Lithium battery thermal runaway control and safety response strategy system

Abstract

The invention discloses a lithium battery thermal runaway control and safety response strategy system, which realizes the real-time monitoring and prediction of the internal temperature and voltage state of a battery through thermal-electric coupling modeling and multi-sensing data fusion, and realizes the real-time monitoring and prediction of the internal temperature and voltage state of the battery based on a model prediction control and threshold enhancement strategy. And triggering graded safety response in the early stage of thermal runaway. The system adopts a multi-stage response mechanism including measures of primary early warning, active cooling intervention, emergency power-off fire extinguishing and the like, a gas suppression path and cooling mode switching function is designed, and heat diffusion and spreading and toxic gas harm are effectively suppressed. Compared with a method depending on complex digital twinning or deep learning, the method is simple in structure, rapid in response and low in data dependence, has good system stability and engineering applicability, and can be widely applied to the field of lithium battery safety management of electric vehicle battery packs, energy storage power stations and the like.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery safety protection technology, specifically relating to a control and safety response strategy system for lithium battery thermal runaway. Background Technology

[0002] Lithium-ion batteries are widely used in electric vehicles, energy storage power stations, and portable electronic devices due to their high energy density and good cycle life. However, under extreme conditions such as overcharging, over-discharging, internal short circuits, and high temperatures, lithium batteries are prone to thermal runaway, which triggers violent exothermic reactions inside the battery, causing the battery temperature to rise sharply and releasing flammable and toxic gases (such as HF and CO). In severe cases, this can cause the battery to catch fire and explode, endangering personal and equipment safety.

[0003] Existing battery management systems (BMS) and safety protection devices mostly employ passive protection mechanisms: they typically only trigger power-off, cooling, or fire suppression measures after the battery temperature reaches a fixed threshold. This simple threshold control method suffers from response lag; when action is taken only after the battery temperature has climbed close to the critical point, it is often too late to prevent thermal runaway in time. Furthermore, traditional devices lack effective means to handle the large amounts of toxic gases generated by thermal runaway, usually relying solely on natural venting through the battery casing's pressure relief vents, which cannot prevent the spread of harmful gases and causes secondary harm to the environment and personnel.

[0004] To improve the thermal runaway protection of lithium batteries, some studies have attempted to introduce advanced prediction and control technologies. For example, some research utilizes digital twin technology to simulate the internal state of the battery in real time, or employs machine learning / deep learning models to perform big data-driven risk prediction of the battery state. However, these cutting-edge technologies often suffer from problems such as complex models, high computational load, and strong dependence on historical data, resulting in insufficient stability and reliability in real-time applications in actual battery systems. Furthermore, current battery thermal management solutions lack robust active intervention strategies (such as variable cooling intensity and graded response), and lack the ability to automatically switch control logic based on the severity of the fault.

[0005] Therefore, there is an urgent need for a method that integrates reliable modeling and prediction with rule-based control, based on existing experimental platforms, to proactively control the multi-level safety response to thermal runaway in lithium batteries. This method should achieve early warning of thermal runaway, rapid intervention cooling, suppression of heat propagation, and treatment of toxic gases, while ensuring system stability and real-time performance, thus addressing the issues of response lag and insufficient protection in existing technologies. Summary of the Invention

[0006] The purpose of this invention is to address the problems of untimely response and incomplete protection in battery thermal runaway as described in the background art, and to provide a control and safety response strategy system for lithium battery thermal runaway, so as to achieve early detection of battery thermal runaway and multi-level safety protection.

[0007] The technical solution adopted in this invention is as follows: A control and safety response strategy system for lithium battery thermal runaway, comprising: a multi-sensor monitoring module, a thermo-electric coupling modeling module, a thermal runaway risk assessment module, a safety response control module, and a safety execution module; wherein, the multi-sensor monitoring module is used to monitor the operating parameters of the lithium-ion battery, including battery temperature, voltage, current, and gas concentration inside the battery compartment, and to acquire the data of the parameters in real time; the thermo-electric coupling modeling module is used to construct a thermo-electric coupling model of the battery based on the operating parameters, to simulate and predict the internal temperature changes and voltage response of the battery, and to provide real-time estimates and short-term predictions of the battery temperature state; the thermal runaway risk assessment module, using... Based on the operating parameters and predicted values, the system identifies preset abnormal operating conditions of the battery. When the battery temperature and temperature rise rate exceed the threshold or an abnormal voltage drop trend occurs, the system determines the thermal runaway risk level. The safety response control module is used to trigger corresponding multi-level safety response strategies according to the thermal runaway risk level, and generate control commands to execute predetermined safety response measures, including cooling, power regulation, gas handling, and circuit isolation. The safety execution module includes a cooling device, a gas suppression device, a power-off device, and a fire extinguishing device, which are used to cool the battery, divert and purify harmful gases, cut off circuits, and extinguish fires at different response levels, respectively, to suppress the further expansion of thermal runaway.

[0008] In a preferred embodiment, the thermal-electric coupling modeling module uses a combination of equivalent circuit and lumped thermal model to perform joint electrical and thermal modeling of the lithium battery. The electrical model characterizes the dynamic voltage characteristics of the battery based on the RC equivalent circuit, while the thermal model characterizes the internal heat generation and dissipation process of the battery based on the thermal capacity-thermal resistance network. A bidirectional coupling is established between the electrical model and the thermal model, so that the current change and the heat generation rate, and the temperature change and the internal resistance parameter influence each other.

[0009] In a preferred embodiment, the thermal runaway risk assessment module presets multiple criteria, including a battery temperature threshold, a temperature rise rate threshold, and a voltage drop magnitude threshold. When the battery temperature or temperature rise rate exceeds the safety threshold, or when the voltage change shows an abnormal trend, it is determined to enter the corresponding thermal runaway risk condition level.

[0010] In a preferred embodiment, the cooling device has multiple cooling operating modes, including a normal cooling mode and an emergency cooling mode. When the battery temperature exceeds a first preset threshold, the normal cooling mode is activated to cool the battery. When the temperature continues to rise and exceeds a second preset threshold, the device automatically switches to the emergency cooling mode to enhance the cooling intensity. The normal cooling mode dissipates heat through a fan or liquid cooling circulation, while the emergency cooling mode rapidly suppresses the rise in battery temperature by using coolant injection or phase change material heat absorption.

[0011] In a preferred embodiment, the gas suppression device includes a battery compartment depressurization channel and a gas filtration and purification module connected to the channel. When the battery experiences thermal runaway and releases harmful gases, the channel will open under the instruction of the safety response control module to guide the gas in the battery compartment into the filtration and purification module for treatment. The filtration and purification module contains activated carbon adsorbent and catalytic conversion medium to adsorb toxic gases such as acidic gases HF and CO and convert them into harmless products, thereby reducing the concentration of harmful gases and the risk of combustion.

[0012] In a preferred embodiment, the multi-level safety response strategy includes at least three response levels: Level 1 warning, Level 2 intervention, and Level 3 emergency protection. Specifically, in Level 1 warning mode, the system issues an audible and visual alarm signal and activates the cooling device's normal cooling to control the temperature rise. In Level 2 intervention mode, the system reduces the battery's charging and discharging power output to a predetermined safety level, activates an enhanced cooling mode, and turns on the gas suppression device to extract and purify the gas inside the battery compartment. In Level 3 emergency protection mode, the system quickly disconnects the battery circuit, isolates the battery from external circuits via the power-off device, and triggers the fire extinguishing device to extinguish the fire in the battery.

[0013] In a preferred embodiment, the safety response control module employs a threshold enhancement strategy, combining dynamic parameters such as the rate of temperature rise, the rate of voltage change, and changes in gas concentration to comprehensively judge signs of thermal runaway, and dynamically adjusts the trigger threshold conditions for each response level to improve the sensitivity and accuracy of early identification of thermal runaway, and reduce the possibility of missed or false alarms that may be caused by a single fixed threshold.

[0014] In a preferred embodiment, the safety response control module combines a model predictive control algorithm to predict the temperature change trend of the battery in real time within a predetermined time period. When the prediction result shows that the battery temperature will exceed the safety threshold within the threshold time window, a control command is issued in advance to execute cooling or power limiting measures, thereby intervening and controlling before thermal runaway occurs.

[0015] In a preferred embodiment, the fire extinguishing device is an aerosol fire extinguishing system, which is installed inside the battery compartment and has multiple spray nozzles arranged towards the battery. When the battery temperature exceeds the dangerous temperature threshold or an open flame is detected, the safety response control module automatically triggers the aerosol fire extinguishing system to release the extinguishing agent instantaneously. The extinguishing agent forms uniform fine particles that are suspended around the battery, quickly covering the battery surface and suppressing the spread of the flame.

[0016] In a preferred embodiment, the following steps are included: S1 Acquiring multi-source monitoring data of the lithium battery during operation, including parameters such as battery voltage, current, temperature, and gas concentration in the battery compartment;

[0017] S2 inputs the monitoring data into the thermo-electric coupling model for calculation, and calculates the current temperature state of the battery in real time and predicts the temperature change trend in a short period of time.

[0018] S3 compares and analyzes the monitoring data and model prediction results with the preset safety threshold to determine whether the battery shows signs of thermal runaway such as abnormal temperature rise or abnormal voltage fluctuation, and determines the thermal runaway risk level accordingly.

[0019] S4 invokes the corresponding safety response strategy based on the determined thermal runaway risk level and generates control commands to execute the predetermined safety response operations.

[0020] S5 executes the control command and implements corresponding safety measures for the battery, including activating the cooling device for cooling, adjusting the charging and discharging power or cutting off the battery circuit, opening the gas suppression channel to discharge and purify harmful gases, and triggering the fire extinguishing device to extinguish the fire, so as to effectively control the battery thermal runaway state.

[0021] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0022] 1. This invention combines a thermo-electric coupling model with multi-sensor monitoring to achieve accurate detection and risk assessment of early signs of thermal runaway in lithium batteries. Compared to traditional single temperature threshold monitoring, this invention can more sensitively detect various danger signals such as sudden temperature rises and abnormal voltage changes, and initiate corresponding protective measures in advance, greatly shortening the lag time of thermal runaway response.

[0023] 2. This invention establishes a comprehensive multi-level safety response strategy: from initial early warning (alarm prompts and enhanced heat dissipation) to mid-term intervention (power-limited operation and enhanced cooling and exhaust purification) to final emergency response (power outage isolation and battery fire suppression), each level of measures is progressive yet interconnected, and can automatically switch to the optimal control strategy according to the severity of the accident. This tiered prevention and control system effectively avoids premature or delayed responses, improving the pertinence and effectiveness of safety measures.

[0024] 3. This invention features a specialized gas suppression and cooling switching mechanism that simultaneously addresses the issues of heat and harmful gases during thermal runaway. By dynamically switching cooling methods, it maintains efficient heat dissipation under normal operating conditions and rapidly cools down in emergencies, preventing the spread of thermal runaway. Furthermore, gas diversion and filtration promptly extract and purify leaked flammable and toxic gases from the battery, significantly reducing the risk of fire and poisoning. The combination of these two mechanisms comprehensively controls the cascading hazards caused by battery thermal runaway.

[0025] 4. This invention abandons complex artificial intelligence algorithms and virtual simulation systems, instead employing simplified model prediction and threshold control strategies. This ensures both the stability and reliability of the system architecture and the rapid real-time response. Without relying on massive historical data and high-performance computing, this system can achieve accurate prediction, early warning, and effective intervention for battery thermal runaway, possessing good engineering practicality and easy integration into existing battery safety management platforms. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating the lithium battery thermal runaway safety response strategy of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0028] Reference Figure 1 A control and safety response strategy system for lithium battery thermal runaway includes a multi-sensor monitoring module, a thermal-electric coupling modeling module, a thermal runaway risk assessment module, a safety response control module, and a safety execution module. The multi-sensor monitoring module is used to collect data such as temperature, voltage, current, and gas concentration during battery operation in real time. The thermo-electric coupling modeling module constructs a thermo-electric coupling model of the lithium battery based on the collected data, which can simultaneously simulate the battery's voltage changes and heat generation, and output real-time temperature estimates and short-term temperature predictions. The thermal runaway risk assessment module identifies preset abnormal operating conditions of the battery based on the predicted values ​​output by the model and the rate of change of the monitored data. When abnormal trends are detected in parameters such as temperature or voltage, the corresponding thermal runaway risk level is determined. The safety response control module pre-sets multi-level safety response strategies, with different control logics corresponding to different risk levels. Upon receiving a risk level signal from the risk assessment module, it selects and triggers the corresponding level of safety response measures. The safety execution module includes specific execution devices, such as a cooling unit, a ventilation and gas handling unit, a power-off unit, and a fire extinguishing unit, used to perform operations such as cooling, venting, power-off, and fire extinguishing on the battery according to the instructions of the control module. Through the coordinated work of the above modules, this invention can take effective control and protection measures at each stage of lithium battery thermal runaway, significantly improving the safety of the battery system.

[0029] The multi-sensor monitoring module includes temperature sensors located on and inside the battery, voltage sensors connected to the positive and negative terminals, gas sensors monitoring the battery compartment environment, and current sensors, used to acquire comprehensive battery status information. The temperature sensors can be thermocouples or thermistors, and the gas sensors detect changes in the concentration of characteristic gases such as HF and CO released in the early stages of battery thermal runaway. The signals from each sensor are connected to a high-speed data acquisition circuit to achieve real-time monitoring of battery status parameters.

[0030] The thermo-electric coupling modeling module employs a simplified thermo-electric coupling model: the electrical part simulates the battery's voltage dynamic response using an equivalent circuit model (second-order RC network), including components such as ohmic internal resistance, polarization resistance, and double-layer capacitance; the thermal part simulates the battery's thermal behavior using a lumped-parameter thermal model, introducing battery thermal capacity and thermal resistance parameters to characterize the heat accumulation and dissipation process. By incorporating temperature feedback correction for internal resistance and calculating the heat-generated power by multiplying the square of the current by the internal resistance, bidirectional coupling between the electrical and thermal models is achieved. This model can run in real-time on the controller, providing timely temperature predictions.

[0031] The thermal runaway risk assessment module has multiple warning thresholds and judgment rules. For example, a first temperature threshold T1 is set for initial warning of thermal runaway, and a second temperature threshold T2 is set for emergency danger judgment (T2>T1); the temperature rise rate threshold ΔT / Δt is used to judge the abnormal steepness of the temperature rise; and the voltage drop threshold ΔV is used to judge whether there are signs of rapid discharge or internal short circuit. When the battery temperature exceeds T1 and the temperature rise rate is significantly greater than the normal value, it is judged to enter the warning state; when the temperature continues to rise to approach or exceed T2, or a sharp voltage drop or a sudden increase in the concentration of harmful gases is detected, it is judged to be an emergency danger state. By integrating multiple parameter signals such as temperature, voltage, and gas, this module can more reliably distinguish between mild overheating and severe runaway.

[0032] The safety response control module incorporates a model predictive control algorithm. Based on a thermo-electric coupling model, the module continuously predicts the battery's temperature change trend over the next few seconds. If the predicted temperature will exceed the safety threshold within a short period, the control module can proactively enter a higher-level response state without waiting for the actual temperature to reach the threshold. For example, if the current temperature has not yet reached T1 but the model predicts it will exceed T1 in one minute, the system triggers an early warning level response; if the predicted temperature rise rate continues to increase and may exceed T2 within tens of seconds, the system directly upgrades to emergency response mode for protection. This feedforward control approach further overcomes the lag inherent in traditional passive threshold control.

[0033] The cooling system employs a graded and controllable cooling system with two main operating modes: a normal cooling mode and an enhanced cooling mode. In normal cooling mode, the battery's temperature is managed daily through forced convection by fans or circulation of coolant via liquid cooling plates. When the battery temperature exceeds the warning threshold T1, the control module drives the fan to increase its speed or accelerates coolant circulation to increase heat dissipation. The enhanced cooling mode is used to handle emergency runaway situations, triggered when the battery temperature exceeds the danger threshold T2 or the temperature rise rate is too high. In enhanced mode, the cooling unit activates special cooling measures, such as liquid nitrogen spraying or releasing pre-placed phase change cooling material to coat the battery surface, rapidly reducing the battery temperature in a short time. The two modes can automatically switch based on temperature feedback, ensuring efficient heat dissipation under normal conditions while providing rapid, extreme cooling capabilities in critical situations.

[0034] The gas suppression device includes an exhaust duct at the top of the battery compartment and a gas treatment module connected to it. Normally, the exhaust duct is closed to maintain the battery compartment's airtightness. When the battery experiences thermal runaway and generates a large amount of gas, the control module drives an electric valve to open the exhaust duct, and a built-in small fan quickly introduces the gas from the battery compartment into the gas treatment module. The gas treatment module uses a combination of activated carbon filter and catalyst: the activated carbon layer adsorbs toxic gases such as hydrogen fluoride (HF) and carbon monoxide (CO), and the subsequent catalyst layer (e.g., honeycomb ceramic loaded with titanium dioxide) catalytically oxidizes the remaining CO to CO2 under heating conditions, and decomposes and neutralizes the unadsorbed HF. The treated gas is then discharged to the external environment through a safe exhaust duct. This gas suppression path design significantly reduces the concentration of toxic and flammable gases in the laboratory or battery compartment during battery thermal runaway, avoiding secondary hazards.

[0035] The power-off device employs a high-speed electrical disconnect switch or fuse structure, connected between the battery and the external circuit. When the system determines that it has entered an emergency protection level, the control module issues a power-off command, driving a high-voltage DC relay to disconnect the battery circuit within 100 milliseconds, quickly stopping continuous current input and output. Compared to the passive blowing of traditional fuses, this active power-off unit operates quickly and is reusable, ensuring that energy transfer is cut off in the early stages of thermal runaway, preventing a chain reaction of heat and current between the faulty battery and adjacent cells.

[0036] The fire extinguishing system employs an automatic aerosol fire suppression system. A pre-filled aerosol extinguishing agent is stored within the system and remains in standby mode. When the battery compartment temperature reaches its limit (e.g., 180°C) or the flame sensor detects an open flame, the control module immediately triggers the aerosol fire extinguishing system. The extinguishing agent is sprayed from multiple nozzles around the battery components, releasing a large number of suspended fine solid particles that quickly fill the battery compartment space. These aerosol particles chemically terminate the chain reaction of combustion, extinguishing the flames within seconds. Simultaneously, the extinguishing agent possesses electrical insulation properties, preventing secondary damage to the batteries and circuitry. After fire suppression, the gas handling module continues to operate to remove any smoke and residual gases generated after the fire.

[0037] This embodiment illustrates the specific response process of the system of the present invention under a lithium battery thermal runaway scenario. In an experiment, a 3000mAh lithium-ion battery was placed inside the protection device of this system, and the battery temperature was gradually increased by an external heating plate to simulate the thermal runaway triggering process. The control flow of the system is as follows: First, in the initial stage (normal state), the control processing unit continuously monitors parameters such as battery temperature and voltage, and finds that they are all within the normal range (e.g., battery temperature 25°C, stable rate of increase <1°C / min). The system remains on standby, only performing data recording and real-time monitoring. At this time, the cooling fan runs at low speed to maintain the battery at room temperature, and the gas handling channel is closed.

[0038] As heating progresses, the battery temperature gradually increases. When the battery casing temperature reaches a warning threshold (e.g., 60°C) and the rate of temperature rise increases significantly, the control unit determines that it has entered a Level 1 warning state. The system immediately performs the following actions: it emits a buzzer and flashing warning light through an audible and visual alarm to alert the operator; simultaneously, it switches the cooling device to enhanced air cooling mode, increasing the fan speed to improve heat dissipation and thus slow down the rate of battery temperature rise. At this time, the battery is still operating normally and its output power is not limited, but the system has entered a warning state and strengthened heat dissipation measures.

[0039] If temperature control measures fail to prevent further temperature increases, for example, due to a continuous increase in battery self-heating caused by an internal micro-short circuit, the battery temperature quickly exceeds the second-level threshold (e.g., 80°C), and the rate of temperature rise is detected to accelerate further. At this point, the control unit upgrades the risk level to a second-level intervention state and issues corresponding instructions: on the one hand, it limits the battery's charging and discharging current to less than half of its original rated value via a power-off device (equivalent to reducing battery power output to decrease heat generation); on the other hand, it triggers the emergency cooling system of the cooling device to prepare for activation—for example, opening the liquid CO2 storage tank valve to prepare for injection (at this time, because the temperature has not yet reached the highest threshold, the injection head is cooled and ready); simultaneously, it opens the exhaust valve of the gas handling device and starts the fan to forcibly extract and filter the air in the battery compartment to prevent the accumulation of potentially flammable gases. After the second-level intervention measures are implemented, the experiment observed that the upward trend of the battery temperature slowed down, and no toxic gases were detected in the environment.

[0040] In extreme cases, if a violent decomposition reaction occurs inside the battery, causing the temperature to rise rapidly and reaching the trigger conditions for a Level 3 emergency (e.g., battery temperature exceeds 100°C, and a ruptured battery safety valve is detected, resulting in a large amount of smoke), the system will immediately switch to the highest level of safety response: the control unit instantly disconnects all electrical connections between the battery and the outside world (by disconnecting the circuit through a power-off device), stopping any form of current activity in the battery; simultaneously, it sends an activation signal to the fire extinguishing device, and the aerosol fire extinguisher quickly activates, spraying extinguishing agent around the battery to extinguish any potential open flames; the emergency cooling system also activates simultaneously, with liquid CO2 sprayed at high speed through nozzles, rapidly vaporizing and absorbing heat on the battery surface, causing the battery temperature to drop significantly within seconds; the gas handling fan accelerates its operation, continuously drawing smoke generated during the fire extinguishing process and gases released from the battery into the filter box for purification. After the above comprehensive treatment, no open flame appeared in the experimental battery, and the spraying of the extinguishing agent and the action of the coolant stabilized the maximum surface temperature of the battery at around 120°C and began to decrease. After about 30 seconds, the battery temperature dropped below 80°C, and the danger was essentially eliminated.

[0041] Throughout the accident handling process, the control and processing unit also records and stores the data from various sensors and the system's actions at specific moments through its built-in data logging function. This data can be used to analyze the causes of thermal runaway and evaluate the system's response after the accident. Experimental results in this embodiment show that the system of this invention can take timely and targeted intervention measures at different stages of thermal runaway in lithium batteries, minimizing the impact of thermal runaway. For example, without the intervention of this system, the battery temperature might rapidly rise to over 300°C and cause violent combustion under the same conditions. However, after using this system for three-level control, the maximum battery temperature was limited to approximately 120°C without any open flame, and there was no significant smoke leakage in the surrounding environment. This fully verifies the effectiveness and safety protection capabilities of the invention.

[0042] This invention combines a thermo-electric coupling model with multi-sensor monitoring to accurately capture early signs of lithium battery thermal runaway and conduct risk assessment. Compared to traditional single-temperature threshold monitoring, this invention can more sensitively detect various danger signals such as sudden temperature rises and abnormal voltage changes, and initiate corresponding protective measures in advance, greatly shortening the lag time of thermal runaway response. This invention establishes a comprehensive multi-level safety response strategy: from initial warning (alarm prompts and enhanced heat dissipation) to mid-term intervention (power-limited operation and enhanced cooling, exhaust purification) to final emergency handling (power cut-off isolation, battery fire extinguishing), each level of measures is progressive and interconnected, automatically switching to the optimal control strategy according to the severity of the accident. This tiered prevention and control system effectively avoids premature or delayed responses, improving the targeting and effectiveness of safety measures. This invention also designs a dedicated gas suppression and cooling switching mechanism, which can simultaneously address the two major issues of heat and harmful gases during thermal runaway. By dynamically switching cooling methods, the system maintains efficient heat dissipation under normal operating conditions and rapidly cools down in critical situations to prevent the spread of thermal runaway. Gas-guided filtration promptly extracts and purifies leaked flammable and toxic gases from the battery, significantly reducing the risk of fire and poisoning. The combination of these two methods comprehensively controls the cascading hazards caused by battery thermal runaway. This invention abandons complex artificial intelligence algorithms and virtual simulation systems, instead employing simplified model prediction and threshold control strategies, ensuring both system architecture stability and reliability, as well as rapid real-time response. Without relying on massive historical data and high-performance computing, this system can achieve accurate prediction, early warning, and effective intervention for battery thermal runaway, possessing good engineering practicality and easy integration into existing battery safety management platforms.

[0043] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the term "comprising" or any other variations thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0044] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control and safety response strategy system for lithium battery thermal runaway, characterized in that: include: The system comprises a multi-sensor monitoring module, a thermo-electric coupling modeling module, a thermal runaway risk assessment module, a safety response control module, and a safety execution module. The multi-sensor monitoring module monitors the operating parameters of the lithium-ion battery, including battery temperature, voltage, current, and gas concentration within the battery compartment, and acquires the data for these parameters in real time. The thermo-electric coupling modeling module constructs a thermo-electric coupling model of the battery based on the operating parameters, simulating and predicting internal temperature changes and voltage responses, and providing real-time estimates and short-term predictions of the battery's temperature state. The thermal runaway risk assessment module identifies the thermal runaway risk based on the operating parameters and the predicted values. The system includes a preset abnormal operating condition for the battery. When the battery temperature and rate of temperature rise exceed a threshold or an abnormal voltage drop trend occurs, the system determines the thermal runaway risk level. The safety response control module is used to trigger corresponding multi-level safety response strategies based on the thermal runaway risk level, and generate control commands to execute predetermined safety response measures, including cooling, power regulation, gas handling, and circuit isolation. The safety execution module includes a cooling device, a gas suppression device, a power-off device, and a fire extinguishing device, which are used to cool the battery, divert and purify harmful gases, cut off circuits, and extinguish fires at different response levels, respectively, to suppress the further expansion of thermal runaway.

2. The lithium battery thermal runaway control and safety response strategy system as described in claim 1, characterized in that: The thermo-electric coupling modeling module uses a combination of equivalent circuit and lumped thermal model to perform joint electrical and thermal modeling of lithium batteries. The electrical model is based on the RC equivalent circuit to characterize the dynamic voltage characteristics of the battery, while the thermal model is based on the thermal capacity-thermal resistance network to characterize the internal heat generation and dissipation process of the battery. A bidirectional coupling is established between the electrical model and the thermal model so that the current change and the heat generation rate, and the temperature change and the internal resistance parameter interact with each other.

3. The lithium battery thermal runaway control and safety response strategy system as described in claim 1, characterized in that: The thermal runaway risk assessment module has multiple preset criteria, including battery temperature threshold, temperature rise rate threshold, and voltage drop magnitude threshold. When the battery temperature or temperature rise rate exceeds the safety threshold, or when the voltage change shows an abnormal trend, it is determined to enter the corresponding thermal runaway risk condition level.

4. The lithium battery thermal runaway control and safety response strategy system as described in claim 1, characterized in that: The cooling device has multiple cooling modes, including a normal cooling mode and an emergency cooling mode. When the battery temperature exceeds a first preset threshold, the normal cooling mode is activated to cool the battery. When the temperature continues to rise and exceeds a second preset threshold, it automatically switches to the emergency cooling mode to enhance the cooling intensity. The normal cooling mode dissipates heat through a fan or liquid cooling circulation, while the emergency cooling mode quickly suppresses the rise in battery temperature by spraying coolant or absorbing heat with phase change materials.

5. The lithium battery thermal runaway control and safety response strategy system as described in claim 1, characterized in that: The gas suppression device includes a battery compartment depressurization channel and a gas filtration and purification module connected to the channel. When the battery experiences thermal runaway and releases harmful gases, the channel will open under the instruction of the safety response control module, guiding the gas in the battery compartment into the filtration and purification module for treatment. The filtration and purification module contains activated carbon adsorbent and catalytic conversion medium, which adsorb toxic gases such as acidic gases HF and CO and convert them into harmless products, thereby reducing the concentration of harmful gases and the risk of combustion.

6. The lithium battery thermal runaway control and safety response strategy system as described in claim 1, characterized in that: The multi-level safety response strategy includes at least three response levels: Level 1 warning, Level 2 intervention, and Level 3 emergency protection. In Level 1 warning mode, the system issues an audible and visual alarm signal and activates the cooling device's normal cooling to control the temperature rise. In Level 2 intervention mode, the system reduces the battery's charging and discharging power output to a predetermined safe level, activates an enhanced cooling mode, and turns on the gas suppression device to extract and purify the gas inside the battery compartment. In Level 3 emergency protection mode, the system quickly disconnects the battery circuit, isolates the battery from external circuits via the power-off device, and triggers the fire extinguishing device to extinguish the fire on the battery.

7. The lithium battery thermal runaway control and safety response strategy system as described in claim 1, characterized in that: The safety response control module adopts a threshold enhancement strategy, which combines dynamic parameters such as temperature rise rate, voltage change rate and gas concentration change to comprehensively judge the signs of thermal runaway, and dynamically adjusts the trigger threshold conditions of each response level to improve the sensitivity and accuracy of early thermal runaway identification and reduce the false alarms or missed alarms that may be caused by a single fixed threshold.

8. The lithium battery thermal runaway control and safety response strategy system as described in claim 1, characterized in that: The safety response control module, combined with the model predictive control algorithm, predicts the temperature change trend of the battery in real time within a predetermined time period. When the prediction result shows that the battery temperature will exceed the safety threshold within the threshold time window, the module issues a control command in advance to execute cooling or power limiting measures, thereby intervening and controlling before thermal runaway occurs.

9. The lithium battery thermal runaway control and safety response strategy system as described in claim 1, characterized in that: The fire extinguishing device is an aerosol fire extinguishing system, which is installed inside the battery compartment and has multiple spray nozzles arranged towards the battery. When the battery temperature exceeds the dangerous temperature threshold or an open flame is detected, the safety response control module automatically triggers the aerosol fire extinguishing system to release the extinguishing agent instantaneously. The extinguishing agent forms uniform fine particles that are suspended around the battery, quickly covering the battery surface and suppressing the spread of the flame.

10. A method for controlling and responding to thermal runaway in a lithium battery, based on the system described in claim 1, characterized in that, Includes the following steps: S1 acquires multi-source monitoring data of the lithium battery during operation, including parameters such as battery voltage, current, temperature, and gas concentration in the battery compartment; S2 inputs the monitoring data into the thermo-electric coupling model for calculation, and calculates the current temperature state of the battery in real time and predicts the temperature change trend in a short period of time. S3 compares and analyzes the monitoring data and model prediction results with the preset safety threshold to determine whether the battery shows signs of thermal runaway such as abnormal temperature rise or abnormal voltage fluctuation, and determines the thermal runaway risk level accordingly. S4 invokes the corresponding safety response strategy based on the determined thermal runaway risk level and generates control commands to execute the predetermined safety response operations. S5 executes the control command and implements corresponding safety measures for the battery, including activating the cooling device for cooling, adjusting the charging and discharging power or cutting off the battery circuit, opening the gas suppression channel to discharge and purify harmful gases, and triggering the fire extinguishing device to extinguish the fire, so as to effectively control the battery thermal runaway state.

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