Thermal runaway warning method and system based on battery gas detection

Abstract

The present invention discloses a thermal runaway warning method and system based on battery gas detection, and relates to the field of battery safety technology. The present invention aims to improve the accuracy of thermal runaway warning for lithium-ion batteries, avoid false alarms and missed alarms, and ensure accurate warnings. A reasonable threshold is set for the baseline readings, the retained baseline readings are scored and weighted, the concept of loss value is introduced, and an expected threshold range is set as a judgment standard to finely calibrate the baselines of internal and external gas sensors. Finally, the output signal is calibrated with a more accurate standard coefficient obtained based on the output signal of the internal and external gas sensors after the fine calibration of the baseline, so as to ensure that the gas sensor is substantially and effectively calibrated comprehensively, and the goal of accurate warning is achieved. The overall process ensures that the warning system is efficient and accurate, and accurately identifies the thermal runaway state of the lithium-ion battery.

Description

Technical Field

[0001] The present invention relates to the field of battery safety technology, and in particular to a thermal runaway early warning method and system based on battery gas detection. Background Art

[0002] With the global pursuit of clean energy and the rapid development of the electric vehicle market, lithium-ion batteries are increasingly used as high-performance energy storage devices. However, the safety issues of lithium-ion batteries, especially thermal runaway, have become one of the key factors limiting their widespread application. Thermal runaway refers to the self-accelerating exothermic reaction of batteries under overheating conditions. Once it occurs, it may cause the temperature of the battery to rise rapidly, causing the decomposition of internal battery materials, generating a large amount of heat and gas, and then causing fires or even explosions, resulting in serious property losses and casualties.

[0003] At present, the thermal runaway warning technology of lithium-ion batteries mainly relies on the gas detection of lithium-ion batteries through gas sensors. However, this method has certain limitations:

[0004] First, when calibrating the baseline of the gas sensor, the existing method lacks an effective mechanism to exclude low-quality or interfered baseline readings, which increases the uncertainty of the calibration results; second, the existing method does not fully consider the importance of baseline readings, which will affect the accuracy of the early warning system's judgment of thermal runaway conditions; third, due to the accuracy of baseline calibration, the existing method's early warning system is not sensitive enough to the signs of thermal runaway, making it difficult to issue early warnings in a timely manner; fourth, the existing method lacks a verification mechanism for baseline calibration, resulting in poor early warning accuracy; fifth, due to the poor accuracy of baseline calibration, the existing method is prone to deviations when calibrating the output signal of the gas sensor later, thereby failing to ensure that the gas sensor is effectively and comprehensively calibrated, which in turn easily affects the efficiency and accuracy of the entire early warning system;

[0005] Therefore, the prior art urgently needs a technical solution for a thermal runaway warning method and system based on battery gas detection. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a thermal runaway early warning method based on battery gas detection, which specifically includes the following steps:

[0007] Step S1, deploying at least two gas sensors inside and outside the lithium-ion battery;

[0008] Step S2, calibrating the gas sensor and collecting the output signal of the calibrated gas sensor, wherein the output signal is the concentration of the specific gas;

[0009] Step S2a, calibrating the gas sensors deployed inside and outside the lithium-ion battery respectively to obtain a finally calibrated gas sensor;

[0010] Step S2a1, placing the lithium-ion battery in a controlled environment;

[0011] Step S2a2, introducing a zero-point gas into the control environment, using the zero-point gas to obtain a determined optimal baseline reading, and performing a baseline calibration on the gas sensor according to the determined optimal baseline reading;

[0012] Step S2a2.1, preparing multiple sets of zero-point gases;

[0013] Step S2a2.2, introducing each group of zero-point gases into the control environment of the gas sensor in turn;

[0014] Step S2a2.3, recording the stable output signal of the gas sensor in each set of zero-point gas control environment and using it as the baseline reading;

[0015] Step S2a2.4, setting a threshold based on the baseline reading of each group of zero-point gas output, when the baseline reading is greater than or equal to the threshold, it is retained; when the baseline reading is less than the threshold, it is eliminated;

[0016] Step S2a2.5, analyzing each baseline reading of each group of zero-point gas outputs retained to obtain a determined optimal baseline reading;

[0017] Step S2a2.51, analyzing each baseline reading of each group of zero-point gas output retained according to an empirical method, and scoring each baseline reading according to the analysis result;

[0018] Step S2a2.52, assigning an initial weight to each baseline reading according to the score of each baseline reading;

[0019] Step S2a2.53, obtaining a comprehensive weight of each baseline reading according to the score of each baseline reading and the initial weight of each baseline reading;

[0020] Step S2a2.54, obtaining a predetermined optimal baseline reading according to each baseline reading and the comprehensive weight of each baseline reading;

[0021] The calculation formula for obtaining the predetermined optimal baseline reading is:

[0022]

[0023] Among them, x 预 represents the predetermined optimal baseline reading; n represents the total number of comprehensive weights of baseline readings; w i represents the comprehensive weight of the ith baseline reading; xi represents the ith baseline reading;

[0024] Step S2a2.55, setting an expected baseline reading, and obtaining a loss value of a predetermined optimal baseline reading through the expected baseline reading and the predetermined optimal baseline reading respectively;

[0025] The calculation formula for obtaining the loss value of the predetermined optimal baseline reading is:

[0026]

[0027] in, represents the loss value of the predetermined optimal baseline reading; x 预 represents the predetermined optimal baseline reading; x 期 represents the expected baseline reading;

[0028] Step S2a2.56, setting an expected threshold interval based on the loss value of the predetermined optimal baseline reading, when the loss value of the predetermined optimal baseline reading is within the expected threshold interval, determining the current predetermined optimal baseline reading as the determined optimal baseline reading; when the loss value of the predetermined optimal baseline reading is not within the expected threshold interval, returning to step S2a2.1, and re-outputting a set of predetermined optimal baseline readings until the determined optimal baseline reading is obtained;

[0029] Step S2a2.6, performing baseline calibration on the gas sensor according to the determined optimal baseline reading;

[0030] Step S2a3, introducing standard gases of known different concentrations into the gas sensor after baseline calibration as target gases to be detected by the gas sensor, obtaining each output signal of the gas sensor under the standard gases of different concentrations, and establishing a standard curve based on each output signal;

[0031] Step S2a4, based on the established standard curve, obtaining the standard coefficient of the gas sensor, and adjusting each output signal of the gas sensor based on the standard coefficient to obtain a finally calibrated gas sensor;

[0032] Step S2b, obtaining an output signal according to the gas sensor detection after the final calibration;

[0033] Step S3, converting the output signal into a digital signal, setting a normal threshold interval according to the digital signal, and judging whether the concentration of the specific gas exceeds the normal range based on the set normal threshold interval. When the digital signal is in the normal threshold interval, the concentration of the specific gas does not exceed the normal range and no warning is required; when the digital signal is not in the normal threshold interval, the concentration of the specific gas exceeds the normal range and the warning is activated;

[0034] Step S4: Generate an early warning signal according to the judgment result of the normal threshold interval, and notify relevant personnel by the early warning signal.

[0035] A thermal runaway warning system based on battery gas detection uses a thermal runaway warning method based on battery gas detection as described in any of the above items, and includes the following modules:

[0036] A sensor deployment module: used to deploy at least two gas sensors inside and outside the lithium-ion battery;

[0037] Sensor calibration and signal output module: connected to the sensor deployment module, used to calibrate the gas sensor and collect the output signal of the calibrated gas sensor, the output signal being the concentration of a specific gas;

[0038] Signal conversion and discrimination module: connected to the sensor calibration and signal output module, used to convert the output signal into a digital signal, set a normal threshold interval according to the digital signal, and judge whether the concentration of a specific gas exceeds the normal range based on the set normal threshold interval. When the digital signal is in the normal threshold interval, the concentration of the specific gas does not exceed the normal range and no warning is required; when the digital signal is not in the normal threshold interval, the concentration of the specific gas exceeds the normal range and a warning is initiated;

[0039] Early warning module: connected to the signal conversion and discrimination module, used to generate an early warning signal according to the judgment result of the normal threshold range, and notify relevant personnel by the early warning signal.

[0040] The embodiments of the present invention have the following technical effects:

[0041] The present invention aims to improve the accuracy of thermal runaway warning of lithium-ion batteries, avoid the occurrence of misjudgment and missed judgment, so as to more accurately determine whether the battery is in thermal runaway or not, and then make a more accurate warning effect; by calibrating the gas sensors deployed in the internal and external surrounding environment of the lithium-ion battery respectively, the calibration process includes calibrating the baseline of the gas sensor and calibrating the output signal of the gas sensor by a standard coefficient; wherein the baseline calibration of the gas sensor includes: first, by setting a reasonable threshold for the baseline reading, low-quality or interfered baseline readings are excluded, high-quality baseline readings are retained, the quality of baseline calibration is ensured, the error source in subsequent data analysis is reduced, and the accuracy and reliability of the warning system are improved; second, by scoring and assigning weights to the retained baseline readings, that is, assigning comprehensive weights, the predetermined optimal baseline readings finally calculated are more objective and reasonable, reflecting the different readings on the calibration The importance of the results enhances the accuracy of the early warning system's judgment on the thermal runaway state of lithium-ion batteries; third, by introducing the concept of loss value, the predetermined optimal baseline reading is compared with the expected baseline reading to quantify the deviation between the calibration result and the ideal state, which helps to further optimize the calibration process and improve the response sensitivity and judgment accuracy of the early warning system; fourth, by setting the expected threshold range as the judgment standard, it ensures that the loss value of the predetermined optimal baseline reading is within an acceptable range. When the loss value exceeds the expected threshold range, the iterative optimization of the calibration process is triggered to avoid early warning distortion caused by improper calibration and enhance the accuracy of the early warning system; the output signal of the gas sensor is calibrated by the standard coefficient, including: based on the standard coefficient obtained after establishing a standard curve for each output signal of the baseline calibrated gas sensor under different concentrations of standard gas, the output signal is calibrated by the standard coefficient, thereby obtaining the final calibrated gas sensor.

[0042] In summary, the present invention aims to improve the accuracy of thermal runaway warning of lithium-ion batteries, avoid false alarms and missed alarms, and ensure accurate warnings by finely calibrating the baselines of internal and external gas sensors. Finally, the output signals are calibrated with more accurate standard coefficients obtained based on the output signals of the internal and external gas sensors whose baselines have been finely calibrated, so as to ensure that the gas sensors are substantially and effectively calibrated comprehensively, and achieve the goal of accurate warning. The overall process ensures that the warning system is efficient and accurate, and can accurately identify the thermal runaway state of lithium-ion batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 is a flow chart of a thermal runaway early warning method based on battery gas detection provided by an embodiment of the present invention;

[0045] Figure 2 It is a framework diagram of a thermal runaway warning system based on battery gas detection provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0047] Embodiment 1: Figure 1 As shown, the present invention provides a thermal runaway early warning method based on battery gas detection, comprising the following steps:

[0048] Step S1, deploying at least two gas sensors inside and outside the lithium-ion battery;

[0049] When deploying gas sensors inside lithium-ion batteries, it is important to note that:

[0050] Inside lithium-ion batteries, gas sensors should be as close as possible to the core area of ​​the battery cell so that gas release caused by thermal runaway can be detected immediately. Sensors should be installed in the center of the battery pack or in the gaps between battery modules to ensure coverage of different areas of the entire battery pack. At least one gas sensor should be deployed here, but considering the need for redundancy and all-round monitoring, multiple sensors can be deployed. For example, in a large battery pack, a sensor can be deployed at a certain distance or near each battery module.

[0051] When deploying gas sensors in the external environment of lithium-ion batteries, it is important to note that:

[0052] On the outside of lithium-ion batteries, gas sensors should be deployed on possible gas escape paths, such as near the vents or exhaust ports of the battery pack, which helps to quickly detect any gas leaking from the inside of the battery; gas sensors should also be deployed around the lithium-ion battery storage area or battery management system control room to monitor gases that may be generated due to environmental factors or improper battery management; one gas sensor should be deployed here, but the number of gas sensors should be increased in key locations, such as vents, door gaps, etc., and high-risk areas, such as battery storage racks, to ensure monitoring without blind spots;

[0053] The types of gas sensors used may include but are not limited to: carbon monoxide sensors, hydrogen sensors, methane sensors, volatile organic compound sensors, carbon dioxide sensors, temperature sensors and humidity sensors; the specific connection method is that the gas sensor should be connected to the central monitoring system by wired or wireless means to ensure real-time transmission of data, and powered by lithium-ion batteries or through the power network of the battery management system to reduce maintenance requirements; the deployed gas sensors should be integrated with the data processing unit and the early warning system to ensure that the data can be analyzed in real time, and once abnormal gas concentration is detected, the early warning process is immediately initiated; the gas sensor should be calibrated regularly to ensure its long-term accuracy and reliability.

[0054] Step S2, calibrating the gas sensor and collecting the output signal of the calibrated gas sensor, wherein the output signal is the concentration of the specific gas;

[0055] Step S2a, calibrating the gas sensors deployed inside and outside the lithium-ion battery respectively to obtain a finally calibrated gas sensor;

[0056] Step S2a1, placing the lithium-ion battery in a controlled environment;

[0057] It is worth noting that the control environment when calibrating the gas sensor inside the lithium-ion battery is different from the control environment when calibrating the gas sensor in the external environment of the lithium-ion battery, specifically:

[0058] The calibration of the gas sensor inside the lithium-ion battery needs to be carried out in a highly controlled environment to ensure the accuracy and repeatability of the calibration. This controlled environment usually has the following characteristics: 1. Temperature control: The internal gas sensor may be affected by the operating temperature of the battery, so the controlled environment should be able to maintain a stable temperature, generally close to room temperature or the temperature range of normal battery operation, such as between 20°C and 25°C; 2. Humidity control: Humidity can affect the response of certain types of gas sensors, so the controlled environment should have humidity adjustment capabilities, usually maintained at a low humidity state, such as relative humidity below 40%; 3. Airtightness: In order to prevent interference from external gases, the control The environment needs to be sealed to ensure that only the introduced gas can affect the reading of the gas sensor; 4. Gas purity: When performing baseline calibration, the zero point gas used, such as high-purity nitrogen, must be very pure to avoid any impurities interfering with the gas sensor; 5. Airflow control: The airflow in the control environment should be uniform and adjustable so that the gas can contact the gas sensor smoothly while avoiding unstable readings caused by turbulence; 6. Pressure control: If the gas sensor is sensitive to pressure, the control environment also needs to be able to maintain constant pressure conditions, which is usually close to atmospheric pressure; 7. Electromagnetic shielding: In order to prevent electromagnetic interference, the control environment may need to have appropriate shielding measures;

[0059] Calibration of external gas sensors also requires a controlled environment, but its requirements may be different from those of internal sensors because they are more likely to be exposed to the atmosphere: 1. Environmental simulation: The controlled environment should be able to simulate the actual environmental conditions where the gas sensor will be deployed, which may include different temperatures, humidity and air pressure levels; 2. When calibrating, it is necessary to take into account the background gas concentration in the surrounding air, such as the concentration of carbon dioxide, oxygen and other potential interferents, to ensure that these gases do not affect the gas sensor during the calibration process; 3. Ventilation system: The controlled environment of the external gas sensor requires an effective ventilation system to facilitate the introduction and exhaust of standard gases of different concentrations; 4. Gas introduction and exhaust: The controlled environment should be designed with dedicated gas introduction and exhaust pipelines to ensure that standard gases can be accurately introduced and discharged in time to avoid cross contamination; 5. Safety measures: Since external gas sensors may need to calibrate their response to harmful or flammable gases, the controlled environment must be equipped with appropriate safety measures, including gas leak detection and emergency ventilation systems; 6. Storage of calibration gases: There should be safe storage facilities in the controlled environment for storing various standard gases used for calibration;

[0060] Step S2a2, introducing a zero-point gas into the control environment, using the zero-point gas to obtain a determined optimal baseline reading, and performing a baseline calibration on the gas sensor according to the determined optimal baseline reading;

[0061] Step S2a2.1, preparing multiple sets of zero-point gases;

[0062] Choose high-purity nitrogen or air as the zero gas, which does not contain the target gas component to ensure that the sensor's reading reflects only the background level; prepare multiple zero gas bottles, ensuring that the purity and pressure of each gas bottle meet the calibration requirements; clearly mark each gas bottle, including gas type, purity, batch number and expiration date;

[0063] Step S2a2.2, introducing each group of zero-point gases into the control environment of the gas sensor in turn;

[0064] Ensure that the control environment has been set up as described above, including temperature, humidity, air tightness, etc.; connect the gas introduction pipeline to ensure that the interface with the control environment and the gas sensor is well sealed; open the valve of each zero gas bottle in turn, slowly introduce the gas into the control environment, and allow the gas to be fully mixed and evenly distributed;

[0065] Step S2a2.3, recording the stable output signal of the gas sensor in each set of zero-point gas control environment and using it as the baseline reading;

[0066] After introducing each set of zero-point gas, wait for a while until the gas sensor output signal stabilizes, which usually takes several minutes; use a data recorder or computer software to record the output signal of the sensor in each set of zero-point gas environment; in order to improve the reliability of the data, each set of zero-point gas can be measured multiple times to reduce accidental errors;

[0067] Step S2a2.4, setting a threshold based on the baseline reading of each group of zero-point gas output, when the baseline reading is greater than or equal to the threshold, it is retained; when the baseline reading is less than the threshold, it is eliminated;

[0068] The collected baseline readings can be preliminarily checked to remove obviously abnormal readings; a reasonable threshold can be set based on the sensor specifications and experimental data to distinguish high-quality from low-quality baseline readings; the baseline readings can be screened using the threshold, retaining those readings above or equal to the threshold and removing those readings below the threshold;

[0069] Step S2a2.5, analyzing each baseline reading of each group of zero-point gas outputs retained to obtain a determined optimal baseline reading;

[0070] Step S2a2.51, analyzing each baseline reading of each group of zero-point gas output retained according to an empirical method, and scoring each baseline reading according to the analysis result;

[0071] Review all retained baseline readings to ensure data integrity; evaluate the stability and representativeness of each reading based on previous experimental data and domain knowledge; assign a score to each baseline reading, with higher scores indicating more stable and representative readings;

[0072] Step S2a2.52, assigning an initial weight to each baseline reading according to the score of each baseline reading;

[0073] Calculate the initial weight of each baseline reading based on the score, with higher-scoring readings being given higher weights; ensure that the sum of all initial weights equals 1 to keep the calculations in good order;

[0074] Step S2a2.53, obtaining a comprehensive weight of each baseline reading according to the score of each baseline reading and the initial weight of each baseline reading;

[0075] By combining the score with the initial weight, a composite weight for each baseline reading is calculated, which reflects the quality and importance of the reading;

[0076] Step S2a2.54, obtaining a predetermined optimal baseline reading according to each baseline reading and the comprehensive weight of each baseline reading;

[0077] The calculation formula for obtaining the predetermined optimal baseline reading is:

[0078]

[0079] Among them, x 预 represents the predetermined optimal baseline reading; n represents the total number of comprehensive weights of baseline readings; w i represents the comprehensive weight of the ith baseline reading; x i represents the ith baseline reading;

[0080] Assume there are 5 zero-point gas baseline readings: x1, x2, x3, x4, x5, and the corresponding combined weights are: W1, w2, w3, w4, w5. The goal is to use these readings and their combined weights to calculate a predetermined optimal baseline reading;

[0081] Take x1=0.01, x2=0.008, x3=0.012, x4=0.011, x5=0.009;

[0082] Take W1=0.2, W2=0.15, W3=0.3, W4=0.25, W5=0.1;

[0083] Using the above formula for calculation, the predetermined optimal baseline reading is equal to 0.01045;

[0084] Step S2a2.55, setting an expected baseline reading, and obtaining a loss value of a predetermined optimal baseline reading through the expected baseline reading and the predetermined optimal baseline reading respectively;

[0085] The calculation formula for obtaining the loss value of the predetermined optimal baseline reading is:

[0086]

[0087] in, represents the loss value of the predetermined optimal baseline reading; x 预 represents the predetermined optimal baseline reading; x 期 represents the expected baseline reading;

[0088] According to the theoretical model or historical data, an ideal baseline reading value is set. Assume that the expected baseline reading is set to 0.01. Then, using the above formula, the loss value of the predetermined optimal baseline reading is 0.00045. It is worth noting that the loss value of 0.00045 represents the difference between the predetermined optimal baseline reading and the expected baseline reading. The smaller this value is, the better the calibration effect is.

[0089] Step S2a2.56, setting an expected threshold interval based on the loss value of the predetermined optimal baseline reading, when the loss value of the predetermined optimal baseline reading is within the expected threshold interval, determining the current predetermined optimal baseline reading as the determined optimal baseline reading; when the loss value of the predetermined optimal baseline reading is not within the expected threshold interval, returning to step S2a2.1, and re-outputting a set of predetermined optimal baseline readings until the determined optimal baseline reading is obtained;

[0090] According to the sensor specifications and calibration requirements, set an expected loss value threshold range. For example, suppose we set the expected threshold range to 0.0001 to 0.001, which means that we expect the maximum deviation between the predetermined optimal baseline reading and the expected baseline reading to not exceed 0.001, and the minimum deviation to not be less than 0.0001;

[0091] Use the loss value of the predetermined optimal baseline reading calculated in step S2a2.55 to compare with the expected threshold interval, and the loss value is 0.00045. If the loss value is within the expected threshold interval, the predetermined optimal baseline reading meets the calibration accuracy requirement and can be confirmed as the determined optimal baseline reading for subsequent sensor calibration; if the loss value exceeds the expected threshold interval, the predetermined optimal baseline reading does not meet the accuracy requirement and needs to be re-acquired. If the loss value of the predetermined optimal baseline reading is not within the expected threshold interval, return to step S2a2.1, re-prepare multiple sets of zero point gases, and re-perform the entire baseline reading calibration process until a determined optimal baseline reading with a loss value that meets the expected threshold interval is obtained;

[0092] Based on the above, we calculated the loss value of 0.00045, and compared it with the expected threshold interval of 0.0001 to 0.001, it can be determined that the loss value is indeed within the expected threshold interval. Therefore, we confirm that the predetermined optimal baseline reading of 0.01045 is the determined optimal baseline reading and can be used for the subsequent sensor calibration process without re-acquisition;

[0093] Step S2a2.6, performing baseline calibration on the gas sensor according to the determined optimal baseline reading;

[0094] In the previous steps, we have determined the optimal baseline reading of 0.01045 through a series of analysis and calculations. Place the gas sensor in a zero-point gas environment to ensure that the gas sensor is only exposed to zero-point gas that does not contain the target gas; adjust the zero offset of the gas sensor so that the reading of the gas sensor matches the determined optimal baseline reading;

[0095] Step S2a3, introducing standard gases of known different concentrations into the gas sensor after baseline calibration as target gases to be detected by the gas sensor, obtaining each output signal of the gas sensor under the standard gases of different concentrations, and establishing a standard curve based on each output signal;

[0096] Prepare a series of standard gases with known concentrations, the concentrations of which cover the expected detection range of the gas sensor. For example, if the expected detection range of the sensor is 0ppm to 1000ppm of carbon monoxide, standard gases with concentrations of 0ppm, 100ppm, 500ppm and 1000ppm can be prepared. Place the gas sensor with the baseline calibration in a controlled environment, introduce standard gases of different concentrations in sequence, and ensure that only one concentration of gas is present at a time. Record the stable output signal of the sensor at each standard gas concentration, and ensure that the signal is recorded after it stabilizes to obtain accurate data. Use the recorded data to draw a standard curve with the concentration of the standard gas as the horizontal axis and the output signal of the sensor as the vertical axis. This can be done by linear regression or other statistical methods to ensure the goodness of fit of the curve.

[0097] Step S2a4, based on the established standard curve, obtaining the standard coefficient of the gas sensor, and adjusting each output signal of the gas sensor based on the standard coefficient to obtain a finally calibrated gas sensor;

[0098] The standard coefficient can be calculated from the slope of the standard curve. The slope represents the proportional relationship between the gas sensor output signal and the gas concentration. For example, if the standard curve shows that the relationship between the gas sensor output signal Y and the gas concentration X is Y=mX+b, then m is the standard coefficient. The output signal of the gas sensor is adjusted using the calculated standard coefficient to obtain the adjusted output signal of the gas sensor so that it can accurately reflect the concentration of a specific gas.

[0099] Step S2b: obtaining an output signal according to the gas sensor detection after the final calibration.

[0100] Step S3, converting the output signal into a digital signal, setting a normal threshold interval according to the digital signal, and judging whether the concentration of the specific gas exceeds the normal range based on the set normal threshold interval. When the digital signal is in the normal threshold interval, the concentration of the specific gas does not exceed the normal range and no warning is required; when the digital signal is not in the normal threshold interval, the concentration of the specific gas exceeds the normal range and the warning is activated;

[0101] The analog output signal received from the gas sensor is converted into a digital signal using an analog-to-digital converter; the safe range of the concentration of a specific gas is determined based on the standard curve and standard coefficient obtained in the previous calibration process. For example, for carbon monoxide, the normal threshold interval may be set between 0ppm and 50ppm, and any concentration outside this range is considered abnormal; the digital signal is compared with the normal threshold interval. If the concentration corresponding to the digital signal falls within the normal threshold interval, the concentration of the specific gas is considered to be within the safe range and no warning needs to be triggered; if the concentration corresponding to the digital signal exceeds the normal threshold interval, this means that the concentration of the specific gas has exceeded the normal range, and the warning mechanism needs to be activated immediately so that timely action can be taken to prevent potential dangers.

[0102] Step S4: generating an early warning signal according to the judgment result of the normal threshold interval, and notifying relevant personnel by the early warning signal;

[0103] When the concentration of a specific gas is detected to exceed the normal threshold range, the system automatically generates a warning signal. The warning signal should contain sufficient information, such as gas type, concentration level, detection time and location, so that relevant personnel can quickly understand the situation; the warning signal is sent to the relevant responsible persons through predetermined communication channels, such as on-site operators, safety supervisors or remote monitoring centers, which can be achieved through email, text messages, telephone or dedicated alarm systems; after receiving the warning signal, the relevant personnel should immediately take corresponding measures according to the emergency plan, including but not limited to evacuating personnel, stopping production activities, turning on the ventilation system, starting fire-fighting equipment, etc., to ensure the safety of personnel and facilities.

[0104] Embodiment 2: Figure 2 As shown, the present invention also proposes a thermal runaway warning system based on battery gas detection, which executes the thermal runaway warning method based on battery gas detection as described above, including the following modules:

[0105] A sensor deployment module: used to deploy at least two gas sensors inside and outside the lithium-ion battery;

[0106] Sensor calibration and signal output module: connected to the sensor deployment module, used to calibrate the gas sensor and collect the output signal of the calibrated gas sensor, the output signal being the concentration of a specific gas;

[0107] Signal conversion and discrimination module: connected to the sensor calibration and signal output module, used to convert the output signal into a digital signal, set a normal threshold interval according to the digital signal, and judge whether the concentration of a specific gas exceeds the normal range based on the set normal threshold interval. When the digital signal is in the normal threshold interval, the concentration of the specific gas does not exceed the normal range and no warning is required; when the digital signal is not in the normal threshold interval, the concentration of the specific gas exceeds the normal range and a warning is initiated;

[0108] Early warning module: connected to the signal conversion and discrimination module, used to generate an early warning signal according to the judgment result of the normal threshold range, and notify relevant personnel by the early warning signal.

[0109] Embodiment three:

[0110] An electronic device, comprising:

[0111] Processor and memory;

[0112] The processor is used to execute the steps of the thermal runaway warning method based on battery gas detection as described in any one of Embodiment 1 by calling the program or instruction stored in the memory.

[0113] Embodiment 4:

[0114] A computer-readable storage medium, the computer-readable storage medium comprising computer program instructions, the computer program instructions causing a computer to execute the steps of the thermal runaway warning method based on battery gas detection as described in any one of Embodiment 1.

[0115] The computer readable storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can include, for example, but is not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0116] It should be noted that the terms used in the present invention are only for describing specific embodiments, rather than limiting the scope of the present application. As shown in the present specification, unless the context clearly indicates an exception, the words "one", "a", "a kind of" and / or "the" do not specifically refer to the singular, but may also include the plural. The terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method or device. In the absence of more restrictions, the elements defined by the sentence "include one..." do not exclude the presence of other identical elements in the process, method or device including the elements.

[0117] It should also be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. A thermal runaway early warning method based on battery gas detection, characterized in that: The following steps are involved: Step S1, deploying at least two gas sensors inside and outside the lithium-ion battery; Step S2, calibrating the gas sensor and collecting the output signal of the calibrated gas sensor, wherein the output signal is the concentration of the specific gas; Step S2a, calibrating the gas sensors deployed inside and outside the lithium-ion battery respectively to obtain a finally calibrated gas sensor; Step S2a1, placing the lithium-ion battery in a controlled environment; Step S2a2, introducing a zero-point gas into the control environment, using the zero-point gas to obtain a determined optimal baseline reading, and performing a baseline calibration on the gas sensor according to the determined optimal baseline reading; Step S2a2.1, preparing multiple sets of zero-point gases; Step S2a2.2, introducing each group of zero-point gases into the control environment of the gas sensor in turn; Step S2a2.3, recording the stable output signal of the gas sensor in each set of zero-point gas control environment and using it as the baseline reading; Step S2a2.4, setting a threshold based on the baseline reading of each group of zero-point gas output, when the baseline reading is greater than or equal to the threshold, it is retained; when the baseline reading is less than the threshold, it is eliminated; Step S2a2.5, analyzing each baseline reading of each group of zero-point gas outputs retained to obtain a determined optimal baseline reading; Step S2a2.51, analyzing each baseline reading of each group of zero-point gas output retained according to an empirical method, and scoring each baseline reading according to the analysis result; Step S2a2.52, assigning an initial weight to each baseline reading according to the score of each baseline reading; Step S2a2.53, obtaining a comprehensive weight of each baseline reading according to the score of each baseline reading and the initial weight of each baseline reading; Step S2a2.54, obtaining a predetermined optimal baseline reading according to each baseline reading and the comprehensive weight of each baseline reading; Step S2a2.55, setting an expected baseline reading, and obtaining a loss value of a predetermined optimal baseline reading through the expected baseline reading and the predetermined optimal baseline reading respectively; The calculation formula for obtaining the loss value of the predetermined optimal baseline reading is: ； in, represents the loss value of the predetermined optimal baseline reading; represents a predetermined optimal baseline reading; represents the expected baseline reading; Step S2a2.56, setting an expected threshold interval based on the loss value of the predetermined optimal baseline reading, when the loss value of the predetermined optimal baseline reading is within the expected threshold interval, determining the current predetermined optimal baseline reading as the determined optimal baseline reading; when the loss value of the predetermined optimal baseline reading is not within the expected threshold interval, returning to step S2a2.1, and re-outputting a set of predetermined optimal baseline readings until the determined optimal baseline reading is obtained; Step S2a2.6, performing baseline calibration on the gas sensor according to the determined optimal baseline reading; Step S2a3, introducing standard gases of known different concentrations into the gas sensor after baseline calibration as target gases to be detected by the gas sensor, obtaining each output signal of the gas sensor under the standard gases of different concentrations, and establishing a standard curve based on each output signal; Step S2a4, based on the established standard curve, obtaining the standard coefficient of the gas sensor, and adjusting each output signal of the gas sensor based on the standard coefficient to obtain a finally calibrated gas sensor; Step S2b, obtaining an output signal according to the gas sensor detection after the final calibration; Step S3, converting the output signal into a digital signal, setting a normal threshold interval according to the digital signal, and judging whether the concentration of the specific gas exceeds the normal range based on the set normal threshold interval. When the digital signal is in the normal threshold interval, the concentration of the specific gas does not exceed the normal range and no warning is required; when the digital signal is not in the normal threshold interval, the concentration of the specific gas exceeds the normal range and the warning is activated; Step S4: Generate an early warning signal according to the judgment result of the normal threshold interval, and notify relevant personnel by the early warning signal.

2. The thermal runaway early warning method based on battery gas detection according to claim 1 is characterized in that: The calculation formula for obtaining the predetermined optimal baseline reading is: ; in, represents the predetermined optimal baseline reading; n represents the total number of the combined weights of the baseline readings; represents the comprehensive weight of the ith baseline reading; represents the ith baseline reading.

3. A thermal runaway warning system based on battery gas detection, used to execute the thermal runaway warning method based on battery gas detection according to any one of claims 1-2, characterized in that: The system comprises: A sensor deployment module: used to deploy at least two gas sensors inside and outside the lithium-ion battery; Sensor calibration and signal output module: connected to the sensor deployment module, used to calibrate the gas sensor and collect the output signal of the calibrated gas sensor, the output signal being the concentration of a specific gas; Signal conversion and discrimination module: connected to the sensor calibration and signal output module, used to convert the output signal into a digital signal, set a normal threshold interval according to the digital signal, and judge whether the concentration of a specific gas exceeds the normal range based on the set normal threshold interval. When the digital signal is in the normal threshold interval, the concentration of the specific gas does not exceed the normal range and no warning is required; when the digital signal is not in the normal threshold interval, the concentration of the specific gas exceeds the normal range and a warning is initiated; Early warning module: connected to the signal conversion and discrimination module, used to generate an early warning signal according to the judgment result of the normal threshold range, and notify relevant personnel by the early warning signal.

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