes a first line 41 and a second line 42. The first line 41 and the second line 42 are close to each other but do not touch each other. The first line 41 includes a first main line 411 and multiple first branch lines 412 connected to the first main line 411. The second line 42 includes a second main line 421 and multiple second branch lines 422 connected to the second main line 421. The first main line 411 basically surrounds the second line 42 and forms a detection area. The first branch lines 412 are located inside the first main line 411, and each first branch line 412 and each second branch line 422 are arranged alternately and sequentially. The first branch lines 412 and the second branch lines 422 are densely distributed in the detection area. The second main line 421 is located in the middle of the detection area, and the second branch lines 422 are located on both sides of the second main line 421.

[0057] In this circuit, a first terminal 413 is formed at one end of the first main line 411, and a second terminal 423 is formed by extending the first main line 411. The first terminal 413 and the second terminal 423 are connected to the second detection circuit 60. When the detection area comes into contact with electrolyte, the resistance between the first line 41 and the second line 42 changes to change the parallel detection resistance value of the second detection circuit 60 to form a second detection signal.

[0058] When the battery pack 90 malfunctions and causes the safety valve to open, electrolyte will splash outwards onto the detection area. The electrolyte will change the resistance between the first line 41 and the second line 42, thereby changing the parallel detection resistance value of the second detection circuit 60, which in turn causes a voltage change and generates a second detection signal. This second detection signal can be used as an alarm trigger signal and can realize leakage detection and valve opening detection. Since the first main line 411 surrounds the second line 42 to form the detection area, and the first branch line 412 and the second branch line 422 are densely distributed in the detection area, when the electrolyte comes into contact with any position in the detection area, the impedance change between the first line 41 and the second line 42 can be realized, which improves the detection efficiency and detection effect. The arrangement of the first branch line 412 and the second branch line 422 allows the circuit to be arranged more tightly, so that leakage detection can be achieved when only a small amount of electrolyte comes into contact with the detection area, thereby improving the detection accuracy.

[0059] The second main line 421 is linear and located at the central axis of the first main line 411. Specifically, the second main line 421 can be straight or wavy. In this embodiment, the second main line 421 is set to be straight. Multiple second branch lines 422 are symmetrically arranged on both sides of the second main line 421. One end of the second branch line 422 is connected to the second main line 421, and the other end extends close to the first main line 411.

[0060] In other embodiments, the second main line 421 may also be configured as an elongated oval shape, with the central axis of the second main line 421 aligned with the central axis of the first main line 411. Multiple second branch lines 422 are symmetrically arranged on both sides of the second main line 421, with one end of the second branch line 422 connected to the second main line 421 and the other end extending close to the first main line 411. When the second main line 421 is configured as an elongated oval shape, it is easier to etch and form.

[0061] The second detection circuit 60 includes a second detection resistor 61, which is connected in parallel with the second detection resistor 61 through the second micro-connection structure 30. When the detection area comes into contact with the electrolyte, the resistance value of the second detection circuit 60 is changed to form a second detection signal. When the detection area comes into contact with the electrolyte, the impedance between the first line 41 and the second line 42 can be changed. At the same time, the parallel second detection resistor 61 makes the change in resistance value more obvious, realizing leakage detection and improving detection accuracy.

[0062] Meanwhile, in some embodiments, the first detection resistor 51 and the second detection resistor 61 can both be connected to several precision adjustment resistors to further adjust the detection accuracy. It is understood that the first detection circuit 50 and the second detection circuit 60 are connected to the BMS acquisition chip to upload to the BMS system when a detection signal is generated.

[0063] The conductive connector 80 includes: an FPC connector body 81 electrically connected to the PCB control board 10, and a conductive sheet 82 for realizing the conductive connection between the FPC connector body 81 and the corresponding aluminum bar sheet 71. The conductive sheet 82 is provided with a temperature sensor 821 to directly collect the temperature information of the corresponding aluminum bar sheet 71.

[0064] Specifically, the first side of the FPC connection body 81 is provided with a connection pad 811 for electrical connection with the PCB control board 10, and the second side is formed with a connection ear 812 for electrical connection with the conductive sheet 82. The first end of the conductive sheet 82 is electrically connected to the connection ear 812, and the second end is electrically connected to the aluminum strip 71. In use, the FPC connection body 81 is soldered to the PCB control board 10 through the connection pad 811, and the conductive sheet 82 is soldered to the busbar 70, thereby forming a conductive connection between the PCB control board 10 and the busbar 70 by using the FPC connection body 81 and the conductive sheet 82 as conductors.

[0065] The FPC connector body 81 is pre-cut from the FPC substrate, which is usually polyimide. The connector pad 811 is a fixed soldering area on the FPC connector body 81, which can be soldered to the conductive solder points on the PCB control board 10 by means of soldering or other methods. The connector ear 812 is also provided with a soldering area for soldering to the conductive sheet 82. The size of the connector ear 812 needs to be sufficient to form a solder joint with the conductive sheet 82.

[0066] Meanwhile, a deformation groove 813 is formed in the FPC connector body 81 between the connector pad 811 and the connector lug 812, and a micro-connecting piece 814 is formed on one side of the deformation groove 813. The deformation groove 813 is elongated and located near the middle of the FPC connector body 81, so that the FPC connector body 81 can disperse the vibration force when subjected to mechanical vibration. The micro-connecting piece 814 is formed naturally after the deformation groove 813 is opened. The deformation groove 813 can further improve the mechanical buffering performance of the FPC connector body 81, while the micro-connecting piece 814 can maintain the structural stability of the FPC connector body 81 and reduce the deformation of the FPC connector body 81.

[0067] The aluminum strip 71 is used to connect adjacent individual cells in series. It can usually be connected to the cell by welding aluminum wire. The conductive sheet 82 is made of hard nickel to have better conductivity. The conductive sheet 82 can be welded to the busbar 70 by laser welding.

[0068] In this embodiment, the connecting ear 812 extends outward from the second side of the FPC connecting body 81, and the conductive sheet 82 is arranged along the extension direction parallel to the PCB control board 10. It can be understood that in this embodiment, the connecting ear 812 needs to extend above the aluminum bar sheet 71 so that when the conductive sheet 82 and the connecting ear 812 are soldered together, they are also located above the aluminum bar sheet 71 so that the two can be soldered together.

[0069] In another embodiment, as shown in Figures 8 and 9, the conductive sheet 82 is arranged along the extension direction perpendicular to the PCB control board 10. In this embodiment, the connecting ear 812 does not need to extend outward, but extends outward from the second end of the conductive sheet 82 to the top of the aluminum bar sheet 71 to facilitate the soldering connection between the two. The advantage of this method is that since there are conductive lines arranged on the FPC connecting body 81, when the connecting ear 812 extends outward to the aluminum bar sheet 71, it will inevitably overlap with the aluminum bar sheet 71, which poses a certain risk of leakage. However, in this embodiment, the FPC connecting body 81 will not overlap with the aluminum bar sheet 71, thereby eliminating the risk of leakage.

[0070] Temperature sensor 821 is disposed on conductive sheet 82 to collect temperature information transmitted by corresponding aluminum bar sheet 71. Conductive sheet 82 also has good thermal conductivity. Therefore, when temperature sensor 821 is in contact with conductive sheet 82, it can basically obtain the temperature of busbar 70. By placing temperature sensor 821 on conductive sheet 82, the collected temperature signal can be more accurate, so as to realize thermal runaway monitoring of battery pack 90.

[0071] Furthermore, the conductive sheet 82 is provided with a receiving groove 822 for receiving the temperature sensor 821. The receiving groove 822 is provided with symmetrical snap-fit ​​springs 823 on both sides. The snap-fit ​​springs 823 are used to snap and fix the temperature sensor 821. The snap-fit ​​springs 823 can be formed by bending the part of the conductive sheet 82 inside the receiving groove 822 upward to facilitate the connection and fixation of the temperature sensor 821. In addition, a welding groove 824 is provided on one side of the conductive sheet 82 located in the receiving groove 822 to facilitate the welding and fixation of the conductive sheet 82 and the connecting lug 812.

[0072] When the PCB control board 10 is assembled onto the battery pack 90, each detection block 20 corresponds to the safety valve. That is, the detection block 20 is located directly above the safety valve and forms a predetermined spacing. It is electrically connected to the busbar 70 through the conductive connector 80. Since the busbar 70 realizes the series connection of each cell, when the conductive connector 80 forms the busbar 70 and the PCB control board 10, the monitoring of the cell can be realized.

[0073] During testing, when a malfunction occurs in the battery pack 90 and causes the safety valve to open, an upward impact force is generated and acts on the detection block 20. The detection block 20 deforms upward under the impact force, which causes the first micro-connection structure 21 and the detection support 22 to break and generate the first detection signal. This first detection signal is the safety valve opening signal of the battery pack 90, thus realizing the safety valve opening detection.

[0074] Simultaneously, when the safety valve opens, electrolyte will be sprayed out. When the electrolyte splashes onto the back of the detection block 20, the detection line 40 will come into contact with the electrolyte. Since the electrolyte has good conductivity, the detection line 40 will conduct, changing the resistance value of the second detection circuit 60, which in turn causes a voltage change and generates a second detection signal. This second detection signal is the battery pack 90 leakage detection signal. Through this second detection signal, leakage detection and valve opening detection can be further realized.

[0075] The temperature sensor 821 can directly collect the temperature information of the aluminum foil 71, which can reflect the real-time temperature of the battery pack 90. ​​When the temperature value exceeds the predetermined temperature threshold, it can be determined that the battery pack 90 has thermal runaway and an abnormal signal indicating thermal runaway of the battery pack 90 can be generated.

[0076] Because the first micro-connection structure 21 is broken and valve opening is detected by directly bearing the impact force through the detection block 20, the detection is faster and the timeliness of detection is significantly improved. This provides a faster response for subsequent signal processing and improves the detection effect. At the same time, through the second micro-connection structure 30 and the detection line 40, leakage detection can also be performed simultaneously after the first micro-connection structure 21 breaks. Combined with the temperature detection of the temperature sensor 821, the thermal runaway situation can be further judged. The combination of multiple detection methods can effectively detect the state of the battery pack 90 in the early stage of thermal runaway, improving the accuracy and reference of the detection.

[0077] Furthermore, by setting the conductive connector 80 as a combination of the FPC connector body 81 and the conductive sheet 82, since the FPC connector body 81 has good tensile strength, it can buffer mechanical vibrations during transportation, reduce deformation of the conductive connection structure, effectively improve the overall tensile strength, increase flexibility and extensibility, and have better vibration resistance. This ensures a stable connection between the aluminum bar sheet 71 and the PCB control board 10, maintaining the effectiveness of the detection device.

[0078] A second aspect of the present invention provides a method for processing an integrated battery pack 90 safety detection device as described in the first aspect, comprising:

[0079] S100. Take a PCB substrate of suitable size and perform groove processing on the PCB substrate according to the predetermined process dimensions to form a number of detection slots 11. For each detection slot 11, form a detection block 20 and a first micro-connection structure 21. The first micro-connection structure 21 includes two spaced connecting legs 211. The connecting legs 211 are located on one side of the detection block 20 so that the detection block 20 is suspended in the detection slot 11. The outer edge of the detection block 20 is 1-3mm away from the edge of the detection slot 11. The area of ​​the detection block 20 is 1.1-1.3 times the area of ​​the safety valve switch. The width of the connecting legs 211 is 1-2mm.

[0080] S200. A second micro-connection structure 30 is formed between the detection block 20 and the PCB substrate using a lamination process. The lamination process can be used to add a soft connection structure between the PCB substrate and the detection block 20 by lamination. The soft connection structure is conductive. Preferably, the thickness of the second micro-connection structure 30 is 0.2-0.5mm to form a soft connection with the PCB substrate, and the upper surface of the second micro-connection structure 30 is basically flush with the surface of the PCB substrate.

[0081] S300, a first detection circuit 50 and a second detection circuit 60 are printed on a PCB substrate, and detection lines 40 are printed on each detection block 20 to form a PCB control board 10. The first micro-connection structure 21 has detection pins 22 connected to the first detection circuit 50, and the second detection circuit 60 is connected to the detection lines 40 through the second micro-connection structure 30.

[0082] The detection line 40 includes a first line 41 and a second line 42, which are close to each other but do not touch. The first line 41 includes a first main line 411 and multiple first branch lines 412 connected to the first main line 411. The second line 42 includes a second main line 421 and multiple second branch lines 422 connected to the second main line 421. The first main line 411 basically surrounds the second line 42 and forms a detection area. The first branch lines 412 are located inside the first main line 411, and each first branch line 412 and each second branch line 422 are arranged alternately and sequentially. The first branch lines 412 and the second branch lines 422 are densely distributed in the detection area. The second main line 421 is located in the middle of the detection area, and the second branch lines 422 are located on both sides of the second main line 421. The distance between the first branch lines 412 and the second branch lines 422 is 0.2-0.6 mm, preferably 0.5 mm.

[0083] S400, a pre-formed substrate 91 is fixed on the top of the battery pack 90, and aluminum strips 71 are sequentially inserted into the positioning grooves 93 on the substrate 91 to form a busbar 70 to connect each individual battery cell in series. The substrate 91 can be integrally formed from insulating material by vacuum forming, injection molding or other methods. After the forming is completed, a fixing groove 92 adapted to the PCB control board 10 and a positioning groove 93 adapted to the aluminum strips 71 are formed on the substrate 91. Positioning pins are also provided on the substrate 91. Several positioning holes adapted to the positioning pins are provided on the PCB control board 10 and the aluminum strips 71. During installation, the positioning pins are inserted into the positioning holes to realize the positioning and fixing of the aluminum strips 71 and the PCB control board 10. After the aluminum strips 71 are positioned and installed, they can be connected to the battery cells by aluminum wire welding.

[0084] S500: After the prepared PCB control board 10 is embedded into the fixing groove 92 on the substrate 91, the first side of the multiple pre-made conductive connectors 80 is electrically connected to each preset welding point on the PCB control board 10, and the second side is electrically connected to each aluminum bar sheet 71 to form a detection device for communication connection with the BMS system. The conductive connectors 80 can be pre-soldered on the PCB control board 10, or they can be soldered to the PCB control board 10 after the PCB control board 10 is installed on the substrate 91.

[0085] The method for preparing the conductive connector 80 includes:

[0086] S501. Conductive lines are formed on the FPC substrate according to the predetermined process flow. The specific process flow can adopt the existing FPC circuit board processing flow. At least one area with a corresponding conductive connection structure is formed on the FPC substrate, and the conductive lines are arranged in this area.

[0087] S502, The FPC substrate is punched to form an FPC connection body 81, wherein the first side of the FPC connection body 81 is provided with a connection pad 811 for electrical connection with the PCB control board 10, and the second side extends outward to form a connection ear 812.

[0088] It is understood that the conductive lines are located on the FPC connector body 81, thereby enabling the FPC connector body 81 to make conductive connections. The connecting pad 811 is a reserved welding area on the FPC connector body 81, which can be reserved and formed when forming the conductive lines. The connecting lug 812 is an outward protruding part on the FPC connector body 81. The connecting lug 812 is also provided with a welding area for welding and fixing with the conductive connecting piece. The size of the connecting lug 812 needs to be sufficient to form a weld with the conductive connecting piece.

[0089] Simultaneously, during the punching process to form the FPC connector body 81, a deformation groove 813 is formed between the connector pad 811 and the connector lug 812, and a micro-connecting piece 814 is formed on one side of the deformation groove 813. The deformation groove 813 is elongated and located near the middle of the FPC connector body 81, so that the FPC connector body 81 can disperse the vibration force when subjected to mechanical vibration. The micro-connecting piece 814 is formed naturally after the deformation groove 813 is opened. The deformation groove 813 can perform small deformations when the FPC connector body 81 is subjected to vibration to buffer the vibration force, thereby improving the mechanical buffering performance of the FPC connector body 81. The micro-connecting piece 814 can maintain the stability of the FPC connector body 81 structure and reduce the deformation of the FPC body.

[0090] S503. The pre-processed conductive sheet 82 and connecting ear piece 812 are welded and fixed to form a conductive connection structure. The conductive sheet 82 is strip-shaped and can be pre-stamped according to the design dimensions. The conductive sheet 82 and connecting ear piece 812 can be welded together by soldering, laser welding, or other methods. The conductive sheet 82 is preferably made of hard nickel sheet to have better conductivity. At the same time, a welding groove 824 is also stamped on one side of the conductive sheet 82 located in the receiving groove 822 to facilitate the welding connection between the conductive sheet 82 and the FPC connecting body 81.

[0091] S504. A temperature sensor 821 is provided in the conductive sheet 82 to directly collect the temperature information of the aluminum foil 71. A receiving groove 822 is also stamped on the conductive sheet 82. The temperature sensor 821 is placed in the receiving groove 822 and welded to the FPC connection body 81 to directly collect the temperature information transmitted by the corresponding busbar 70. It can be understood that the detection end of the temperature sensor 821 can contact the busbar 70 or the conductive sheet 82 to collect the corresponding temperature information. The conductive end of the temperature sensor 821 is welded to the FPC connection body 81 for conductive connection to transmit the collected temperature information to the PCB control board 10 to realize the temperature monitoring of the battery pack 90.

[0092] S505, the conductive connection structure is soldered to the preset connection point of the PCB control board 10 through the connection pad 811 so that the conductive piece 82 is located on the outside of the PCB control board 10 for electrical connection with the busbar 70. Specifically, the connection pad 811 can be soldered to the conductive solder point on the PCB control board 10 by means of soldering or other methods, and the conductive piece 82 can be soldered to the busbar 70 by laser welding.

[0093] In one embodiment, the connecting ear 812 extends outward from the second side of the FPC connecting body 81, and the conductive sheet 82 is arranged along the extension direction parallel to the PCB control board 10. It can be understood that the state after soldering is as shown in Figure 3. In this embodiment, the connecting ear 812 needs to extend above the aluminum bar sheet 71 so that when the conductive sheet 82 and the connecting ear 812 are soldered together, they are also located above the aluminum bar sheet 71 so that the two can be soldered together.

[0094] In another embodiment, the conductive sheet 82 is arranged along the extension direction perpendicular to the PCB control board 10. In this embodiment, the connecting ear 812 does not need to extend outward, but extends outward from the second end of the conductive sheet 82 to the top of the aluminum bar sheet 71 to facilitate the soldering connection between the two. In this embodiment, the part of the PCB control board 10 corresponding to the conductive connection structure is also provided with a relief groove. The relief groove can accommodate part of the structure of the FPC connection body 81, so that the FPC connection body 81 will not extend to the top of the aluminum bar sheet 71. The state after soldering is shown in Figure 9. The advantage of this method is that since there are conductive lines arranged on the FPC connection body 81, when the connecting ear 812 extends outward to the aluminum bar sheet 71, it will inevitably overlap with the aluminum bar sheet 71, which poses a certain risk of leakage. However, in this embodiment, the FPC connection body 81 will not overlap with the aluminum bar sheet 71, thereby eliminating the risk of leakage.

[0095] The FPC connector body 81 is used to realize the conductive connection between the PCB control board 10 and the conductive sheet 82. In order to facilitate processing, several conductive lines corresponding to the FPC connector body 81 are usually formed on the FPC substrate according to the FPC circuit board process flow. Then, the FPC connector body 81 is formed by punching to improve processing efficiency. The conductive sheet 82 can also be pre-stamped and formed. It serves as an intermediate conductive component to realize the conductive connection between the FPC connector body 81 and the busbar 70. The setting of the connecting ear 812 can facilitate the welding connection with the conductive sheet 82 to form a conductive connection structure. The setting of the connecting pad 811 can facilitate the welding connection with the PCB control board 10. After the conductive connection structure is welded to the PCB control board 10 through the connecting pad 811, when assembling the battery pack 90, after the PCB control board 10 is assembled into the corresponding position on the battery pack 90, the conductive sheet 82 can be directly connected to the busbar 70 to realize the conductive connection between the PCB control board 10 and the busbar 70.

[0096] The above process enables the installation and electrical connection of the battery cell, busbar 70, PCB control board 10 and conductive connector 80, and achieves efficient processing and forming of PCB control board 10 and conductive connector. By configuring the first micro-connection structure 21 and the first detection circuit 50, the second micro-connection structure 30 and the second detection circuit 60, and the temperature sensor 821, multiple detection methods are combined to effectively detect the state of the battery pack 90 in the early stage of thermal runaway, improving the accuracy and reference value of the detection.

[0097] To facilitate verification of the specific detection functions of different detection block sizes and structures, the following comparative experiments are provided:

[0098] Comparative Experiment 1

[0099] The probability of breakage of the connecting leg was tested by setting different size ratios between the detection block and the safety valve. Specifically, the size ratios of the detection block and the safety valve were set to 0.8:1, 1:1, and 1.2:1, respectively. Then, the detection block and the safety valve were set accordingly, and valve opening tests were performed to determine the probability of opening for different detection blocks. The specific test results are as follows:

[0100] The test results show that when the size ratio of the detection block to the safety valve is greater than 1.2, the detection block can be guaranteed to open 100% of the time.

[0101] Comparative Experiment 2

[0102] The breaking force of the connecting pins was tested using PCB control board thicknesses of 0.8mm, 1.0mm, 1.5mm, and 2.0mm. The detection blocks were then matched with the safety valves, and valve opening tests were performed to determine the breaking force of different detection blocks. The specific test results are as follows:

[0103] The test results show that when the PCB control board is 1.6mm thick, the connecting pins can be effectively broken under a 20N breaking force, without causing the detection block to be too easy to trigger a short circuit. In practical applications, since the second micro-connection structure can also form a connecting force, a thinner PCB control board can be set so that the connecting pins will not easily break during transportation.

[0104] Comparative Experiment 3

[0105] The leakage detection accuracy was tested by setting different spacings between the first and second lines. Specifically, spacings of 1mm, 0.8mm, 0.5mm, and 0.2mm were set. The detection blocks were then matched with the safety valves, and valve opening tests were performed to determine the leakage detection accuracy of different detection blocks. The specific test results are as follows:

[0106] The test results show that when the distance between the first and second lines is within the range of 0.5mm ± 0.1mm, high-precision leakage detection can be guaranteed, and the false alarm rate under high humidity is also within a reasonable range.

[0107] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These are all equivalent modifications and improvements made to the above embodiments based on the essential technology of the present invention, and all of these fall within the protection scope of the present invention.

Claims

1. An integrated battery pack safety detection device, characterized in that, include: Several PCB control boards are used for communication connection with the BMS system. The PCB control boards are provided with several detection slots corresponding to the safety valves of each battery cell. The PCB control boards are fixed to the top of the battery pack and form a predetermined distance between them and the safety valves. A detection block is housed within each of the aforementioned detection slots. A rigid first micro-connection structure connects the first side of the detection block to the PCB control board, allowing the detection block to be suspended within the detection slot. Detection feet are arranged on the first micro-connection structure. The detection block can withstand the impact force of the safety valve opening, causing the first micro-connection structure and detection feet to break and form a first detection signal. A second micro-connection structure is connected to the PCB control board on the second side of the detection block, opposite to the first side. The second micro-connection structure is flexible and deformable, and can maintain its connection state when subjected to impact force. The back of the detection block is densely covered with detection lines connected to a second detection circuit, used to change the parallel detection resistance value of the second detection circuit to form a second detection signal when in contact with electrolyte. The busbar includes several aluminum plates that are respectively configured to correspond to the positive / negative poles of each battery cell to realize the series connection of each individual battery cell; as well as, Several conductive connectors are respectively connected between each aluminum bar and the PCB control board. The conductive connectors include: an FPC connection body electrically connected to the PCB control board, and a conductive sheet for realizing the conductive connection between the FPC connection body and the corresponding aluminum bar. The conductive sheet is provided with a temperature sensor to directly collect the temperature information of the corresponding aluminum bar.

2. The integrated battery pack safety detection device according to claim 1, characterized in that, A base plate is fixed on the top of the battery pack. The base plate is provided with several fixing slots adapted to the PCB control board and multiple positioning slots adapted to the aluminum foil. The PCB control board is embedded in the fixing slots to form a predetermined distance with the safety valves, and the fixing slots are provided with openings corresponding to each safety valve.

3. The integrated battery pack safety detection device according to claim 1 or 2, characterized in that, The first micro-connection structure includes two separately arranged connection pins. The detection circuit includes a first pin and a second pin respectively arranged on the two connection pins. The first pin and the second pin are connected to a first detection circuit. When the first pin and / or the second circuit is broken, the resistance value of the first detection circuit is changed to form a first detection signal.

4. The integrated battery pack safety detection device according to claim 1 or 2, characterized in that, The detection circuit includes a first circuit and a second circuit, wherein the first circuit and the second circuit are close to each other but do not touch each other; The first line includes a first main line and multiple first branch lines connected to the first main line. The second line includes a second main line and multiple second branch lines connected to the second main line. The first main line basically surrounds the second line and forms a detection area. The first branch lines are located inside the first main line, and each first branch line and each second branch line are arranged alternately and sequentially. The first branch lines and second branch lines are densely distributed in the detection area. The second main line is located in the middle of the detection area, and the second branch lines are located on both sides of the second main line.

5. The integrated battery pack safety detection device according to claim 4, characterized in that, One end of the first main line has a first terminal, and the second main line extends out of the first main line and has a second terminal. The first terminal and the second terminal are connected to the second detection circuit. When the detection area comes into contact with electrolyte, the resistance between the first line and the second line changes to change the parallel detection resistance value of the second detection circuit to form a second detection signal.

6. The integrated battery pack safety detection device according to claim 1, characterized in that, The first side of the FPC connector body is provided with a connector pad for electrical connection with the PCB control board, and the second side is formed with a connector ear for electrical connection with the conductive sheet. The first end of the conductive sheet is electrically connected to the connector ear, and the second end is electrically connected to the aluminum foil.

7. The integrated battery pack safety detection device according to claim 6, characterized in that, The conductive sheet is arranged along an extension direction perpendicular to the PCB control board; Alternatively, the connecting tabs extend outward from the second side of the FPC connecting body, and the conductive sheets are arranged along an extension direction parallel to the PCB control board.

8. A method for manufacturing an integrated battery pack safety detection device as described in any one of claims 1-7, characterized in that, include: Take a PCB substrate of appropriate size, and perform groove processing on the PCB substrate according to the predetermined process dimensions to form a number of detection slots, and form a detection block and a first micro-connection structure corresponding to each detection slot; A second micro-connection structure is formed between the detection block and the PCB substrate using a lamination process; A PCB control board is formed by printing a first detection circuit and a second detection circuit on the PCB substrate and printing detection lines on each detection block. The first micro-connection structure has detection pins connected to the first detection circuit, and the second detection circuit is connected to the detection lines through the second micro-connection structure. A pre-formed substrate is fixed on the top of the battery pack, and aluminum foil is sequentially inserted into the positioning groove on the substrate to form a busbar to connect each individual cell in series. After the prepared PCB control board is embedded into the fixing groove on the substrate, the first side of multiple pre-made conductive connectors is electrically connected to each preset soldering point on the PCB control board, and the second side is electrically connected to each aluminum bar sheet to form a detection device for communication connection with the BMS system.

9. The method according to claim 8, characterized in that, The method for preparing the conductive connector includes: Conductive circuits are formed on the FPC substrate according to the predetermined process flow. The FPC substrate is punched to form an FPC connector body, wherein the first side of the FPC connector body is provided with a connector pad for electrical connection with the PCB control board, and the second side is formed with a connector ear. The pre-processed conductive sheet is welded and fixed to the connecting lug to form a conductive connection structure; A temperature sensor is installed inside the conductive sheet to directly collect temperature information of the aluminum foil. The conductive connection structure is soldered to a preset soldering point on the PCB control board via a connecting pad so that the conductive sheet is located on the outside of the PCB control board for electrical connection with the aluminum foil.

10. The method according to claim 9, characterized in that, When the FPC connection body is formed by punching, a deformation groove is formed between the connection pad and the connection lug, and a micro-connection piece is formed on one side of the deformation groove.

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