Early-stage battery pack thermal runaway safety detection device

Abstract

The utility model discloses an extremely early battery pack thermal runaway safety detection device, include: a plurality of control panel for with BMS system communication connection, be equipped with the connecting plug on the control panel, a plurality of detection sensor between the adjacent two electric core setting, be used for detecting the expansion pressure of electric core generation to the pressure detection value of feedback pressure to BMS system, and, conductive connecting piece, wherein, detection sensor includes: a plurality of flexible pressure sensor and the pressure -bearing piece of setting in the flexible pressure sensor both sides, and the flexible pressure sensor includes sensing part and feedback part, and sensing part is used to receive the pressure of pressure -bearing piece to form pressure detection value, and feedback part is used to feedback pressure detection value, pressure -bearing piece with sensing part is pasted. The utility model discloses through the mode of detecting expansion pressure can realize extremely early thermal runaway early warning, and the electric core thermal runaway detection accuracy and security are greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of battery pack technology, and in particular to a safety detection device for very early thermal runaway of battery packs. Background Technology

[0002] Currently, wind power and photovoltaic power generation typically use batteries for energy storage. To improve the reliability and safety of these batteries, safety testing is crucial. Commonly used methods for monitoring energy storage batteries include lithium battery voltage monitoring and temperature monitoring. Voltage monitoring involves collecting voltage data from the battery module and assessing voltage changes to determine the risk of thermal runaway. Temperature monitoring typically involves placing single or multiple temperature sensors on the aluminum busbars of the battery module to obtain temperature information during operation and then using this information to assess the risk of thermal runaway.

[0003] However, batteries typically have a multi-layered wound or stacked structure inside, and with external packaging, once internal failure warning signals such as lithium plating occur, the temperature transmission to the external aluminum busbar has a certain degree of distortion and lag. This causes the external temperature sensor to be unable to respond to lithium battery failures in a timely manner, meaning that thermal runaway has a certain degree of lag. Utility Model Content

[0004] In order to overcome the shortcomings of the existing technology, the purpose of this utility model is to provide a battery pack thermal runaway safety detection device with the advantages of being able to detect thermal runaway at an extremely early stage, improving detection accuracy and safety.

[0005] The objective of this utility model is achieved through the following technical solution:

[0006] According to an embodiment of this disclosure, a safety detection device for very early battery pack thermal runaway is provided, comprising:

[0007] Several control boards for communication with the BMS system, wherein the control boards are provided with connection plugs at positions adjacent to each battery cell;

[0008] A plurality of detection sensors disposed between two adjacent battery cells and electrically connected to the connecting plug are used to detect the expansion pressure generated by the battery cells and to feed back the pressure detection value to the BMS system; and

[0009] Conductive connectors used for electrically connecting the control board and the battery cell;

[0010] The detection sensor includes: a plurality of flexible pressure sensors and pressure bearing plates attached to both sides of the flexible pressure sensors;

[0011] The flexible pressure sensor includes a sensing part and a feedback part. The sensing part is used to receive the pressure of the pressure plate to form a pressure detection value, and the feedback part is used to connect to the battery control system to provide feedback on the pressure detection value.

[0012] The pressure plate is attached to the sensing part.

[0013] To achieve the above technical solution, the control board is electrically connected to the battery cell via a conductive connector, allowing the battery cell to supply power to the conductive connector and collect the battery cell's operating parameters. The detection sensor is electrically connected to the connector, and the collected data is fed back to the control board for processing, and finally fed back to the BMS system by the control board. In use, the detection sensor is placed between two adjacent battery cells in the battery pack, with both sides of the sensor tightly fitted to the sides of the two adjacent cells. At this time, the pressure generated by the expansion of the battery cell due to thermal runaway during operation will act on the sides of the detection sensor. Because the pressure plate is fitted to the side of the battery cell, if any abnormality occurs at any position of the battery cell... During thermal runaway expansion, pressure is applied to the pressure plate, which in turn applies pressure to the flexible pressure sensor. The sensing part of the flexible pressure sensor detects the pressure in real time and obtains the pressure value, which is then fed back to the BMS system via the feedback part. Once the pressure value exceeds the predetermined pressure threshold, it can be determined that the battery cell is about to experience thermal runaway, so that an alarm can be triggered in time. Since abnormal expansion of the battery cell is an initial phenomenon of thermal runaway, detecting the expansion pressure can achieve very early warning of thermal runaway. Moreover, the flexible pressure sensor can accurately and effectively reflect the changes in the expansion force of the battery cell, greatly improving the accuracy and safety of battery cell thermal runaway detection.

[0014] In some exemplary embodiments, the sensing part extends close to the middle of the pressure plate and corresponds to the middle of the battery cell, and the end of the feedback part is provided with a connection terminal for electrical connection with a connector plug.

[0015] The above technical solution enables more effective and accurate detection of cell expansion force, and facilitates electrical connection with the battery control system through the connection terminals.

[0016] In some exemplary embodiments, the pressure plate can cover the side of the battery cell, and the pressure plate is one of a ceramic sheet, a glass sheet, and a mica sheet.

[0017] By implementing the above technical solution, pressure will be collected when abnormal thermal runaway expansion occurs at any location in the battery cell, acting on the pressure plate.

[0018] In some exemplary embodiments, an encapsulation sheet is also provided outside the pressure-bearing sheet for integrally encapsulating the flexible pressure sensor and the pressure-bearing sheet. The encapsulation sheet is a flexible thin film material and is heat-pressed onto the outside of the pressure-bearing sheet.

[0019] The outer side of the encapsulation sheet is provided with an adhesive backing layer for bonding and fixing to the side of the battery cell.

[0020] To achieve the above technical solution, an integrated encapsulation is performed using an encapsulation sheet with an adhesive backing layer, which facilitates the bonding and fixing of the detection sensor to the side of the battery cell, simplifying the installation process.

[0021] In some exemplary embodiments, a busbar is also included, the busbar comprising a plurality of aluminum plates respectively configured to correspond to the positive / negative terminals of each battery cell to realize the series connection of each battery cell, and the conductive connector is electrically connected to the aluminum plates.

[0022] To achieve the above technical solution, a conductive connector is electrically connected to a busbar. Since the busbar enables series connection of each battery cell, when the conductive connector forms a busbar and is electrically connected to the control board, the battery cells can be monitored.

[0023] 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. Each detection slot is provided with a detection block. The detection block is connected to the control board by a rigid micro-connection structure so that the detection block is suspended in the detection slot. The micro-connection structure is provided with detection feet. The detection block can withstand the impact force of the safety valve opening so that the micro-connection structure and the detection feet break to form a breakage detection signal.

[0024] To achieve the above technical solution, when the control board is assembled onto the battery pack, the detection block corresponds to the safety valve and is located directly above it. When the detection sensor malfunctions, or when the detection sensor issues a thermal runaway alarm but is not addressed by the supervisor until the thermal runaway limit is reached, the cell expansion will cause the safety valve to open. The safety valve core will then generate an upward impact force, which will act on the detection block. The detection block will deform upward under the impact force, causing the micro-connection structure and detection support to break, generating a breakage detection signal. This detection signal is the battery pack safety valve opening signal, realizing the safety valve opening detection, further expanding the alarm method, and improving the safety of the detection.

[0025] 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 grooves adapted to the control board and a plurality of positioning grooves adapted to the aluminum foil. The control board is embedded in the fixing groove to form a predetermined distance between it and the safety valve, and the fixing groove is provided with an opening corresponding to each safety valve.

[0026] To achieve the above technical solution, the base plate facilitates the installation and fixing of the control board and aluminum plate, and enables the positioning of the control board and aluminum plate so as to make conductive connection through conductive connectors. The base plate also limits the control board to form a predetermined distance between it and the safety valve. The opening is provided to allow the impact detection block to pass through when the safety valve is opened.

[0027] In summary, compared with the prior art, this utility model has the following beneficial effects:

[0028] This utility model embodiment provides a safety detection device for early-stage thermal runaway in battery packs. The control board is electrically connected to the battery cells via conductive connectors, allowing the battery cells to supply power to the conductive connectors and collect the cell's operating parameters. A detection sensor is electrically connected to the connector, and the collected data is fed back to the control board for processing, and finally fed back to the BMS system. In use, the detection sensor is placed between two adjacent battery cells in the battery pack, with both sides of the sensor in close contact with the sides of the two adjacent cells. At this time, the pressure generated by the expansion of the battery cells due to thermal runaway during operation will act on the sides of the detection sensor. Because the pressure plate is attached to the sides of the battery cells... When abnormal thermal runaway expansion occurs at any location within the battery cell, it will act on the pressure plate, thereby applying pressure to the flexible pressure sensor. The sensing part of the flexible pressure sensor detects the pressure in real time and obtains the pressure value, which is then fed back to the BMS system via the feedback part. Once the pressure value exceeds a predetermined pressure threshold, it can be determined that the battery cell is about to experience thermal runaway, so that an alarm can be triggered in time. Since abnormal expansion of the battery cell is an initial phenomenon of thermal runaway, detecting the expansion pressure can achieve very early warning of thermal runaway. Furthermore, the flexible pressure sensor can accurately and effectively reflect the changes in the expansion force of the battery cell, greatly improving the accuracy and safety of battery cell thermal runaway detection. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the early-stage battery pack thermal runaway safety detection device in this embodiment of the present invention.

[0030] Figure 2 This is an explosion diagram of the early-stage battery pack thermal runaway safety detection device in an embodiment of this utility model.

[0031] Figure 3 for Figure 2 Enlarged view of part A in the image.

[0032] Figure 4 This is an exploded schematic diagram of the detection sensor in an embodiment of this utility model.

[0033] Figure 5 This is a schematic diagram of the arrangement of the detection legs in an embodiment of this utility model.

[0034] The numbers and letters in the diagram represent the names of the corresponding components:

[0035] 10. Control board; 11. Connector plug; 12. Detection slot; 13. Detection block; 131. Micro-connection structure; 132. Detection foot; 20. Detection sensor; 21. Flexible pressure sensor; 211. Sensing part; 212. Feedback part; 213. Connecting terminal; 22. Pressure bearing plate; 23. Encapsulation plate; 231. Adhesive backing layer; 30. Conductive connector; 40. Busbar; 41. Aluminum bar sheet; 50. Substrate; 51. Fixing slot; 52. Positioning slot; 53. Through port; 60. Battery cell. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0037] like Figures 1 to 5 As shown, the first aspect of this utility model provides a safety detection device for early thermal runaway of a battery pack, comprising: a plurality of control boards 10 for communication connection with a BMS system, wherein the control boards 10 are provided with connecting plugs 11 at adjacent positions corresponding to each battery cell 60; a plurality of detection sensors 20 disposed between two adjacent battery cells 60 and electrically connected to the connecting plugs 11 for detecting the expansion pressure generated by the battery cell 60 and feeding back the pressure detection value to the BMS system; and conductive connectors 30 for electrically connecting the control boards 10 and the battery cells 60.

[0038] 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 a flexible circuit board or a PCB circuit board, preferably a PCB circuit board to significantly reduce costs. A BMS acquisition chip is usually set on the control board 10 to realize centralized data acquisition or processing, and to communicate with the BMS system to realize data uploading.

[0039] The detection sensor 20 includes: a plurality of flexible pressure sensors 21, and pressure bearing plates 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 plate 22 to form a pressure detection value, and the feedback part 212 is used to connect to the battery control system to provide feedback on the pressure detection value; the pressure bearing plate 22 is attached to the sensing part 211.

[0040] The flexible pressure sensor 21 is an electrical device whose resistance decreases as the pressure applied to the pressure-sensitive area increases. It detects pressure by sensing changes in pressure within the pressure-sensitive area, generating changes in resistance, and then using these changes in electrical signals. This flexible pressure sensor 21 is composed of a high-performance polymer pressure-sensitive material and a highly weather-resistant thin-film encapsulation material, exhibiting excellent temperature resistance, sensitivity, and creep resistance. Compared to other pressure sensors, this flexible pressure sensor 21 has significant advantages in linearity, hysteresis, drift, and sensitivity.

[0041] The flexible pressure sensor 21 includes a sensing part 211 and a feedback part 212. The sensing part 211 is the pressure-sensitive area mentioned above. The sensing part 211 is used to receive the pressure of the pressure plate 22 to form a pressure detection value. The feedback part 212 is used to connect to the battery control system to provide feedback on the pressure detection value. The sensing part 211 extends close to the middle of the pressure plate 22 and corresponds to the middle of the cell 60. Since the cell 60 usually expands and deforms from the middle, placing the sensing part 211 in the middle position can more effectively and accurately detect the expansion force of the cell 60. The end of the feedback part 212 is provided with a connection terminal 213. The connection terminal 213 can be, for example, a conductive connector, a conductive connecting piece, or the like. Correspondingly, the connection plug 11 is an interface that is adapted to the connection terminal 213 to facilitate electrical connection with the battery control system.

[0042] The pressure plate 22 is attached to the sensing part 211, and the pressure plate 22 can cover the side of the battery cell 60. The size and shape of the pressure plate 22 are usually consistent with the side of the battery cell 60. The pressure plate 22 is one of ceramic sheet, glass sheet and mica sheet. Preferably, the pressure plate 22 is made of mica sheet.

[0043] An encapsulation sheet 23 is also provided outside the pressure plate 22 to encapsulate the flexible pressure sensor 21 and the pressure plate 22 as a whole. The encapsulation sheet 23 is a flexible thin film material and is heat-pressed onto the outside of the pressure plate 22. During the heat-pressing process, the flexible film encapsulates the pressure plate 22 and the flexible pressure sensor 21 in a wrapped manner. An adhesive backing layer 231 is provided on the outside of the encapsulation sheet 23. The adhesive backing layer 231 is used to bond and fix it to the side of the battery cell 60, so as to bond and fix the detection sensor 20 to the side of the battery cell 60 and simplify the installation process. In some embodiments, a release layer can also be provided outside the adhesive backing layer 231 to prevent the detection sensor 20 from sticking to other items when not installed. When installing, the release layer can be removed to bond and fix it to the battery cell 60.

[0044] In use, the detection sensor 20 is simultaneously bonded and fixed to the sides of two adjacent battery cells 60 through the adhesive backing layer 231, thus realizing the installation of the detection sensor 20. Preferably, a sensor is set between each adjacent battery cell 60. In some embodiments, every two battery cells 60 can be grouped together, and a detection sensor 20 is set between the two battery cells 60 in each group, while no detection sensor 20 is set between adjacent groups. This setting method can reduce the number of sensors used, but the corresponding detection effect will also be weakened.

[0045] In practical applications, two or more sets of detection sensors 20 can be set between two adjacent cells 60, for example, 2-6 sets. The sensing parts 211 of each set of detection sensors 20 are linearly or arrayed. Of course, in some embodiments, multiple sensing parts 211 can be set on the detection sensor 20. The multiple sensing parts 211 can also be linearly or arrayed, thereby forming a more accurate and effective pressure detection.

[0046] Furthermore, the device also includes a busbar 40, which includes several aluminum strips 41 respectively configured to correspond to the positive / negative terminals of each battery cell 60 to achieve series connection of the battery cells 60. A conductive connector 30 is electrically connected to the aluminum strips 41. The conductive connector 30 can use an existing structure. Since the busbar 40 achieves series connection of the battery cells 60, when the conductive connector 30 forms a busbar 40 that is electrically connected to the control board 10, monitoring of the battery cells 60 can be achieved.

[0047] Furthermore, the control board 10 is also provided with a number of detection slots 12 corresponding to the safety valves of each battery cell 60. Each detection slot 12 is provided with a detection block 13. The detection block 13 is connected to the control board 10 by a rigid micro-connection structure 131 so that the detection block 13 is suspended in the detection slot 12. The micro-connection structure 131 is provided with detection feet 132. The detection block 13 can withstand the impact force of the safety valve opening so that the micro-connection structure 131 and the detection feet 132 break to form a breakage detection signal.

[0048] The detection block 13 can be set as a rectangle, ellipse, circle, polygon, or any combination of shapes. The micro-connection structure 131 is set on one side outside the detection. The detection pin 132 can specifically 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 pin is broken, the resistance value of the detection circuit is changed 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 to the detection resistor. Under normal circumstances, the detection resistor is connected in parallel in 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, thereby causing the resistance value of the entire detection circuit to change. The detection circuit detects the change in electrical signal and forms a detection signal, determines that the safety valve is open, and completes the valve opening detection.

[0049] When the control board 10 is assembled onto the battery pack, the detection block 13 corresponds to the safety valve and is located directly above it. When the detection sensor 20 malfunctions, or when the detection sensor 20 issues a thermal runaway alarm but is not addressed by the supervisor until the thermal runaway limit is reached, the expansion of the battery cell 60 will cause the safety valve to open. The safety valve core will then generate an upward impact force, which will act on the detection block 13. The detection block 13 will deform upward under the impact force, causing the micro-connection structure 131 and the detection support 132 to break, generating a breakage detection signal. This detection signal is the battery pack safety valve opening signal, realizing the safety valve opening detection, further expanding the alarm method, and improving the safety of the detection.

[0050] For ease of assembly, a base plate 50 is fixed to the top of the battery pack. The base plate 50 is made of insulating material. The base plate 50 has several fixing grooves 51 that are adapted to the control board 10 and several positioning grooves 52 that are adapted to the aluminum bar sheet 41. Of course, in order to facilitate the installation of the detection sensor 20, holes for the detection sensor 20 to pass through are also provided on the control board 10. The control board 10 is embedded in the fixing groove 51 to form a predetermined distance with the safety valve, and the fixing groove 51 has a through-hole 53 corresponding to each safety valve. In some embodiments, an explosion-proof film can also be provided above the base plate 50. The explosion-proof film covers the control board 10 and the busbar 40, and the explosion-proof film also has a through-hole 53 corresponding to the detection groove 12 for the detection block 13 to be bent.

[0051] The base plate 50 facilitates the installation and fixing of the control board 10 and the aluminum bar 41, and enables the positioning of the control board 10 and the aluminum bar 41 so as to make a conductive connection through the conductive connector 30. The base plate 50 restricts the control board 10 and the safety valve to form a predetermined distance. The opening 53 is provided to allow the impact detection block 13 to pass through when the safety valve is opened.

[0052] In this invention, the control board 10 is electrically connected to the battery cell 60 via the conductive connector 30, thereby enabling the battery cell 60 to supply power to the conductive connector 30 and collect the operating parameters of the battery cell 60. The detection sensor 20 is electrically connected to the connector plug 11, allowing the collected data to be fed back to the control board 10 for processing, and finally fed back to the BMS system by the control board 10. In use, the detection sensor 20 is placed between two adjacent battery cells 60 in the battery pack, with both sides of the detection sensor 20 tightly attached to the sides of the two adjacent 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 sides of the detection sensor 20. Since the pressure plate 22 is attached to the side of the battery cell 60, when the battery cell 60 is in any position... When abnormal thermal runaway expansion occurs at a certain location, it will act on the pressure plate 22, thereby applying pressure to the flexible pressure sensor 21. The sensing part 211 of the flexible pressure sensor 21 detects the pressure in real time and obtains the pressure detection value, which is fed back to the BMS system through the feedback part 212. Once the pressure detection value exceeds the predetermined pressure threshold, it can be determined that the battery cell 60 is about to experience thermal runaway, so as to issue an alarm in time. Since abnormal expansion of the battery cell 60 is an initial phenomenon of thermal runaway, detecting the expansion pressure can achieve very early thermal runaway warning. Moreover, the flexible pressure sensor 21 can accurately and effectively reflect the changes in the expansion force of the battery cell 60, greatly improving the accuracy and safety of thermal runaway detection of the battery cell 60.

[0053] The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model 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 this utility model. These are all equivalent modifications and improvements made to the above embodiments based on the essential technology of this utility model, and all of these fall within the protection scope of this utility model.

Claims

1. A safety detection device for very early battery pack thermal runaway, characterized in that, include: Several control boards for communication with the BMS system, wherein the control boards are provided with connection plugs at positions adjacent to each battery cell; Several detection sensors disposed between two adjacent battery cells and electrically connected to the connecting plug are used to detect the expansion pressure generated by the battery cells and to feed back the pressure detection value to the BMS system. as well as, Conductive connectors used for electrically connecting the control board and the battery cell; The detection sensor includes: a plurality of flexible pressure sensors and pressure bearing plates 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 plate to form a pressure detection value, and the feedback part is used to connect to the battery control system to provide feedback on the pressure detection value. The pressure plate is attached to the sensing part.

2. The early-stage battery pack thermal runaway safety detection device according to claim 1, characterized in that, The sensing part extends close to the middle of the pressure plate and corresponds to the middle of the battery cell. The end of the feedback part is provided with a connection terminal, which is used for electrical connection with the connector plug.

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

4. The early-stage battery pack thermal runaway safety detection device according to claim 3, characterized in that, The pressure-bearing sheet is also provided with an encapsulation sheet, which is used to encapsulate the flexible pressure sensor and the pressure-bearing sheet together. The encapsulation sheet is a flexible thin film material and is heat-pressed onto the outside of the pressure-bearing sheet. The outer side of the encapsulation sheet is provided with an adhesive backing layer for bonding and 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 also includes a busbar, which includes several aluminum bars that are respectively arranged to correspond to the positive / negative poles of each battery cell to realize the series connection of each battery cell, and the conductive connector is electrically connected to the aluminum bars.

6. The early-stage battery pack thermal runaway safety detection device according to claim 1, characterized in that, The control board is also provided with several detection slots corresponding to the safety valves of each battery cell. Each detection slot is provided with a detection block. The detection block is connected to the control board by a rigid micro-connection structure so that the detection block is suspended in the detection slot. The micro-connection structure is provided with detection feet. The detection block can withstand the impact force of the safety valve opening so that the micro-connection structure and the detection feet break to form a breakage detection signal.

7. The early-stage battery pack thermal runaway 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 has several fixing grooves adapted to the control board and multiple positioning grooves adapted to the aluminum foil. The control board is embedded in the fixing groove to form a predetermined distance with the safety valve, and the fixing groove has a through port corresponding to each safety valve.

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