Safety detection device for thermal runaway of battery pack in extremely early stage and processing technology of safety detection device

Abstract

The invention discloses an extremely early battery pack thermal runaway safety detection device and a processing technology thereof, and the safety detection device comprises a plurality of control panels which are used for being in communication connection with a BMS system, and each control panel is provided with a connection plug-in; the plurality of detection sensors are arranged between two adjacent battery cells and are used for detecting expansion pressure generated by the battery cells so as to feed back a pressure detection value to the BMS system; and a conductive connector, the detection sensor comprises a plurality of flexible pressure sensors and pressure bearing sheets which are arranged on the two sides of the flexible pressure sensors in an attached mode. The flexible pressure sensor comprises a sensing part and a feedback part, the sensing part is used for receiving the pressure of the pressure bearing sheet to form a pressure detection value, and the feedback part is used for feeding back the pressure detection value; and the pressure bearing sheet is attached to the sensing part. According to the invention, early thermal runaway early warning can be realized by detecting the expansion pressure, so that the thermal runaway detection accuracy and safety of the battery cell are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery packs, and in particular, to an ultra-early battery pack thermal runaway safety detection device and its processing technology. Background Art

[0002] Currently, wind power generation and photovoltaic power generation usually use batteries for energy storage. In order to improve the reliability and safety of energy storage batteries, it is particularly important to perform safety detection on energy storage batteries. Currently, the more commonly used means for monitoring energy storage batteries mainly include lithium battery voltage monitoring and temperature monitoring. The voltage monitoring method collects the voltage of the battery module and judges whether there is a risk of thermal runaway according to the voltage change. The temperature detection method usually arranges single-point or multi-point temperature sensors on the aluminum busbar of the battery module to obtain the temperature information during the operation of the battery module, and judges whether there is a risk of thermal runaway according to the temperature information.

[0003] However, the battery usually has a multi-layer winding or stacking structure inside, and coupled with the external packaging, once internal failure warning signals such as lithium deposition occur, the temperature transmission to the external aluminum busbar has a certain degree of distortion and lag, resulting in the inability of the external temperature sensor to respond in a timely manner to the failure of the lithium battery, that is, there is a certain lag in thermal runaway. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide an ultra-early battery pack thermal runaway safety detection device and its processing technology, which have the advantages of being able to realize thermal runaway detection extremely early, improving the detection accuracy and safety.

[0005] The purpose of the present invention is achieved by the following technical solutions: According to the first aspect of the embodiments of the present disclosure, an ultra-early battery pack thermal runaway safety detection device is provided, including: A plurality of control boards for communication connection with the BMS system, and connection plugs are provided at positions corresponding to adjacent positions of each battery cell on the control board; A plurality of detection sensors disposed between adjacent two battery cells and electrically connected to the connection plugs, for detecting the expansion pressure generated by the battery cells to feedback a pressure detection value to the BMS system; and, A conductive connecting member for electrically connecting the control board and the battery cells; Wherein, the detection sensor includes: a plurality of flexible pressure sensors, and pressure-bearing pieces attached to both sides of the flexible pressure sensors; The flexible pressure sensor includes a sensing part and a feedback part. The sensing part is used to receive the pressure of the pressure-bearing piece to form a pressure detection value, and the feedback part is used to connect with the battery control system to feedback the pressure detection value; The pressure-bearing piece is attached to the sensing part.

[0006] To implement the above technical solution, the control board is electrically connected to the battery cell through a conductive connector, so that the battery cell can supply power to the conductive connector and collect the operating parameters of the battery cell. The detection sensor is electrically connected to the connection plug, and the collected data can be fed back to the control board for processing and finally fed back to the BMS system by the control board. When in use, the detection sensor is arranged between two adjacent battery cells in the battery pack, and both sides of the detection sensor are closely attached to the sides of the adjacent two battery cells. At this time, the pressure generated by the expansion caused by thermal runaway during the operation of the battery cell will act on the side of the detection sensor. Since the pressure-bearing piece is attached to the side of the battery cell, when abnormal thermal runaway expansion occurs at any position of the battery cell, it will act on the pressure-bearing piece, and then apply pressure to the flexible pressure sensor. The sensing part of the flexible pressure sensor continuously detects the pressure to obtain the pressure detection value and feeds it back to the BMS system through the feedback part. Once the pressure detection value exceeds the predetermined pressure threshold, it can be determined that the battery cell is about to have a thermal runaway or other situations, so as to give an alarm prompt in time. Since the abnormal expansion of the battery cell is a phenomenon in the initial stage of the thermal runaway situation, the early warning of thermal runaway can be realized by detecting the expansion pressure, and the flexible pressure sensor can accurately and effectively reflect the change of the expansion force of the battery cell, greatly improving the accuracy and safety of the thermal runaway detection of the battery cell.

[0007] In some exemplary embodiments, the sensing part extends close to the middle of the pressure-bearing piece and corresponds to the middle of the battery cell. A connection terminal is provided at the end of the feedback part, and the connection terminal is used for electrically connecting to the connection plug.

[0008] Implementing the above technical solution can more effectively and accurately detect the expansion force of the battery cell, and the connection terminal can facilitate the electrical connection with the battery control system.

[0009] In some exemplary embodiments, the pressure-bearing piece can cover the side of the battery cell, and the pressure-bearing piece is one of a ceramic piece, a glass piece, and a mica piece.

[0010] Implementing the above technical solution can collect the pressure when abnormal thermal runaway expansion occurs at any position of the battery cell.

[0011] In some exemplary embodiments, a packaging piece is further provided outside the pressure-bearing piece for integrally packaging the flexible pressure sensor and the pressure-bearing piece. The packaging piece is made of a flexible film material and is thermally pressed and packaged outside the pressure-bearing piece; An adhesive layer is provided on the outside of the packaging piece for adhesively fixing to the side of the battery cell.

[0012] Implementing the above technical solution, through the integral packaging with the packaging piece and configuring the adhesive layer, it is convenient to adhesively fix the detection sensor to the side of the battery cell and simplify the installation process.

[0013] In some exemplary embodiments, it further includes a busbar, and the busbar includes a plurality of aluminum tabs respectively arranged corresponding to the positive / negative electrodes of each battery cell to realize the series connection of each battery cell, and the conductive connection member is electrically connected to the aluminum tab.

[0014] To implement the above technical solution, the conductive connection member is electrically connected to the busbar. Since the busbar realizes the series connection of each battery cell, when the conductive connection member forms an electrical connection between the busbar and the control board, the monitoring of the battery cell can be realized.

[0015] In some exemplary embodiments, the control board is further provided with a plurality of detection slots corresponding to the safety valves of each battery cell. A detection block is arranged in each detection slot. A rigid micro-connection structure is connected between the detection block and the control board to suspend the detection block in the detection slot. Detection legs are arranged on the micro-connection structure. The detection block can receive the impact force when the safety valve is opened so that the micro-connection structure and the detection legs break to form a break detection signal.

[0016] To implement the above technical solution, when the control board is assembled to the battery pack, the detection block corresponds to the safety valve and is located directly above the safety valve. When the detection sensor fails, or after the detection sensor issues a thermal runaway alarm and the supervisor has not dealt with it until the thermal runaway limit is finally reached, at this time, the expansion of the battery cell will cause the safety valve to open. The action of the safety valve spool forms an upward impact force, which acts on the detection block. The detection block will deform upward under the action of the impact force, and then the micro-connection structure and the detection legs will break to generate a break detection signal. This detection signal is the safety valve opening signal of the battery pack, realizing the opening detection of the safety valve, further expanding the alarm method, and improving the safety of detection.

[0017] In some exemplary embodiments, a substrate is fixed on the top of the battery pack. The substrate is provided with a plurality of fixing slots adapted to the control board and a plurality of positioning slots adapted to the aluminum tabs. The control board is embedded in the fixing slots to form a predetermined distance from the safety valve, and through holes corresponding to each safety valve are provided in the fixing slots.

[0018] To implement the above technical solution, by providing the substrate, it is convenient to install and fix the control board and the aluminum tabs, and the control board and the aluminum tabs can be positioned, so as to conduct electrical connection through the conductive connection member, and the control board and the safety valve can form a predetermined distance through the limitation of the substrate. The through holes are provided for the safety valve to pass through when it is opened to impact the detection block.

[0019] According to the second aspect of the embodiments of the present disclosure, a process for manufacturing the early-stage battery pack thermal runaway safety detection device as described in the first aspect is provided, including: Take a circuit board substrate of appropriate size, and perform grooving processing on the circuit board substrate according to a predetermined process size to form a number of connection through-holes; Set connection plugs at positions corresponding to each connection through-hole on the circuit board substrate to form a control board; Attach the prefabricated pressure-bearing sheets on both sides of the flexible pressure sensor and encapsulate them into one body to form a standby detection sensor; After sequentially passing a number of detection sensors through the connection through-holes on the control board and electrically connecting them to the connection plugs, place the detection sensors in close contact between adjacent battery cells to form a detection device for communicating with the BMS system.

[0020] In summary, compared with the prior art, the present invention has the following beneficial effects: In the embodiment of the present invention, by providing an ultra-early battery pack thermal runaway safety detection device and its processing technology, the control board is electrically connected to the battery cell through a conductive connection member, so that the battery cell can supply power to the conductive connection member, and the working parameters of the battery cell can be collected. The detection sensor is electrically connected to the connection plug, and the collected data can be fed back to the control board for processing, and finally fed back to the BMS system by the control board. When in use, the detection sensor is arranged between two adjacent battery cells in the battery pack, and both sides of the detection sensor are closely attached to the sides of the adjacent two battery cells. At this time, the pressure generated by the expansion caused by thermal runaway during the operation of the battery cell will act on the side of the detection sensor. Since the pressure-bearing sheet is attached to the side of the battery cell, when abnormal thermal runaway expansion occurs at any position of the battery cell, it will act on the pressure-bearing sheet, and then apply pressure to the flexible pressure sensor. The sensing part of the flexible pressure sensor performs pressure detection in real time to obtain a pressure detection value, and feeds it back to the BMS system through the feedback part. Once the pressure detection value exceeds a predetermined pressure threshold, it can be determined that the battery cell is about to have a thermal runaway, etc., so as to give an alarm prompt in time. Since the abnormal expansion of the battery cell is a phenomenon in the initial stage of the thermal runaway situation, the thermal runaway early warning can be realized by detecting the expansion pressure, and the flexible pressure sensor can accurately and effectively reflect the change of the expansion force of the battery cell, greatly improving the accuracy and safety of the battery cell thermal runaway detection. Description of the Drawings

[0021] Figure 1 It is a schematic structural diagram of the ultra-early battery pack thermal runaway safety detection device in the embodiment of the present invention.

[0022] Figure 2 It is an exploded view of the ultra-early battery pack thermal runaway safety detection device in the embodiment of the present invention.

[0023] Figure 3 It is Figure 2 The enlarged view of part A in

[0024] Figure 4This is an explosion schematic diagram of the detection sensor in the embodiment of the present invention.

[0025] Figure 5 This is an arrangement schematic diagram of the detection feet in the embodiment of the present invention.

[0026] The corresponding component names represented by the numbers and letters in the figure: 10. Control board; 11. Connection plug; 12. Detection notch; 13. Detection block; 131. Micro-connection structure; 132. Detection foot; 20. Detection sensor; 21. Flexible pressure sensor; 211. Sensing part; 212. Feedback part; 213. Connection terminal; 22. Pressure-bearing piece; 23. Encapsulation piece; 231. Adhesive layer; 30. Conductive connection piece; 40. Busbar metal row; 41. Aluminum bar piece; 50. Substrate; 51. Fixed groove; 52. Positioning groove; 53. Through hole; 60. Electric core. Specific embodiments

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] As Figures 1 to 5 shown, in the first aspect of the embodiment of the present invention, an ultra-early battery pack thermal runaway safety detection device is provided, including: a plurality of control boards 10 for communication connection with the BMS system, and connection plugs 11 are arranged at positions adjacent to each electric core 60 on the control board 10; a plurality of detection sensors 20 arranged between two adjacent electric cores 60 and electrically connected to the connection plugs 11, for detecting the expansion pressure generated by the electric core 60 to feedback the pressure detection value to the BMS system; and a conductive connection piece 30 for electrically connecting the control board 10 and the electric core 60.

[0029] Specifically, the BMS system refers to the battery management system, which is used for centralized control of the battery pack. In this embodiment, the control board 10 can be selected from a flexible circuit board or a PCB circuit board. Preferably, a PCB circuit board is used to significantly reduce the cost. Usually, a BMS acquisition chip is arranged on the control board 10, and centralized acquisition or processing of data is realized through the BMS chip, and communication connection with the BMS system is carried out to realize data upload.

[0030] The detection sensor 20 includes: a plurality of flexible pressure sensors 21, and pressure-bearing sheets 22 attached to both sides of the flexible pressure sensors 21; the flexible pressure sensor 21 includes a sensing part 211 and a feedback part 212, the sensing part 211 is used to receive the pressure of the pressure-bearing sheet 22 to form a pressure detection value, and the feedback part 212 is used to be connected to the battery control system to feedback the pressure detection value; the pressure-bearing sheet 22 is attached to the sensing part 211.

[0031] The flexible pressure sensor 21 is an electrical device whose resistance value decreases as the pressure acting on the pressure-sensitive area increases. It senses the pressure change through the pressure-sensitive area to generate a resistance change, and then the pressure detection can be realized according to the generated electrical signal change. The flexible pressure sensor 21 is composed of a polymer pressure-sensitive material with excellent comprehensive mechanical properties and a high weather resistance thin film encapsulation material, and has excellent temperature resistance, sensitivity and anti-creep characteristics. Compared with other pressure sensors, the flexible pressure sensor 21 has obvious advantages in terms of linearity, hysteresis, drift and sensitivity.

[0032] The flexible pressure sensor 21 includes a sensing part 211 and a feedback part 212. The sensing part 211 is the above-mentioned pressure-sensitive area. The sensing part 211 is used to receive the pressure of the pressure-bearing sheet 22 to form a pressure detection value, and the feedback part 212 is used to be connected to the battery control system to feedback the pressure detection value. Among them, the sensing part 211 extends close to the middle of the pressure-bearing sheet 22 and corresponds to the middle of the battery cell 60. Since the battery cell 60 usually starts to expand and deform from the middle, setting the sensing part 211 in the middle position can detect the expansion force of the battery cell 60 more effectively and accurately. A connection terminal 213 is provided at the end of the feedback part 212. The connection terminal 213 can be structures such as a conductive connector or a conductive connection sheet. Correspondingly, the connection plug 11 is an interface part adapted to the connection terminal 213 to facilitate the electrical connection with the battery control system.

[0033] The pressure-bearing sheet 22 is attached to the sensing part 211, and the pressure-bearing sheet 22 can cover the side surface of the battery cell 60. Usually, the size and shape of the pressure-bearing sheet 22 are the same as the side surface of the battery cell 60. The pressure-bearing sheet 22 is one of a ceramic sheet, a glass sheet and a mica sheet. Preferably, the pressure-bearing sheet 22 is made of a mica sheet.

[0034] Outside the pressure-bearing sheet 22, there is also a packaging sheet 23 for integrally packaging the flexible pressure sensor 21 and the pressure-bearing sheet 22. The packaging sheet 23 is made of flexible film material and is hot-pressed and packaged outside the pressure-bearing sheet 22. During the hot-pressing process, the flexible film wraps the pressure-bearing sheet 22 and the flexible pressure sensor 21 for packaging. And on the outer side of the packaging sheet 23, there is an adhesive layer 231, and the adhesive layer 231 is used for bonding and fixing with the side surface of the battery cell 60, so as to bond and fix the detection sensor 20 to the side surface of the battery cell 60, simplifying the installation process; in some embodiments, a release layer can also be provided outside the adhesive layer 231 to prevent the detection sensor 20 from bonding with other objects when not installed, and the release layer can be removed during installation to bond and fix with the battery cell 60.

[0035] During use, both sides of the detection sensor 20 are bonded and fixed to the side surfaces of two adjacent battery cells 60 through the adhesive layer 231 at the same time, and the installation of the detection sensor 20 can be realized. Preferably, a sensor is provided between each adjacent pair of battery cells 60. In some embodiments, two battery cells 60 can also be taken as a group, and a detection sensor 20 is provided between the two battery cells 60 in each group, and no such detection sensor 20 is provided between adjacent groups. This setting method can reduce the usage of sensors, but the corresponding detection effect will also be weakened.

[0036] In actual application, two or more groups of detection sensors 20 can be provided between two adjacent battery cells 60, for example, 2-6 groups are provided. The sensing parts 211 of each group of detection sensors 20 are linearly or arrayedly distributed. Of course, in some embodiments, multiple sensing parts 211 can also be provided on the detection sensor 20, and the multiple sensing parts 211 can also be linearly or arrayedly distributed, so as to form a more accurate and effective pressure detection.

[0037] Furthermore, the device also includes a busbar metal row 40. The busbar metal row 40 includes a plurality of aluminum bar pieces 41 respectively corresponding to the positive / negative electrodes of each battery cell 60 to realize the series connection of each battery cell 60, and the conductive connecting piece 30 is electrically connected to the aluminum bar piece 41. The conductive connecting piece 30 can adopt the existing structure. Through the conductive connecting piece 30, it is electrically connected to the busbar metal row 40. Since the busbar metal row 40 realizes the series connection of each battery cell 60, when the conductive connecting piece 30 forms an electrical connection between the busbar metal row 40 and the control board 10, the monitoring of the battery cell 60 can be realized.

[0038] Further, a plurality of detection notches 12 corresponding to the safety valves of each battery cell 60 are provided on the control board 10. A detection block 13 is provided in each detection notch 12. A rigid micro-connection structure 131 is connected between the detection block 13 and the control board 10 to suspend the detection block 13 in the detection notch 12. Detection support feet 132 are arranged on the micro-connection structure 131. The detection block 13 can withstand the impact force when the safety valve is opened, causing the micro-connection structure 131 and the detection support feet 132 to break and form a break detection signal.

[0039] The detection block 13 can be set to a rectangular, oval, circular, polygonal or any combined shape. The micro-connection structure 131 is arranged on one side outside the detection. The detection support feet 132 can specifically include a first support foot and a second support foot. The first support foot and the second support foot are connected to the detection circuit. When the first support foot and / or the second circuit break, the resistance value of the detection circuit changes to form a detection signal. It can be understood that the detection circuit is printed on the control board 10 and the detection block 13. The first support foot and the second support foot are connected with a detection resistor. Under normal circumstances, the detection resistor is connected in parallel to the detection circuit through the first support foot and the second support foot. When the first support foot and / or the second support foot break, the detection resistor forms an open circuit, causing the resistance value of the entire detection circuit to change. The detection circuit detects the change in the electrical signal to form a detection signal, determines that the safety valve has opened, and completes the open valve detection.

[0040] When the control board 10 is assembled to the battery pack, the detection block 13 corresponds to the safety valve and is located directly above the safety valve. When the detection sensor 20 fails, or after the detection sensor 20 issues a thermal runaway alarm and the supervisor has not dealt with it until the thermal runaway limit is finally reached, at this time, the expansion of the battery cell 60 will cause the safety valve to open. The safety valve spool moves to form an upward impact force, which acts on the detection block 13. The detection block 13 deforms upward under the action of the impact force, causing the micro-connection structure 131 and the detection support feet 132 to break and generate a break detection signal. This detection signal is the open valve signal of the battery pack safety valve, realizing the open valve detection of the safety valve, further expanding the alarm method, and improving the safety of detection.

[0041] For the convenience of assembly, a substrate 50 is fixed to the top of the battery pack. The substrate 50 is made of an insulating material. The substrate 50 is provided with a plurality of fixing grooves 51 adapted to the control board 10 and a plurality of positioning grooves 52 adapted to the aluminum bar pieces 41. Of course, for the convenience of installing the detection sensor 20, holes for the detection sensor 20 to pass through also need to be provided on the control board 10. The control board 10 is embedded in the fixing groove 51 to form a predetermined distance from the safety valve, and a through port 53 corresponding to each safety valve is provided in the fixing groove 51; in some embodiments, an explosion-proof film can also be provided above the substrate 50. The explosion-proof film covers the control board 10 and the busbar 40, and a through port 53 corresponding to the detection slot 12 is also provided on the explosion-proof film for the detection block 13 to bend.

[0042] By providing the substrate 50, it is convenient to install and fix the control board 10 and the aluminum bar pieces 41, and the control board 10 and the aluminum bar pieces 41 can be positioned, so as to conduct electrical connection through the conductive connecting piece 30. And through the limitation of the substrate 50, a predetermined distance can be formed between the control board 10 and the safety valve. The through port 53 is provided for the safety valve to pass through and impact the detection block 13 when it is opened.

[0043] In the present invention, the control board 10 is electrically connected to the battery cell 60 through the conductive connecting piece 30, so that the battery cell 60 can supply power to the conductive connecting piece 30 and collect the working parameters of the battery cell 60. The detection sensor 20 is electrically connected to the connection plug 11, and the collected data can be fed back to the control board 10 for processing, and finally fed back to the BMS system by the control board 10; during use, the detection sensor 20 is arranged between two adjacent battery cells 60 in the battery pack, and both sides of the detection sensor 20 are closely attached to the sides of the adjacent two battery cells 60. At this time, the pressure generated by the expansion of the battery cell 60 due to thermal runaway during operation will act on the side of the detection sensor 20. Since the pressure-bearing piece 22 is attached to the side of the battery cell 60, when any position of the battery cell 60 has abnormal thermal runaway expansion, it will act on the pressure-bearing piece 22, and then apply pressure to the flexible pressure sensor 21. The sensing part 211 of the flexible pressure sensor 21 detects the pressure in real time to obtain the pressure detection value, and feeds it back to the BMS system through the feedback part 212. Once the pressure detection value exceeds a predetermined pressure threshold, it can be determined that the battery cell 60 is about to have a thermal runaway or other situations, so as to give an alarm prompt in time; since the abnormal expansion of the battery cell 60 is a phenomenon in the initial stage of the thermal runaway situation, the thermal runaway early warning in the very early stage can be realized by detecting the expansion pressure, and the flexible pressure sensor 21 can accurately and effectively reflect the change of the expansion force of the battery cell 60, greatly improving the accuracy and safety of the thermal runaway detection of the battery cell 60.

[0044] A second aspect of the embodiment of the present invention provides a process for manufacturing an extremely early battery pack thermal runaway safety detection device as in the first aspect, including: S11. Take a circuit board substrate of appropriate size, and perform grooving processing on the circuit board substrate according to a predetermined process size to form a number of connection through-holes. The connection through-holes can be rectangular or waist-shaped. Of course, when it is necessary to configure the detection block 13, a number of detection slots 12 are synchronously processed during the grooving processing, and a detection block 13 and a micro-connection structure 131 are formed corresponding to each detection slot 12. Among them, the micro-connection structure 131 is located on one side of the detection block 13 so that the detection block 13 is cantilevered in the detection slot 12. The outer edge of the detection block 13 without the micro-connection structure 131 is 1-3 mm away from the edge of the detection slot 12. The area of the detection block 13 is 1.1-1.3 times the area of the safety valve switch, and the width of the micro-connection structure 131 is 1-2 mm.

[0045] S12. Set connection plugs 11 at the positions corresponding to each connection through-hole on the circuit board substrate to form a control board 10. The connection plugs 11 can be electrically connected to the control board 10 by means of soldering, etc. Of course, if the detection block 13 is configured, a detection circuit, that is, detection pins 132, also needs to be printed on the circuit board substrate. The detection pins 132 are arranged on the micro-connection structure 131. The detection pins 132 specifically can include a first pin and a second pin. The first pin and the second pin are connected to the detection circuit. When the first pin and / or the second circuit is broken, the resistance value of the detection circuit changes to form a detection signal. It can be understood that the detection circuit is printed on the control board 10 and the detection block 13. The first pin and the second pin are connected with a detection resistor. Under normal circumstances, the detection resistor is connected in parallel to the detection circuit through the first pin and the second pin. When the first pin and / or the second pin is broken, the detection resistor forms an open circuit, so that the resistance value of the entire detection circuit changes. The detection circuit detects the change in the electrical signal to form a detection signal, and determines that the safety valve is opened, completing the opening detection.

[0046] S13. Fit and set the prefabricated pressure-bearing sheet 22 on both sides of the flexible pressure sensor 21 and encapsulate them into one body to form a detection sensor 20 for standby. The pressure-bearing sheet 22 is preferably made of mica sheet. The pressure-bearing sheet 22 and the flexible pressure sensor 21 can be thermally pressed and encapsulated by an encapsulation sheet 23 made of flexible film material. In some embodiments, the flexible pressure sensor 21 or a conventional pressure sensor can also be directly used as the detection sensor 20.

[0047] S14. After passing a number of detection sensors 20 through the connection through-holes on the control board 10 in sequence and electrically connecting them to the connection plugs 11, place the detection sensors 20 in a fitting manner between adjacent battery cells 60 to form a detection device for communicating with the BMS system.

[0048] Specifically, when assembling the battery pack, the preformed substrate 50 can be fixed to the top of the battery pack at the same time, and the aluminum bar pieces 41 are sequentially loaded into the positioning slots 52 on the substrate 50 to form a busbar metal row 40 for connecting each single cell 60 in series; among them, the substrate 50 can be integrally formed by insulating materials in ways such as thermoforming and injection molding. After the forming is completed, a fixing slot 51 adapted to the control board 10 and a positioning slot 52 adapted to the aluminum bar piece 41 are formed on the substrate 50, and positioning pins are also arranged on the substrate 50. A number of positioning holes adapted to the positioning pins are provided on both the control board 10 and the aluminum bar piece 41. During installation, the positioning pins are inserted into the positioning holes to achieve the positioning and fixing of the aluminum bar piece 41 and the control board 10. After the aluminum bar piece 41 is positioned and installed, it can be connected to the cell 60 by aluminum wire welding.

[0049] After the control board 10 is embedded in the fixing slot 51 on the substrate 50, the first sides of a plurality of prefabricated conductive connectors 30 are electrically connected to the respective welding sites preset on the control board 10, and the second sides are electrically connected to the respective aluminum bar pieces 41. The conductive connectors 30 can be pre-welded on the control board 10 first, or can be welded to the control board 10 after the control board 10 is installed on the substrate 50.

[0050] Through the above process, the installation and electrical connection of the cell 60, the busbar metal row 40, the control board 10, and the conductive connector 30 are realized. Through the configured micro-connection structure 131 and the detection circuit, multiple detection methods are combined with each other, which can effectively detect the state in the early stage of thermal runaway of the battery pack and improve the accuracy and safety of detection.

[0051] The above embodiments only represent several implementation manners of the present invention, and the description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can be made. These are all equivalent modifications and evolutions made to the above embodiments based on the essence of the present invention, and all of these belong to the protection scope of the present invention.

Claims

1. An extremely early-stage battery pack thermal runaway safety detection device, characterized in that, Including: A number of control boards for communication connection with the BMS system, and connection plugs are provided at positions corresponding to adjacent positions of each battery cell on the control board; A number of detection sensors arranged between adjacent two battery cells and electrically connected to the connection plugs, which are used to detect the expansion pressure generated by the battery cells to feedback the pressure detection value to the BMS system; And, A conductive connecting piece for electrically connecting the control board and the battery cells; Wherein, the detection sensor includes: a number of flexible pressure sensors, and pressure-bearing pieces attached to both sides of the flexible pressure sensors; The flexible pressure sensor includes a sensing part and a feedback part. The sensing part is used to receive the pressure of the pressure-bearing piece to form a pressure detection value, and the feedback part is used to be connected to the battery control system to feedback the pressure detection value; The pressure-bearing piece is attached to the sensing part.

2. The very-early-stage battery pack thermal runaway safety detection device according to claim 1, wherein The sensing part extends close to the middle of the pressure-bearing piece and corresponds to the middle of the battery cell. A connection terminal is provided at the end of the feedback part, and the connection terminal is used for electrical connection with the connection plug.

3. The very-early-stage battery pack thermal runaway safety detection device according to claim 1 or 2, characterized in that The pressure-bearing piece can cover the side of the battery cell, and the pressure-bearing piece is one of a ceramic piece, a glass piece and a mica piece.

4. The very-early-stage battery pack thermal runaway safety detection device according to claim 3, characterized in that, An encapsulation piece is further provided outside the pressure-bearing piece for integrally encapsulating the flexible pressure sensor and the pressure-bearing piece. The encapsulation piece is a flexible film material and is thermally pressed and encapsulated outside the pressure-bearing piece; An adhesive layer is provided on the outer side of the encapsulation piece for adhesively fixing to the side of the battery cell.

5. The early-stage battery pack thermal runaway safety detection device according to claim 1, characterized in that, It further includes a busbar metal row. The busbar metal row includes a number of aluminum bar pieces respectively corresponding to the positive / negative electrodes of each battery cell to realize the series connection of each battery cell, and the conductive connecting piece is electrically connected to the aluminum bar pieces.

6. The very-early-stage battery pack thermal runaway safety detection device according to claim 1, characterized in that, Detection notch openings corresponding to the safety valves of each battery cell are further provided on the control board. A detection block is provided in each detection notch opening. A rigid micro-connection structure is connected between the detection block and the control board so that the detection block is suspended in the detection notch opening. Detection support feet are arranged on the micro-connection structure. The detection block can receive the impact force when the safety valve is opened so that the micro-connection structure and the detection support feet are broken to form a break detection signal.

7. The very-early-stage battery pack thermal runaway safety detection device according to claim 1, characterized in that A substrate is fixed on the top of the battery pack. A number of fixing slots adapted to the control board and a plurality of positioning embedding slots adapted to the aluminum bar pieces are provided on the substrate. The control board is embedded in the fixing slots to form a predetermined distance from the safety valve, and through openings corresponding to each safety valve are provided in the fixing slots.

8. A process for manufacturing an extremely early-stage battery pack thermal runaway safety detection device as described in any one of claims 1-7, characterized in that, Including: Select a circuit board substrate with appropriate dimensions, and perform grooving processing on the circuit board substrate according to a predetermined process dimension to form a number of connection through-holes; Connection plugs are arranged at positions corresponding to each connection through-hole on the circuit board substrate to form a control board; The prefabricated pressure-bearing pieces are attached to both sides of the flexible pressure sensors and encapsulated into one body to form a standby detection sensor; After a number of detection sensors are sequentially passed through the connection through-holes on the control board and electrically connected to the connection plugs, the detection sensors are attached and placed between each adjacent battery cell to form a detection device for communication connection with the BMS system.

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