Lithium ion battery module thermal runaway early warning and prevention and control system and method

Abstract

The invention discloses a lithium ion battery module thermal runaway early warning, prevention and control system and method, belongs to the technical field of lithium battery safety, and aims to solve the problems of response lag and limited prevention and control effect in the prior art. The thermal runaway early warning and prevention and control system comprises a data acquisition module, a judgment module, a positioning module, an early warning module, a trigger module and a state monitoring device. According to the early warning and prevention and control method, the overall expansion force of each column of lithium batteries is monitored in real time, an abnormal state is identified and positioned, and an early warning mechanism is triggered; and meanwhile, a forced cooling and discharging program aiming at the abnormal column is automatically started. According to the invention, early warning of expansion force and a cooling and discharging cooperative prevention and control strategy are combined, multiple columns of lithium battery modules are adapted, long-term stability of monitoring is ensured, heat spreading can be quickly and accurately blocked, the safety of the battery modules is improved, and the accident rate and the excessive prevention and control cost are reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium battery safety, in particular to a lithium ion battery module thermal runaway early warning and prevention system and method. BACKGROUND

[0002] With the rapid development of new energy vehicles, large-scale battery energy storage and other fields, lithium ion batteries have become the core energy storage components in the above-mentioned fields due to their high energy density, long cycle life, high charging and discharging efficiency, and high integration rate. Their application scale and scenarios continue to expand, which is of great significance to ensure the efficient and stable operation of related industries.

[0003] However, during long-term charging and discharging cycles, harsh operating conditions or abnormal use, lithium ion batteries are prone to trigger internal violent chain redox reactions due to electrical abuse, mechanical abuse or thermal abuse; this reaction can release a large amount of heat and flammable gas in a short time, not only causing a single battery to appear thermal runaway, but also transferring heat to adjacent batteries through heat conduction, heat radiation and gas injection, etc., causing a chain reaction of heat spread phenomenon. Such problems can directly damage the structural integrity of the battery module and even the entire battery system, and in severe cases, can cause fires, explosions and other safety accidents, posing a major threat to user life and property safety and equipment operation safety, and has become a key bottleneck restricting the further popularization and application of lithium ion batteries in high safety demand fields.

[0004] In view of the above-mentioned thermal runaway and heat spread problems, there are mainly two types of prevention and control means in the prior art: one is to reduce the overall temperature of the battery module through an external cooling system to delay the triggering process of thermal runaway; the other is to set physical isolation between batteries to try to block the heat spread path. However, practice shows that the external cooling system lags behind in response to the local thermal runaway triggered battery, and is difficult to quickly suppress the internal violent exothermic reaction; and the physical isolation can only weaken the heat transfer efficiency to a certain extent, and cannot completely prevent the spread of high-temperature gas and flame, especially under the trend of increasing integration of battery modules, the prevention and control effect of the existing technology is increasingly limited, and it is difficult to meet the high safety standard requirements in actual application.

[0005] Therefore, how to propose a method with fast response speed and high prevention and control precision, which can not only effectively early warn the thermal runaway risk of lithium ion batteries, but also block the heat spread chain from the source, has become a core technical problem that needs to be solved in the current lithium ion battery module safety technology field. SUMMARY

[0006] Based on the above description, the present application provides a lithium ion battery module thermal runaway early warning and prevention system and method, which solves the problems of late response of existing lithium ion battery module thermal runaway early warning, insufficient abnormal positioning precision, and weak pertinence of prevention and control measures.

[0007] The technical scheme for solving the above technical problems of the present application is as follows:

[0008] A lithium ion battery module thermal runaway early warning and prevention system, comprising a data acquisition module, a judgment module, a positioning module, a warning module, a triggering module, and a state monitoring device.

[0009] The data acquisition module is used to acquire the overall expansion force data of each column of lithium batteries and provide raw data for the judgment module.

[0010] The judgment module is used to output corresponding judgment results according to the relationship between the data transmitted by the data acquisition module and the preset threshold.

[0011] The positioning module is used to determine the position of the abnormal lithium battery column according to the judgment result of the judgment module.

[0012] The warning module is used to issue a warning signal according to the judgment result of the judgment module.

[0013] The triggering module is used to trigger the thermal runaway prevention program according to the result of the judgment module and the position information of the positioning module.

[0014] The state monitoring device is a hardware used to support system state data acquisition, including a box, an adjusting screw, a force sensor, and a moving steel plate.

[0015] Further, the box of the state monitoring device can accommodate multiple columns of lithium batteries, each column containing several single lithium batteries, forming a modular layout.

[0016] Further, the force sensor of the state monitoring device is installed corresponding to the adjusting screw, and a plurality of force sensors are installed on one side of the state monitoring device, one force sensor corresponding to one column of lithium batteries, for accurately measuring the overall expansion force of the corresponding column; a plurality of adjusting screws are installed on the other side of the state monitoring device, and the overall pre-tightening force of the lithium battery column is adjusted by rotating the adjusting screw, ensuring that the force sensor is always in an effective monitoring state.

[0017] Further, the moving steel plate of the state monitoring device is placed on both sides of each column of lithium batteries, isolating the lithium batteries from the force sensor and the front end of the adjusting screw, avoiding measurement errors or structural damage caused by direct contact, and improving the reliability of the monitoring data.

[0018] Further, the adjusting screw of the state monitoring device cooperates with the force sensor, which can offset the expansion attenuation of the lithium battery during long-term use by dynamically adjusting the pre-tightening force, ensuring the long-term stability of the expansion force monitoring.

[0019] Preferably, the judging module determines whether the overall expansion force of a certain column is greater than a preset expansion force threshold to obtain a judgment result of the abnormal lithium battery column; if the overall expansion force is greater than the preset expansion force threshold, the judgment result is abnormal, and vice versa.

[0020] Preferably, the positioning module receives the judgment result of the judging module, locates the abnormal lithium battery column, and transmits the position information to the triggering module in real time.

[0021] Preferably, the warning module receives the judgment result of the judging module, and sends a warning signal if an abnormal judgment result is received.

[0022] Preferably, the triggering module needs to receive the judgment result of the judging module and the position information of the abnormal battery column of the positioning module before triggering the thermal runaway prevention and control program; if an abnormal judgment result is received, the triggering module will start the program of forcibly cooling the abnormal lithium battery column and the discharge program of the abnormal lithium battery column to cooperatively suppress thermal runaway.

[0023] The application also provides a lithium ion battery module thermal runaway early warning and prevention method, which is characterized by being applied to the lithium ion battery module thermal runaway early warning and prevention system.

[0024] Step 1: The data acquisition module of the system collects the overall expansion force data of each column of lithium batteries in real time.

[0025] Step 2: The judging module of the system judges whether the lithium battery is abnormal, and locates the abnormal lithium battery column through the positioning module.

[0026] Step 3: According to the judgment result of the judging module of the system, the warning module is driven to send a warning signal or not.

[0027] Step 4: According to the judgment result of the judging module of the system and the position information of the abnormal lithium battery column transmitted by the positioning module, the triggering module is driven to start the program of forcibly cooling the abnormal lithium battery column and the discharge program of the abnormal lithium battery column or not.

[0028] Preferably, in step 2, when the overall expansion force of a certain column of lithium batteries exceeds the preset expansion force threshold, the system determines that the column is an abnormal lithium battery column, and locates the column of lithium batteries.

[0029] Preferably, in step 3, the warning module sends a warning signal if an abnormal judgment result is received.

[0030] Preferably, in step 4, if the triggering module receives an abnormal judgment result, the program of forcibly cooling the abnormal lithium battery column and the discharge program of the abnormal lithium battery column are started.

[0031] Compared with the prior art, the application has the advantages that early warning of expansion force is combined, and cooling and grouping positioning discharge are cooperated to efficiently inhibit thermal runaway and block heat spread; the application can be adapted to multiple columns and multiple rows of lithium battery modules, and has strong flexibility in structure and logic; a control system of multiple modules is cooperated to improve the response speed of early warning and prevention and control, the operation safety of the lithium battery module is significantly improved, the incidence of thermal runaway accidents is reduced, and energy consumption and maintenance cost caused by excessive prevention and control are reduced. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 A module connection schematic diagram of a specific embodiment of a lithium ion battery module thermal runaway early warning and prevention system provided by the application is shown in the figure.

[0033] Figure 2 A structure schematic diagram of a specific embodiment of a state monitoring device of a lithium ion battery module thermal runaway early warning and prevention system provided by the application is shown in the figure.

[0034] In all the above figures: 1, box, 2, adjusting screw rod, 3, force sensor, 4, moving steel plate, 5, single lithium battery. DETAILED DESCRIPTION

[0035] In the description of the application, it should be noted that the directions or position relationships indicated by the terms "left", "right" and the like are based on the directions or position relationships shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0036] Any obvious improvement, replacement or modification made by those skilled in the art on the basis of the application belongs to the protection scope of the application. In addition, although some specific terms are used in the specification, these terms are only for convenience of description and do not constitute any limitation on the application.

[0037] The principles and characteristics of the application are described below in combination with the drawings, and the examples are only used to explain the application and do not limit the scope of the application.

[0038] As Figure 1 shown:

[0039] To reduce the complexity of the thermal runaway early warning and prevention system and improve its flexibility and maintainability, the functions of a lithium ion battery module thermal runaway early warning and prevention system are modularly designed. The main modules in the system include: a data acquisition module for acquiring the overall swelling force data of each column of lithium batteries to provide raw data for the judgment module; a judgment module for outputting the corresponding judgment result according to the relationship between the data transmitted by the data acquisition module and the preset threshold; a positioning module for determining the position of the abnormal lithium battery column according to the judgment result of the judgment module; a warning module for issuing a warning signal according to the judgment result of the judgment module; and a triggering module for triggering the thermal runaway prevention program according to the result of the judgment module and the position information of the positioning module.

[0040] As shown in Figure 2

[0041] To efficiently implement the lithium ion battery module thermal runaway early warning and prevention method, a state monitoring device of a lithium ion battery module thermal runaway early warning and prevention system is used to support the acquisition of system state data. The state monitoring device mainly includes a box (1), an adjusting screw (2), a force sensor (3), and a moving steel plate (4). The box (1) can accommodate multiple columns of lithium batteries, each column containing several single lithium batteries (5), forming a modular layout. The force sensor (3) is installed corresponding to the adjusting screw (2). On one side of the device, several force sensors (3) are installed, one force sensor (3) corresponding to one column of lithium batteries. On the other side of the device, several adjusting screws (2) are installed corresponding. The overall pre-tightening force of the lithium battery column is adjusted by rotating the adjusting screw (2). The moving steel plate (4) is placed on both sides of each column of lithium batteries, isolating the lithium batteries from the force sensor (3) and the front end of the adjusting screw (2) to avoid measurement errors or structural damage caused by direct contact.

[0042] To offset the monitoring deviation caused by physical state changes during long-term use of lithium batteries and ensure the long-term stability of the swelling force data, the adjusting screw (2) and the force sensor (3) in the device are installed in coordination. On one side of the device, several force sensors (3) are installed, one force sensor (3) corresponding to one column of lithium batteries, for real-time acquisition of the overall swelling force of each column of lithium batteries. On the other side of the device, several adjusting screws (2) are installed corresponding. The front end of the screw is attached to the side of the moving steel plate (4). By rotating the screw, the pre-tightening force of the corresponding lithium battery column can be dynamically adjusted, thereby offsetting the problem of loose attachment of the force sensor (3) due to physical state changes after long-term use of lithium batteries, and ensuring that the swelling force monitoring data is always within the accurate range.

[0043] ​To realize flexible assembly of lithium battery module and convenience of later maintenance, the box (1) adopts modular layout design; a plurality of lithium battery installation spaces are reserved in the box (1), each space can accommodate a plurality of single lithium batteries (5), each column is independently partitioned and the assembly size is uniform, which is convenient for adjusting the number of columns and the number of single lithium batteries (5) in each column according to actual needs, and simultaneously simplifies the operation process of replacing single lithium batteries (5) or overhauling lithium battery column in later period.

[0044] To ensure the stable operation of the whole thermal runaway early warning and prevention system, a lithium ion battery module thermal runaway early warning and prevention method includes four steps: step 1, through the data acquisition module of the system, the total expansion force data of each column of lithium batteries is collected in real time; step 2, through the judgment module of the system, whether the lithium battery works abnormally is judged, and the abnormal lithium battery column is located through the positioning module; step 3, according to the judgment result of the system judgment module, whether the warning module sends an alarm signal is driven; step 4, according to the judgment result of the system judgment module and the position information of the abnormal lithium battery column transmitted by the positioning module, whether the triggering module starts the program of forcibly cooling the abnormal lithium battery column and the discharge program of the abnormal lithium battery column.

[0045] In step 2, when the total expansion force of a column of lithium batteries exceeds the preset expansion force threshold, the system determines that the column is an abnormal lithium battery column, and the column of lithium batteries is located.

[0046] In step 3, if the warning module receives the abnormal judgment result, an alarm signal is sent.

[0047] In step 4, if the triggering module receives the abnormal judgment result, the program of forcibly cooling the abnormal lithium battery column and the discharge program of the abnormal lithium battery column are started.

[0048] This method can identify the abnormal state of the lithium battery column in advance by monitoring the expansion force signal, and simultaneously start the forced cooling measure to reduce the temperature of the lithium battery and reduce the risk of thermal runaway, so as to gain more time for accident disposal. Further, by cooperatively implementing the active discharge treatment of the abnormal battery column, the state of charge of the lithium battery can be significantly reduced, the threshold of the thermal runaway triggering temperature can be improved, and the releasable battery energy can be reduced, thereby fundamentally inhibiting the trend of thermal runaway and heat spread. Among them, the forced cooling provides a key time window for reducing the state of charge of the target battery in the active discharge process, forming a synergistic inhibition effect of "thermal-electric" time sequence coupling. In addition, the active discharge of the abnormal battery column can simplify the discharge circuit on the one hand, and can use the discharged electricity to provide energy for the forced cooling system on the other hand, thereby reducing additional energy dissipation.

[0049] The above merely describes preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A lithium-ion battery module thermal runaway early warning and prevention system, characterized in that: It includes a data acquisition module, a judgment module, a positioning module, an early warning module, a triggering module, and a status monitoring device; The data acquisition module is used to acquire the total expansion force data of each column of lithium batteries, providing raw data for the judgment module; The judgment module is used to output a corresponding judgment result based on the relationship between the data transmitted by the data acquisition module and the preset threshold. The positioning module is used to determine the location of the abnormal lithium battery array based on the judgment result of the judgment module; The early warning module is used to issue a warning signal based on the judgment result of the judgment module; The triggering module is used to trigger the thermal runaway prevention and control program based on the result of the judgment module and the location information of the positioning module; The status monitoring device is hardware used to support the acquisition of system status data, including a housing (1), an adjusting screw (2), a force sensor (3), and a moving steel plate (4).

2. The lithium-ion battery module thermal runaway early warning and prevention system according to claim 1, characterized in that: The housing (1) of the status monitoring device can hold multiple rows of lithium batteries, each row containing several individual lithium batteries (5), forming a modular layout; The force sensor (3) of the state monitoring device is installed in correspondence with the adjusting screw (2). Several force sensors (3) are installed on one side of the state monitoring device, and one force sensor (3) corresponds to one column of lithium batteries. Several adjusting screws (2) are installed on the other side of the state monitoring device. The overall preload is adjusted by rotating the adjusting screw (2) to press the lithium battery column. The movable steel plate (4) of the condition monitoring device is placed on both sides of each row of lithium batteries, isolating the lithium batteries from the force sensor (3) and the front end of the adjusting screw (2) to avoid measurement errors or structural damage caused by direct contact. The judgment module determines the abnormal lithium battery column judgment result based on whether the total expansion force of a column is greater than a preset expansion force threshold; if the total expansion force is greater than the preset expansion force threshold, the judgment result is abnormal, otherwise it is normal. The positioning module receives the judgment result from the judgment module, locates the abnormal lithium battery column, and transmits the location information to the triggering module in real time. The early warning module receives the judgment result from the judgment module, and if an abnormal judgment result is received, it issues an alarm signal. Before triggering the thermal runaway prevention and control program, the triggering module needs to receive the judgment result from the judgment module and the abnormal battery column location information from the positioning module. If an abnormal judgment result is received, the triggering module will start the program for forced cooling of the abnormal lithium battery column and the discharge program of the abnormal lithium battery column to jointly suppress thermal runaway.

3. A method for early warning and prevention of thermal runaway in lithium-ion battery modules, characterized in that... The method, applied to a lithium-ion battery module thermal runaway early warning and prevention system as described in any one of claims 1-2, comprises the following steps: Step 1: Collect the overall expansion force data of each row of lithium batteries in real time through the system's data acquisition module; Step 2: The system's judgment module determines whether the lithium battery is malfunctioning, and the positioning module locates the abnormal lithium battery cluster. Step 3: Based on the judgment result of the system judgment module, drive the early warning module to issue a warning signal; Step 4: Based on the system judgment module and the judgment result, as well as the abnormal lithium battery column location information transmitted by the positioning module, drive the trigger module to start the program for forced cooling of the abnormal lithium battery column and the discharge program of the abnormal lithium battery column. In step 2, when the total expansion force of a certain column of lithium batteries exceeds the preset expansion force threshold, the system determines that the column is an abnormal lithium battery column and locates the lithium batteries in that column. In step 3, if the early warning module receives an abnormal judgment result, it will issue an alarm signal. In step 4, if the trigger module receives the abnormal judgment result, it starts the program for forced cooling of the abnormal lithium battery column and the discharge program of the abnormal lithium battery column.

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