A battery thermal runaway early warning method and device

Abstract

The embodiment of the application provides a battery thermal runaway early warning method and device, the method comprises the following steps: monitoring the temperature and voltage of a target battery within a preset time period to obtain temperature monitoring data and voltage monitoring data; obtaining battery state parameters of the target battery according to the temperature monitoring data and the voltage monitoring data, wherein the battery state parameters comprise the current temperature, the current voltage, the temperature rise rate, the temperature rise time and the temperature rise trend of the target battery; determining the thermal runaway early warning level of the target battery according to the battery state parameters and a preset thermal runaway early warning model, wherein the thermal runaway early warning model is constructed based on a plurality of lithium ion batteries in different SOC states which are of the same model as the target battery; and performing thermal runaway early warning processing on the target battery according to the thermal runaway early warning level. Through the method, the thermal runaway is graded and warned, which is conducive to eliminating the thermal runaway safety hazard in time, greatly reducing the probability of thermal runaway, and is conducive to protecting the life safety of the public and reducing property losses.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically to a method and device for early warning of battery thermal runaway. Background Technology

[0002] In recent years, lithium-ion power batteries have been increasingly widely used in electric vehicles, energy storage, light electric vehicles, and electric ships. Along with the large-scale use of power batteries, fires caused by them have become more frequent, affecting a wide range of vehicles and a broad scope. Safety issues have become a key factor restricting the industry's development. Developing effective early warning and alarm systems for thermal runaway in new energy vehicles is therefore urgently needed.

[0003] The inducing factors of thermal runaway in lithium-ion power batteries typically include thermal abuse, mechanical abuse, and electrical abuse. Essentially, it stems from the accumulation of heat inside the battery, leading to overheating and triggering a chain reaction of thermal runaway within the battery.

[0004] GB 38031-2020, "Safety Requirements for Power Batteries for Electric Vehicles," clearly stipulates that a thermal event alarm signal should be provided 5 minutes before a thermal runaway of a single battery causes heat propagation, leading to a hazard in the passenger compartment. However, current industry measures for thermal runaway in lithium-ion power batteries often only generate an alarm signal when thermal runaway occurs, informing relevant personnel to evacuate. This fails to prevent the thermal runaway event from occurring, thus threatening public safety and property damage. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a battery thermal runaway early warning method and apparatus to overcome the problem in the prior art of lacking an accurate early warning method before thermal runaway of lithium-ion power batteries occurs.

[0006] This invention provides a battery thermal runaway early warning method, comprising:

[0007] The temperature and voltage of the target battery are monitored within a preset time period to obtain temperature monitoring data and voltage monitoring data.

[0008] The battery status parameters of the target battery are obtained based on the temperature monitoring data and voltage monitoring data. The battery status parameters include the current temperature, current voltage, temperature rise rate, temperature rise time, temperature rise trend, and voltage change rate of the target battery.

[0009] The thermal runaway warning level of the target battery is determined based on the battery state parameters and a preset thermal runaway warning model. The thermal runaway warning model is constructed based on multiple lithium-ion batteries with different SOC states that are the same as the target battery model.

[0010] The target battery is subjected to thermal runaway warning processing according to the thermal runaway warning level.

[0011] Optionally, the thermal runaway early warning model is generated through the following steps:

[0012] Obtain multiple lithium-ion batteries of the same model as the target battery but with different SOC states;

[0013] Heating multiple lithium-ion batteries yields temperature and voltage data for each lithium-ion battery.

[0014] Based on the temperature and voltage data of the lithium-ion batteries, multiple preset thermal runaway levels and corresponding preset voltage change thresholds, preset temperature thresholds, preset rate thresholds and preset time thresholds are determined.

[0015] The thermal runaway early warning model is generated based on multiple preset thermal runaway levels and corresponding preset voltage change thresholds, preset temperature thresholds, preset rate thresholds, and preset time thresholds.

[0016] Optionally, the preset thermal runaway level includes a first-level warning level, and the preset temperature threshold includes a first temperature threshold;

[0017] Correspondingly, determining the thermal runaway warning level of the target battery based on the battery state parameters and thermal runaway warning model includes:

[0018] If the current temperature of the target battery is greater than the first temperature threshold, then the thermal runaway warning level of the target battery is determined to be a Level 1 warning level.

[0019] Optionally, the preset thermal runaway level includes a secondary warning level, and the preset rate threshold includes a first rate threshold;

[0020] Correspondingly, determining the thermal runaway warning level of the target battery based on the battery state parameters and thermal runaway warning model includes:

[0021] Based on the fact that the current thermal runaway warning level of the target battery is the first warning level, the first temperature rise rate and the second temperature rise rate of the target battery within a preset time period are obtained.

[0022] If the current temperature of the target battery is greater than the first temperature threshold, the temperature rise trend is first increasing and then decreasing, the first temperature rise rate is greater than the second temperature rise rate, and both the first temperature rise rate and the second temperature rise rate are greater than the first rate threshold, then the thermal runaway warning level of the target battery is determined to be a level two warning level.

[0023] Optionally, the preset thermal runaway level includes a three-level warning level, and the preset temperature threshold includes a second temperature threshold;

[0024] Correspondingly, determining the thermal runaway warning level of the target battery based on the battery state parameters and thermal runaway warning model includes:

[0025] Based on the current thermal runaway warning level of the target battery being a level two warning level, the third and fourth temperature rise rates of the target battery within a preset time period are obtained.

[0026] If the current temperature of the target battery is greater than the first temperature threshold, the temperature rise trend is first increasing and then decreasing, the third temperature rise rate is greater than the fourth temperature rise rate, and both the third and fourth temperature rise rates are greater than the first rate threshold, then it is determined whether the current temperature of the target battery is greater than the second temperature threshold or whether the temperature rise time of the target battery is greater than the preset time threshold.

[0027] If the current temperature of the target battery is greater than the second temperature threshold or the temperature rise time of the target battery is greater than the preset time threshold, then the thermal runaway warning level of the target battery is determined to be a level three warning level.

[0028] Optionally, the preset thermal runaway level includes a three-level warning level, and the preset rate threshold includes a second rate threshold;

[0029] Correspondingly, determining the thermal runaway warning level of the target battery based on the battery state parameters and thermal runaway warning model includes:

[0030] Based on the current thermal runaway warning level of the target battery being a level three warning level, the voltage change rate and fifth temperature rise rate of the target battery within a preset time period are obtained.

[0031] If the voltage change rate is greater than the preset voltage change threshold or the fifth temperature rise rate is greater than the second rate threshold, then the thermal runaway warning level of the target battery is determined to be a level four warning level.

[0032] Optionally, the step of providing thermal runaway warning for the target battery based on the thermal runaway warning level includes one or more of the following:

[0033] When the thermal runaway warning level is Level 1, the target battery will be physically cooled according to the Level 1 warning level to limit the operating state of the target battery and issue a corresponding safety warning signal.

[0034] When the thermal runaway warning level is a level two warning level, the target battery is physically cooled according to the level two warning level, the target battery is controlled to enter standby mode, and a corresponding safety warning signal is issued.

[0035] When the thermal runaway warning level is a level three warning level, fire extinguishing is performed on the target battery according to the level three warning level, the target battery is controlled to enter a dormant mode, and a corresponding safety warning signal is issued.

[0036] When the thermal runaway warning level is level four, the target battery is controlled to enter a dormant mode according to the level four warning level, and a corresponding fire alarm signal is issued.

[0037] This invention also provides a battery thermal runaway early warning device, comprising:

[0038] The monitoring module is used to monitor the temperature and voltage of the target battery within a preset time period, and obtain temperature monitoring data and voltage monitoring data.

[0039] The first processing module is used to obtain the battery status parameters of the target battery based on the temperature monitoring data and voltage monitoring data. The battery status parameters include the current temperature, current voltage, temperature rise rate, temperature rise time, temperature rise trend, and voltage change rate of the target battery.

[0040] The second processing module is used to determine the thermal runaway warning level of the target battery based on the battery state parameters and a preset thermal runaway warning model. The thermal runaway warning model is constructed based on multiple lithium-ion batteries with different SOC states that are the same as the target battery model.

[0041] The third processing module is used to perform thermal runaway early warning processing on the target battery according to the thermal runaway early warning level.

[0042] This invention also provides an electronic device, including: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the method provided in this invention.

[0043] This invention also provides a computer-readable storage medium storing computer instructions for causing a computer to execute the method provided in this invention.

[0044] The technical solution of this invention has the following advantages:

[0045] This invention provides a battery thermal runaway early warning method and apparatus. The method involves monitoring the temperature and voltage of a target battery within a preset time period to obtain temperature and voltage monitoring data. Based on these data, battery state parameters are acquired, including the current temperature, current voltage, temperature rise rate, temperature rise time, and temperature rise trend. The thermal runaway early warning level is determined based on the battery state parameters and a preset thermal runaway early warning model, which is constructed using multiple lithium-ion batteries of the same model but with different states of charge (SOC). Thermal runaway early warning processing is then applied to the target battery according to the warning level. This method utilizes readily available real-time battery temperature and voltage data, along with a preset thermal runaway early warning model, to achieve graded early warning processing in overheat-induced thermal runaway scenarios. This graded early warning approach helps eliminate potential thermal runaway safety hazards in a timely manner, significantly reducing the probability of thermal runaway and thus protecting public safety and minimizing property damage. Attached Figure Description

[0046] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0047] Figure 1 This is a flowchart of the battery thermal runaway early warning method in an embodiment of the present invention;

[0048] Figure 2 This is a schematic diagram of the temperature-temperature rise rate-voltage change curves during the thermal runaway process triggered by heating of a 100% SOC ternary soft-pack power battery in an embodiment of the present invention.

[0049] Figure 3 This is a schematic diagram of the temperature-temperature rise rate-voltage change curves during the thermal runaway process triggered by heating of a 50% SOC ternary soft-pack power battery in an embodiment of the present invention.

[0050] Figure 4 This is a schematic diagram of the temperature-temperature rise rate-voltage change curves during the thermal runaway process triggered by heating of a 100% SOC ternary square-shell power battery in an embodiment of the present invention.

[0051] Figure 5 This is a schematic diagram of the temperature-temperature rise rate change curve of a 100% SOC ternary cylindrical power battery during the thermal runaway process triggered by heating in an embodiment of the present invention.

[0052] Figure 6 This is a schematic diagram of the battery thermal runaway early warning device in an embodiment of the present invention;

[0053] Figure 7 This is a schematic diagram of the structure of an electronic device in an embodiment of the present invention. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] The technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0056] Thermal stability has always been a crucial factor in the safety of power lithium batteries. For lithium-ion batteries, thermal runaway is the most serious safety incident, which can cause lithium-ion batteries to catch fire or even explode, directly threatening the safety of users.

[0057] The triggering factors for thermal runaway in lithium-ion power batteries typically include thermal abuse, mechanical abuse, and electrical abuse. Essentially, it stems from the accumulation of heat inside the battery, leading to overheating and triggering a chain reaction of thermal runaway. Currently, the industry has conducted relatively systematic research on alarm systems for lithium-ion power batteries after thermal runaway is triggered. The triggering conditions for alarm signals typically include temperature parameters, voltage parameters, battery pack internal pressure parameters, and the content of harmful gases. However, effective alarm signals can only ensure the safety of occupants and cannot prevent thermal runaway events from occurring, thus always posing a threat to public safety and property damage. Therefore, accurate early warning before thermal runaway in lithium-ion power batteries occurs is of great significance in avoiding thermal runaway events and ensuring the safety of life and property.

[0058] To address the above problems, embodiments of the present invention provide a battery thermal runaway early warning method, such as... Figure 1 As shown, the battery thermal runaway early warning method specifically includes the following steps:

[0059] Step S101: Monitor the temperature and voltage of the target battery within a preset time period to obtain temperature monitoring data and voltage monitoring data.

[0060] Specifically, temperature sensors and voltage detection devices can be used to collect the temperature and voltage signals of the target battery in real time over a certain period of time, and the collected data can be transmitted to a processor, which converts them into corresponding temperature and voltage values, i.e., temperature monitoring data and voltage monitoring data of the target battery within a preset time period.

[0061] Step S102: Obtain the battery status parameters of the target battery based on the temperature monitoring data and voltage monitoring data.

[0062] The battery status parameters include the target battery's current temperature, current voltage, temperature rise rate, temperature rise time, temperature rise trend, and voltage change rate.

[0063] Specifically, the temperature rise time refers to the time during which the target battery maintains a continuous temperature rise after exceeding its upper operating temperature limit. The temperature rise rate is a number greater than or equal to 0. It can be the real-time temperature rise rate of the target battery or the average temperature rise rate over a continuous period, such as 5 seconds. The specific setting can be flexibly configured according to actual needs, and this invention is not limited to this. The voltage change rate is determined based on the relationship between the current voltage and the initial voltage of the target battery. The temperature rise trend refers to the trend of temperature increase, such as an increasing, decreasing, or initially increasing rate followed by a decrease in the temperature rise rate.

[0064] Step S103: Determine the thermal runaway warning level of the target battery based on the battery state parameters and the preset thermal runaway warning model.

[0065] Among them, the thermal runaway early warning model is built based on multiple lithium-ion batteries with the same model but different SOC states as the target battery. The model is constructed by collecting relevant data of lithium-ion batteries with the same model but different SOC states as the target battery and performing machine learning.

[0066] Step S104: Perform thermal runaway warning processing on the target battery according to the thermal runaway warning level.

[0067] In this embodiment of the invention, the thermal runaway warning level is divided into four levels as an example. Different thermal runaway warning levels correspond to different thermal runaway warning handling methods. In practical applications, different levels can be set as needed, but this invention is not limited thereto.

[0068] By performing the above steps, the battery thermal runaway early warning method provided in this embodiment of the invention achieves graded early warning processing in overheat-induced thermal runaway scenarios by utilizing easily obtainable real-time battery temperature, voltage, and other characteristic data and employing a preset thermal runaway early warning model. This method of graded early warning for thermal runaway helps to promptly eliminate potential thermal runaway safety hazards, greatly reduces the probability of thermal runaway occurring, and helps protect public safety and reduce property damage.

[0069] Specifically, in one embodiment, the thermal runaway early warning model in step S103 above is generated through the following steps:

[0070] Step S201: Obtain multiple lithium-ion batteries of the same model as the target battery but with different SOC states.

[0071] Specifically, a corresponding battery simulation model can be built for the target battery under different SOC states to obtain multiple lithium-ion batteries of the same model but different SOC states as the target battery. Alternatively, multiple lithium-ion batteries of the same model but different SOC states as the target battery can be selected manually as the basis for subsequent experiments.

[0072] Step S202: Heat multiple lithium-ion batteries to obtain temperature and voltage data for multiple lithium-ion batteries.

[0073] Specifically, thermal runaway triggering experiments are conducted on the battery simulation model corresponding to the target battery, and the temperature and voltage data are obtained based on the simulation results. Alternatively, if the laboratory environment permits, multiple lithium-ion batteries can be heated to obtain the corresponding experimental data, namely the temperature and voltage data.

[0074] Step S203: Determine multiple preset thermal runaway levels and corresponding preset voltage change thresholds, preset temperature thresholds, preset rate thresholds, and preset time thresholds based on the temperature and voltage data of multiple lithium-ion batteries.

[0075] Specifically, in this embodiment of the invention, the preset thermal runaway level is divided into four levels. The preset thermal runaway level is set according to the thermal runaway risk of multiple lithium-ion batteries under different heating conditions. The corresponding preset voltage change threshold, preset temperature threshold, preset rate threshold and preset time threshold are generated based on real-time collected temperature data and voltage data. In practical applications, the preset thermal runaway level can also be set with different levels according to actual warning needs. This invention is not limited to this.

[0076] Step S204: Generate a thermal runaway early warning model based on multiple preset thermal runaway levels and corresponding preset voltage change thresholds, preset temperature thresholds, preset rate thresholds and preset time thresholds.

[0077] Specifically, by comprehensively referencing the simulation results of thermal runaway triggering experiments of lithium-ion batteries under different SOC states, a thermal runaway early warning model is obtained based on the data analysis of the simulation results, or a thermal runaway early warning model is obtained by referring to the actual experimental data of lithium-ion batteries under different SOC states and conducting data analysis. This makes the early warning results more consistent with actual working conditions and further improves the accuracy of the graded early warning results.

[0078] Specifically, in one embodiment, the preset thermal runaway level includes a first-level warning level, and the preset temperature threshold includes a first temperature threshold; correspondingly, the above-mentioned step S103 specifically includes the following steps:

[0079] Step S301: If the current temperature of the target battery is greater than the first temperature threshold, then the thermal runaway warning level of the target battery is determined to be a Level 1 warning level.

[0080] Specifically, the first temperature threshold is the upper limit of the normal operating temperature of the target battery. This can be the upper limit temperature given by the battery manufacturer, or the upper limit of the operating temperature obtained from relevant testing experiments on the target battery; however, this invention is not limited to these. It takes a certain amount of time for a battery to transition from a normal state to thermal runaway, with the initial change being a rise in battery temperature. Therefore, when the battery temperature exceeds its upper limit of operating temperature, a corresponding warning is issued to prompt relevant personnel to closely monitor the target battery or conduct timely inspections to prevent it from developing into thermal runaway.

[0081] Specifically, in one embodiment, the preset thermal runaway level includes a secondary warning level, and the preset rate threshold includes a first rate threshold; correspondingly, the above-mentioned step S103 specifically includes the following steps:

[0082] Step S302: Based on the current thermal runaway warning level of the target battery being Level 1, obtain the first temperature rise rate and the second temperature rise rate of the target battery within a preset time period.

[0083] Step S303: If the current temperature of the target battery is greater than the first temperature threshold, the temperature rise trend is first increasing and then decreasing, the first temperature rise rate is greater than the second temperature rise rate, and both the first and second temperature rise rates are greater than the first rate threshold, then the thermal runaway warning level of the target battery is determined to be a level two warning level.

[0084] Specifically, if the battery temperature has exceeded its upper limit operating temperature, and the target battery is determined to be at the Level 1 warning level, but the real-time temperature of the target battery continues to rise, then the latest thermal runaway warning level of the target battery needs to be reassessed. Specifically, if the first temperature rise rate of the target battery within a certain period is greater than the second temperature rise rate after a certain period (i.e., the temperature rise rate of the target battery has slowed down), and both the first and second temperature rise rates are greater than the first rate threshold, for example, both greater than 0℃ / s, then it indicates that the battery already has a risk of thermal runaway. The current thermal runaway warning level is determined to be Level 2, and corresponding warnings are issued based on the Level 2 warning level, prompting relevant personnel to take necessary measures to prevent it from developing into a higher risk level.

[0085] Specifically, in one embodiment, the preset thermal runaway level includes a three-level warning level, and the preset temperature threshold includes a second temperature threshold; correspondingly, the above-mentioned step S103 specifically includes the following steps:

[0086] Step S304: Based on the current thermal runaway warning level of the target battery being Level II, obtain the third and fourth temperature rise rates of the target battery within a preset time period.

[0087] Step S305: If the current temperature of the target battery is greater than the first temperature threshold, the temperature rise trend is first increasing and then decreasing, the third temperature rise rate is greater than the fourth temperature rise rate, and both the third and fourth temperature rise rates are greater than the first rate threshold, then determine whether the current temperature of the target battery is greater than the second temperature threshold or whether the temperature rise time of the target battery is greater than the preset time threshold.

[0088] Step S306: If the current temperature of the target battery is greater than the second temperature threshold or the temperature rise time of the target battery is greater than the preset time threshold, then the thermal runaway warning level of the target battery is determined to be a level three warning level.

[0089] Specifically, when the current thermal runaway warning level of the target battery is determined to be Level 2, the target battery continues to be monitored and warned. The temperature rise rate of the target battery in any time period, namely the third temperature rise rate and the fourth temperature rise rate, is obtained. If the temperature of the target battery has reached a very high temperature, namely the first temperature threshold, or the temperature has been rising for a long time, but the temperature rise trend is first increasing and then decreasing, and the third temperature rise rate in the previous time period is greater than the fourth temperature rise rate in the subsequent time period, and both the third and fourth temperature rise rates are greater than the first rate threshold, for example, both are greater than 0℃ / s, although the current parameter state has not yet exceeded the index corresponding to the critical state, if the target battery continues in the current state... The target battery will reach the critical state indicators within a certain period of time, but it is still necessary to determine whether the current temperature of the target battery exceeds the second temperature threshold, or whether the continuous temperature rise time of the target battery is greater than the preset time threshold. If the current temperature of the target battery exceeds the second temperature threshold, or the continuous temperature rise time of the target battery is greater than the preset time threshold, then the target battery will not immediately run away from control. However, the corresponding current thermal runaway warning level is set to level three to prompt relevant personnel to take measures such as cooling the target battery to prevent it from further developing into runaway, or to reserve preparation time for thermal runaway and remind them to take measures within the preparation time to minimize the loss of personnel and property.

[0090] Specifically, in one embodiment, the preset thermal runaway level includes four warning levels, and the preset rate threshold includes a second rate threshold; correspondingly, the above-mentioned step S103 specifically includes the following steps:

[0091] Step S307: Based on the current thermal runaway warning level of the target battery being Level 3, obtain the voltage change rate and fifth temperature rise rate of the target battery within a preset time period.

[0092] Step S308: If the voltage change rate is greater than the preset voltage change threshold or the fifth temperature rise rate is greater than the second rate threshold, then the thermal runaway warning level of the target battery is determined to be a level four warning level.

[0093] Specifically, when the current thermal runaway warning level of the target battery is determined to be Level 3, the target battery will continue to be monitored and warned. The voltage change rate and temperature rise rate of the target battery over a period of time will be obtained. The voltage change rate will be compared with a preset voltage change threshold or the fifth temperature rise rate will be compared with a second rate threshold. The preset voltage change threshold and the second rate threshold are indicators corresponding to the critical state of battery thermal runaway. If the current parameter state of the target battery exceeds the indicators corresponding to the critical state, it indicates that thermal runaway has occurred, and the current thermal runaway warning level of the target battery will be determined to be Level 4. That is, a Level 4 warning will be issued based on the Level 4 warning level to prompt relevant personnel to evacuate the site immediately and ensure the safety of life and property.

[0094] By providing four different levels of early warning for battery thermal runaway, staff can be assisted in developing corresponding thermal runaway response measures based on the current risk level. For example, when the risk level is high, protective measures related to ensuring life safety can be taken; when the risk level is low, external intervention measures can be taken to prevent the battery from developing into thermal runaway. This greatly reduces the probability of battery thermal runaway and is of great significance for ensuring life and property safety.

[0095] Specifically, in one embodiment, step S104 above includes one or more of the following thermal runaway early warning processing methods:

[0096] When the thermal runaway warning level is Level 1, physical cooling of the target battery is implemented according to the Level 1 warning level, limiting the target battery's operating state and issuing a corresponding safety warning signal. Specifically, the battery's operating state is strictly limited, such as by restricting vehicle speed or battery output power to limit the battery's drive mode, in order to prevent the battery from continuously overheating. At the same time, physical cooling of the target battery is implemented through battery thermal management technologies such as liquid cooling and air cooling, and a Level 1 safety warning signal is issued to the passenger compartment.

[0097] When the thermal runaway warning level is Level 2, physical cooling of the target battery is performed according to the Level 2 warning level, the target battery is controlled to enter standby mode, and a corresponding safety warning signal is issued. Specifically, by issuing a command to the target battery management system to enter standby mode, the battery enters standby mode, suspending some battery functions. At the same time, physical cooling of the target battery is performed using battery thermal management technologies such as liquid cooling and air cooling, and a Level 2 safety warning signal is issued to the passenger compartment.

[0098] When the thermal runaway warning level is Level 3, fire suppression measures will be implemented for the target battery according to the Level 3 warning level. The target battery will be controlled to enter a dormant mode, and a corresponding safety warning signal will be issued. Specifically, a dormant mode command will be issued to the target battery management system to put the battery into dormant mode and stop its operation. At the same time, a fire suppression command will be initiated for the target battery to carry out fire suppression, and a Level 3 safety warning will be issued to the passenger compartment to remind the occupants to prepare for evacuation.

[0099] When the thermal runaway warning level is Level IV, the target battery will be controlled to enter a dormant mode according to the Level IV warning level, and a corresponding fire alarm signal will be issued. By issuing a command to the target battery management system to enter dormant mode, the battery will enter dormant mode and stop working. At the same time, a fire extinguishing command will be initiated for the target battery, and manual fire extinguishing, cooling, and personnel evacuation operations will be carried out. A fire alarm will also be issued to the passenger compartment to remind the occupants to escape immediately.

[0100] The thermal runaway warning handling methods corresponding to the above-mentioned thermal runaway warning levels are only illustrative examples. In practical applications, the specific thermal runaway warning handling methods can be adjusted according to the management requirements of the battery and vehicle. This invention is not limited thereto.

[0101] The battery thermal runaway early warning method provided in this invention will be described in detail below with specific application examples.

[0102] In this application example, the battery thermal runaway warning system can be implemented for cells, modules, battery packs, and battery systems. The levels of battery thermal runaway warnings are classified as follows:

[0103] If the battery temperature rises and exceeds the safe temperature threshold 1, the thermal runaway warning level is determined to be Level 1.

[0104] If the battery temperature rises and exceeds the safe temperature threshold 1, and the battery temperature rise rate 1 remains greater than 0℃ / s and gradually increases, and when a certain time point is reached, the battery temperature rise rate 2 is less than the temperature rise rate 1, and the temperature rise rate 2 is greater than or equal to 0℃ / s, the thermal runaway warning level is determined to be a level 2 warning level.

[0105] If the battery temperature rises and exceeds the safe temperature threshold 1, and the battery continues to rise at a rate of 1, and at a certain point in time, the battery temperature rise rate 2 is less than the temperature rise rate 1, and the temperature rise rate 1 is greater than 0℃ / s, while the temperature rise rate 2 is greater than or equal to 0℃ / s, then when the battery temperature exceeds the temperature threshold 2, or the temperature rise time exceeds the time threshold 1, the thermal runaway warning level is determined to be a Level 3 warning level.

[0106] If the battery voltage change exceeds 1 or the temperature rise rate exceeds 3, the thermal runaway warning level is determined to be Level IV.

[0107] The data sources for battery temperature, temperature rise rate, voltage change value, and temperature rise time include: safety temperature threshold 1, temperature threshold 2, temperature rise rate 1, temperature rise rate 2, temperature rise rate 3, time threshold 1, and voltage change value 2. Safety temperature threshold 1 is the upper operating temperature limit defined by the battery manufacturer. Temperature threshold 2 and time threshold 1 are provided by step 02. Temperature rise rate 1, temperature rise rate 2, temperature rise rate 3, and voltage change value 1 are provided by the data acquisition module and the data processing module. The battery temperature, temperature rise rate, and voltage change value, as well as temperature rise rate 1 and temperature rise rate 2, are relative values, all selected as the average of temperature rise rates over a continuous period of 5-15 seconds. Temperature rise rate 3 should be greater than temperature rise rate 2, greater than or equal to 2℃ / s, and sustained for more than 3 seconds. Voltage change value 1 is 5%-10% of the initial battery voltage. The initial voltage is the battery voltage before the Level 1 warning response.

[0108] The following is an example of the construction process of the database parameter model for specific temperature thresholds, temperature rise rates, and time thresholds corresponding to different SOCs of batteries in this invention.

[0109] The method used to trigger thermal runaway is external heating. The research subjects include pouch cells, prismatic cells, and cylindrical cells, with the heating location being the central region of the large surface area of ​​the cell. (Appendix) Figure 3 , 4 Figures 5 and 6 show the temperature-temperature rise rate-voltage change curves during the thermal runaway process triggered by heating of a 100% SOC ternary soft-pack power battery, a 50% SOC ternary soft-pack power battery, a 100% SOC ternary prismatic power battery, and a 100% SOC ternary cylindrical power battery, respectively.

[0110] Before the test, the battery needs to undergo three charge-discharge cycles. According to the battery charge-discharge requirements, the battery is charged using a constant current-constant voltage charging method with a charging rate of 1C and a constant voltage charging cutoff current of 0.05C; the battery is then discharged using a constant current method with a discharge current of 1C.

[0111] The data collected during the test included battery voltage and dynamic temperature of a large area of ​​the battery casing.

[0112] Take a certain 25Ah Li(Ni) 0.8 Co 0.1 Mn 0. 1O0.1)O2-SiO x Taking the / graphite pouch power battery as an example, a thermal runaway test was conducted to trigger it.

[0113] (1) After three charge-discharge cycles, adjust the battery to 100% SOC and 50% SOC respectively.

[0114] (2) Referring to the thermal runaway triggering method in GB 38031-2020, a heating power of 300W was used to heat 25Ah Li(Ni) 0.8 Co 0.1 Mn 0. 1O0.1)O2-SiO x A thermal runaway trigger test was conducted on the / graphite pouch battery. Heating was stopped when thermal runaway was triggered. During the test, video was captured and battery voltage and temperature were recorded. The data acquisition device sampled at a frequency of 100Hz. The test ended when the thermal runaway combustion and smoke stopped, and the battery surface temperature dropped to 60°C.

[0115] (3) After the test, save the test data and clean up the site and samples.

[0116] (4) Data Analysis: See attached Figure 2 The data shown is from a 100% SOC soft-pack power battery test. It can be seen that from 42 seconds onwards, the battery begins to heat up, and the temperature of the battery casing near the heating element starts to rise, with the temperature rise rate 1 continuously increasing. During this period, the battery casing temperature exceeds the safety threshold temperature specified by the battery manufacturer. As the temperature rise rate 1 further increases, it exceeds 5℃ / s between 90 and 110 seconds. After 110 seconds, the battery temperature rise rate drops below 3.5℃ / s, at which point it is denoted as "temperature rise rate 2". At 167 seconds, the battery temperature threshold 2 reaches 300.8℃, and the temperature rise rate 3 reaches 5.2℃ / s, greater than temperature rise rate 2, and remains at this rate for more than 3 seconds. At 171 seconds, the voltage drops by more than 5% of the initial battery voltage, and thermal runaway begins.

[0117] As attached Figure 3The data shown is from a 50% SOC pouch power battery test. It can be seen that from the 39th second, the battery began to heat up, and the temperature of the battery casing near the heating element started to rise, with the temperature rise rate 1 continuously increasing. During this period, the battery casing temperature rapidly exceeded the safety threshold temperature specified by the battery manufacturer, and the temperature rise rate 1 quickly rose to over 4℃ / s, reaching its maximum value at the 51st second. From the 90th to the 110th second, the temperature rise rate 1 exceeded 5℃ / s. After the 103rd second, the battery temperature rise rate dropped below 3℃ / s, at which point it was denoted as "temperature rise rate 2". At the 188th second, the battery temperature threshold 2 reached 356.7℃, and the temperature rise rate 3 reached 4℃ / s, greater than the temperature rise rate 2, and remained there for more than 3 seconds. At the 198th second, the voltage dropped by more than 5% of the initial battery voltage, and thermal runaway began.

[0118] Based on the above test data of pouch power batteries, a database parameter model was established for pouch power batteries at 100% SOC and 50% SOC.

[0119] With a certain 75Ah Li (Ni 0.5 Co 0.2 Mn 0.3 O 0.1 Taking the O2-graphite prismatic power battery as an example, a thermal runaway test was conducted to trigger it.

[0120] (1) After three charge-discharge cycles, adjust the battery to 100% SOC.

[0121] (2) Referring to the thermal runaway triggering method in GB 38031-2020, based on the principle of slow heating, a heating power of 300W was used to heat 75Ah Li(Ni) 0.5 Co 0.2 Mn 0.3 O 0.1 The O2-graphite prismatic power battery underwent a thermal runaway trigger test. Heating was stopped when thermal runaway was triggered. During the test, video was captured and battery voltage and temperature were recorded. The data acquisition device's sampling frequency was 100Hz. The test ended when the thermal runaway combustion and smoke stopped, and the battery surface temperature dropped to 60℃.

[0122] (3) After the test, save the test data and clean up the site and samples.

[0123] (4) Data Analysis: See attached Figure 4The data shown is from a 100% SOC (State of Charge) prismatic power battery test. It can be seen that starting from 147 seconds, the battery began to heat up, and the temperature of the battery casing near the heating element began to rise, with a rapid temperature rise rate 1, reaching a maximum of 3.6℃ / s at 162 seconds. Subsequently, the battery casing temperature exceeded the safety threshold temperature specified by the battery manufacturer. Afterward, the battery temperature rise rate 2 dropped below 1℃ / s. At 2175 seconds, the battery temperature threshold 2 reached 200.2℃. At 2400 seconds, the voltage plummeted to 0V. At 2461 seconds, the temperature rise rate 3 exceeded 10℃ / s, greater than the temperature rise rate 2, and remained there for more than 3 seconds, indicating the onset of battery thermal runaway.

[0124] Based on the above test data of pouch power batteries, a database parameter model corresponding to prismatic power batteries at 100% SOC is established.

[0125] Taking a ternary cylindrical power battery with 100% SOC as an example, a thermal runaway test was conducted to trigger it.

[0126] (1) After three charge-discharge cycles, adjust the battery to 100% SOC.

[0127] (2) A thermal runaway triggering test was conducted in accordance with the thermal runaway triggering method of GB 38031-2020. Heating was stopped when the battery thermal runaway was triggered. During the test, video was captured and the battery voltage and temperature were recorded. The sampling frequency of the data acquisition device was 100Hz. The test ended when the thermal runaway combustion and smoke stopped and the battery surface temperature dropped to 60℃.

[0128] (3) After the test, save the test data and clean up the site and samples.

[0129] (4) Data Analysis: See attached Figure 5 The data shown is from a 100% SOC cylindrical power battery test. It can be seen that starting from the 55th second, the battery begins to heat up, and the battery casing temperature begins to rise. The temperature rise rate 1 increases rapidly, reaching a maximum of 2℃ / 5s at the 140th second. Subsequently, the battery casing temperature exceeds the safety threshold temperature specified by the battery manufacturer. Afterward, the battery temperature rise rate 2 drops below 1.7℃ / 5s. At the 360th second, the battery temperature threshold 2 reaches 120℃. At the 469th second, the temperature rise rate 3 exceeds 10℃ / s, greater than the temperature rise rate 2, and remains above 10℃ / s for more than 3 seconds, at which point thermal runaway begins.

[0130] Based on the above test data of soft-pack power batteries, a database parameter model corresponding to ternary cylindrical power batteries at 100% SOC is established.

[0131] By comparing the thermal runaway triggering tests of the above-listed pouch, prismatic, and cylindrical ternary lithium-ion batteries, the temperature and voltage change patterns of each test are consistent. This demonstrates the accuracy and effectiveness of the battery thermal runaway early warning method provided in this embodiment of the invention.

[0132] By performing the above steps, the battery thermal runaway early warning method provided in this embodiment of the invention achieves graded early warning processing in overheat-induced thermal runaway scenarios by utilizing easily obtainable real-time battery temperature, voltage, and other characteristic data and employing a preset thermal runaway early warning model. Using this method for graded thermal runaway early warning helps to promptly eliminate potential thermal runaway safety hazards, greatly reduces the probability of thermal runaway occurring, and helps protect public safety and reduce property damage.

[0133] This invention also provides a battery thermal runaway early warning device, such as... Figure 6 As shown, the battery thermal runaway early warning device includes:

[0134] The monitoring module 101 is used to monitor the temperature and voltage of the target battery within a preset time period, and obtain temperature monitoring data and voltage monitoring data. For details, please refer to the relevant description of step S101 in the above method embodiment, which will not be repeated here.

[0135] The first processing module 102 is used to obtain the battery state parameters of the target battery based on temperature monitoring data and voltage monitoring data. The battery state parameters include the current temperature, current voltage, temperature rise rate, temperature rise time, temperature rise trend, and voltage change rate of the target battery. For details, please refer to the relevant description of step S102 in the above method embodiment, which will not be repeated here.

[0136] The second processing module 103 is used to determine the thermal runaway warning level of the target battery based on the battery state parameters and a preset thermal runaway warning model. The thermal runaway warning model is constructed based on multiple lithium-ion batteries of the same model but different SOC states as the target battery. For details, please refer to the relevant description of step S103 in the above method embodiment, which will not be repeated here.

[0137] The third processing module 104 is used to perform thermal runaway warning processing on the target battery according to the thermal runaway warning level. For details, please refer to the relevant description of step S104 in the above method embodiment, which will not be repeated here.

[0138] Through the collaborative operation of the aforementioned components, the battery thermal runaway early warning device provided in this embodiment of the invention utilizes readily available real-time battery temperature, voltage, and other characteristic data, along with a pre-defined thermal runaway early warning model, to achieve graded early warning processing in overheating-induced thermal runaway scenarios. This method of graded early warning for thermal runaway facilitates the timely elimination of potential safety hazards, significantly reduces the probability of thermal runaway occurrence, and helps protect public safety and minimize property damage.

[0139] Further functional descriptions of the above modules are the same as those of the corresponding method embodiments described above, and will not be repeated here.

[0140] An electronic device is also provided according to embodiments of the present invention, such as Figure 7 As shown, the electronic device may include a processor 901 and a memory 902, wherein the processor 901 and the memory 902 may be connected via a bus or other means. Figure 7 Taking the example of a connection between China and Israel via a bus.

[0141] Processor 901 can be a Central Processing Unit (CPU). Processor 901 can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or combinations of the above types of chips.

[0142] The memory 902, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the methods in the method embodiments of the present invention. The processor 901 executes various functional applications and data processing of the processor by running the non-transitory software programs, instructions, and modules stored in the memory 902, thereby implementing the methods in the above method embodiments.

[0143] The memory 902 may include a program storage area and a data storage area. The program storage area may store application programs required for operating the device and at least one function; the data storage area may store data created by the processor 901, etc. Furthermore, the memory 902 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 902 may optionally include memory remotely located relative to the processor 901, and these remote memories may be connected to the processor 901 via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0144] One or more modules are stored in memory 902, and when executed by processor 901, they perform the methods described in the above method embodiments.

[0145] The specific details of the aforementioned electronic device can be understood by referring to the relevant descriptions and effects in the above method embodiments, and will not be repeated here.

[0146] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk drive (HDD), or solid-state drive (SSD), etc.; the storage medium can also include combinations of the above types of memory.

[0147] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for early warning of battery thermal runaway, characterized in that, include: The temperature and voltage of the target battery are monitored within a preset time period to obtain temperature monitoring data and voltage monitoring data. The battery status parameters of the target battery are obtained based on the temperature monitoring data and voltage monitoring data. The battery status parameters include the current temperature, current voltage, temperature rise rate, temperature rise time, temperature rise trend, and voltage change rate of the target battery. The thermal runaway warning level of the target battery is determined based on the battery state parameters and a preset thermal runaway warning model. The thermal runaway warning model is constructed based on multiple lithium-ion batteries with different SOC states that are the same as the target battery model. The target battery is subjected to thermal runaway early warning processing according to the thermal runaway early warning level; The preset thermal runaway levels are divided into four warning levels: Level 1, Level 2, Level 3, and Level 4. The preset thermal runaway levels are set based on the thermal runaway risks of multiple lithium-ion batteries under different heating conditions. The thermal runaway risks corresponding to Level 1, Level 2, Level 3, and Level 4 increase sequentially. The method of providing thermal runaway warning for the target battery based on the thermal runaway warning level includes one or more of the following: When the thermal runaway warning level is Level 1, the target battery will be physically cooled according to the Level 1 warning level to limit the operating state of the target battery and issue a corresponding safety warning signal. When the thermal runaway warning level is a level two warning level, the target battery is physically cooled according to the level two warning level, the target battery is controlled to enter standby mode, and a corresponding safety warning signal is issued. When the thermal runaway warning level is a level three warning level, fire extinguishing is performed on the target battery according to the level three warning level, the target battery is controlled to enter a dormant mode, and a corresponding safety warning signal is issued. When the thermal runaway warning level is level four, the target battery is controlled to enter a dormant mode according to the level four warning level, and a corresponding fire alarm signal is issued. The thermal runaway early warning model is generated through the following steps: Obtain multiple lithium-ion batteries of the same model as the target battery but with different SOC states; Heating multiple lithium-ion batteries yields temperature and voltage data for each lithium-ion battery. Based on the temperature and voltage data of the lithium-ion batteries, multiple preset thermal runaway levels and corresponding preset voltage change thresholds, preset temperature thresholds, preset rate thresholds and preset time thresholds are determined. The thermal runaway early warning model is generated based on multiple preset thermal runaway levels and corresponding preset voltage change thresholds, preset temperature thresholds, preset rate thresholds, and preset time thresholds. The first-level warning level is determined based on the current temperature of the target battery and a first temperature threshold. The secondary warning level is determined based on the first temperature rise rate and the second temperature rise rate of the target battery within a preset time period, on the basis that the current thermal runaway warning level of the target battery is the primary warning level. The third-level warning level is determined based on the third and fourth temperature rise rates of the target battery within a preset time period, on the basis that the current thermal runaway warning level of the target battery is the second-level warning level. The fourth-level warning level is determined based on the target battery's current thermal runaway warning level of level three, and on the voltage change rate and fifth temperature rise rate of the target battery within a preset time period.

2. The method according to claim 1, characterized in that, The Level 1 warning level is determined based on the current temperature of the target battery and a first temperature threshold, including: If the current temperature of the target battery is greater than the first temperature threshold, then the thermal runaway warning level of the target battery is determined to be a Level 1 warning level.

3. The method according to claim 2, characterized in that, The secondary warning level is determined based on the target battery's current thermal runaway warning level being the primary warning level, and is based on the target battery's first and second temperature rise rates within a preset time period, including: Based on the fact that the current thermal runaway warning level of the target battery is the first warning level, the first temperature rise rate and the second temperature rise rate of the target battery within a preset time period are obtained. If the current temperature of the target battery is greater than the first temperature threshold, the temperature rise trend is first increasing and then decreasing, the first temperature rise rate is greater than the second temperature rise rate, and both the first temperature rise rate and the second temperature rise rate are greater than the first rate threshold, then the thermal runaway warning level of the target battery is determined to be a level two warning level.

4. The method according to claim 3, characterized in that, The Level 3 warning level is determined based on the target battery's current thermal runaway warning level of Level 2, and is based on the target battery's third and fourth temperature rise rates within a preset time period, including: Based on the fact that the current thermal runaway warning level of the target battery is level two, the third temperature rise rate and the fourth temperature rise rate of the target battery within a preset time period are obtained. If the current temperature of the target battery is greater than the first temperature threshold, the temperature rise trend is first increasing and then decreasing, the third temperature rise rate is greater than the fourth temperature rise rate, and both the third and fourth temperature rise rates are greater than the first rate threshold, then it is determined whether the current temperature of the target battery is greater than the second temperature threshold or whether the temperature rise time of the target battery is greater than the preset time threshold. If the current temperature of the target battery is greater than the second temperature threshold or the temperature rise time of the target battery is greater than the preset time threshold, then the thermal runaway warning level of the target battery is determined to be a level three warning level.

5. The method according to claim 4, characterized in that, The fourth-level warning level is determined based on the target battery's current thermal runaway warning level of level three, and is based on the target battery's voltage change rate and fifth temperature rise rate within a preset time period, including: Based on the fact that the current thermal runaway warning level of the target battery is level three, the voltage change rate and the fifth temperature rise rate of the target battery within a preset time period are obtained. If the voltage change rate is greater than the preset voltage change threshold or the fifth temperature rise rate is greater than the second rate threshold, then the thermal runaway warning level of the target battery is determined to be a level four warning level.

6. A battery thermal runaway early warning device, applied to the battery thermal runaway early warning method as described in any one of claims 1-5, characterized in that, include: The monitoring module is used to monitor the temperature and voltage of the target battery within a preset time period, and obtain temperature monitoring data and voltage monitoring data. The first processing module is used to obtain the battery status parameters of the target battery based on the temperature monitoring data and voltage monitoring data. The battery status parameters include the current temperature, current voltage, temperature rise rate, temperature rise time, temperature rise trend, and voltage change rate of the target battery. The second processing module is used to determine the thermal runaway warning level of the target battery based on the battery state parameters and a preset thermal runaway warning model. The thermal runaway warning model is constructed based on multiple lithium-ion batteries with different SOC states that are the same as the target battery model. The third processing module is used to perform thermal runaway early warning processing on the target battery according to the thermal runaway early warning level.

7. An electronic device, characterized in that, include: A memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, the processor executing the computer instructions to perform the method of any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the method according to any one of claims 1 to 5.

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