An online mass spectrometry analysis device and method for aerosol analysis during thermal runaway of lithium-ion batteries

Abstract

This invention discloses an online mass spectrometry analysis device and method for aerosols during the thermal runaway process of lithium-ion batteries, belonging to the field of analytical technology. The device includes a reaction chamber with a reaction cavity inside, in which the lithium-ion battery is placed; a heating jacket for heating the reaction chamber; a chemical ionization source for ionizing the gas output from the outlet pipe; and a mass spectrometer for detecting and analyzing the types and concentrations of ionized ions. A first thermometer and a second thermometer are installed inside the reaction chamber. The first thermometer monitors the temperature inside the reaction cavity, and the second thermometer monitors the temperature of the lithium-ion battery. A pressure gauge is also included to monitor the pressure inside the reaction cavity. This invention enables online, in-situ analysis of aerosols during the thermal runaway process of lithium-ion batteries, obtaining qualitative and quantitative information on a large number of components in the aerosols, solving the problem that existing spectroscopic and sensor technologies are insufficient for analyzing complex components.

Description

Technical Field

[0001] This invention relates to the field of analytical technology, specifically to an online mass spectrometry analysis device and method for aerosols during the thermal runaway process of lithium-ion batteries. Background Technology

[0002] With the increasing scarcity of non-renewable energy and growing awareness of energy conservation and environmental protection, lithium-ion batteries have received increasing attention. Lithium-ion batteries are composed of various chemical substances. When a battery is accidentally exposed to abuse conditions during use, such as thermal abuse (high temperature), electrical abuse (overcharging, over-discharging, internal short circuits), or mechanical abuse (squeezing, puncture), the battery temperature exceeds its normal operating temperature. Internal substances begin to react and release heat. When the rate of heat generation continuously exceeds the rate of heat dissipation, heat accumulates inside the battery, pushing up the temperature. This temperature rise further triggers a chain of exothermic reactions, such as SEI film decomposition and electrolyte oxidation, forming a self-catalytic positive feedback loop. This vicious cycle causes the system to rapidly exceed the critical temperature threshold, ultimately triggering an irreversible thermal runaway process, manifested as a sudden temperature rise, gas ejection, and combustion / explosion. Thermal runaway of lithium-ion batteries has become a major cause of safety hazards, a focus of public concern, and severely restricts the application of lithium-ion batteries. Research on the thermal runaway characteristics of lithium-ion batteries is of great significance for both safety design and performance optimization.

[0003] Currently, differential scanning calorimetry (DSC), adiabatic calorimetry (ADC), and accelerated calorimetry (ECC) are commonly used to study the thermal behavior of lithium-ion batteries during thermal runaway. Among these, DSC is widely used for testing raw materials such as lithium battery electrolytes due to its advantages of small sample size, high testing accuracy, and high safety. Adiabatic calorimetry, compared to DSC's microgram-level sample size, has a larger testing chamber and gram-level sample size, making it more commonly used for thermal runaway analysis of button batteries and small batteries such as 18650 cells. The former two methods (DSC and ECC) have functional limitations due to their limited results, and can only perform thermal runaway analysis on small batteries and raw materials. ECC, as a specialized instrument for safety testing of large batteries and battery modules, has a large testing chamber, multiple safety protections, and offers safer functional support and diverse applications for various battery runaway conditions. It is increasingly widely used in battery and battery module safety performance evaluation and active thermal runaway prevention research.

[0004] The key difference between lithium battery thermal runaway and ordinary fires and explosions lies in the fact that, in addition to the energy release from high heat and shock waves, the impact of pyrolysis gases on the external environment and personnel cannot be ignored. Pyrolysis gases are a crucial manifestation of lithium battery thermal runaway. Analyzing the changes in the composition of pyrolysis gases helps to further study the internal reactions of the battery during thermal runaway, and the detection results provide experimental evidence for inferring the internal chemical and electrochemical reactions of thermally runaway lithium batteries. Based on the composition and proportion of pyrolysis gas products, the explosion limits of the mixed gas products can be determined, providing theoretical support for assessing the safety of lithium battery use and storage. The pyrolysis gases generated during lithium battery thermal runaway are complex in composition, have a wide range of abundance, change rapidly, and exhibit significant differences in physicochemical properties. Currently, various pyrolysis gas analysis techniques have been developed to meet different analytical needs.

[0005] (1) Spectroscopic techniques Spectroscopic analysis performs qualitative and quantitative analysis of compounds by measuring their absorption or dispersion at different wavelengths. Common spectroscopic techniques include Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. A key advantage of spectroscopic analysis is its ability to perform in-situ, real-time, and non-destructive analysis. For example, Gregory Gachot used FTIR to characterize and identify volatile compounds released during battery aging and thermal runaway. Petra Andersson et al. also attempted to use FTIR technology to qualitatively and quantitatively detect toxic gases produced in lithium battery fires, successfully detecting the release of HF and POF3. Currently, there are related technologies and instruments in China, such as the LGA series laser gas analyzers from Juguang Technology (Hangzhou) Co., Ltd. However, when the composition of the pyrolysis gas is complex, the signals from different compounds superimpose, leading to highly complex spectra that are difficult to analyze effectively, and the detection sensitivity is limited.

[0006] (2) Semiconductor gas sensor technology Semiconductor gas sensors utilize the chemical reactions that occur on the surface of a semiconductor, altering the structure of the sensing element. These sensors include resistive and non-resistive types. In resistive sensors, the resistance of the semiconductor element changes upon contact with the analyte gas; the composition and concentration of the gas are determined by the functional relationship between the resistance and the analyte parameter. In non-resistive sensors, the change in certain non-resistive physical parameters after a physical or chemical reaction between the semiconductor element and the analyte gas enables direct or indirect gas detection. Semiconductor gas sensors can be used to detect gases released during lithium battery operation, offering advantages such as short response time and low detection concentration. They typically exhibit high sensitivity to the release of gases commonly found in lithium battery applications, such as H2, CO2, CO, and O2. Currently, several gas sensor companies have developed specialized semiconductor gas sensors. Examples of manufacturers include Figaro (TGS2612) from Japan, New Cosmos (KD-12B) from Japan, FIS (SB-500-12) from Japan, UST (Hydrogen Power) from Germany, City Tec (MOX-20) from the UK, and Applied Sensors (iAQ-core-C) from Europe, as well as domestic instruments such as the GDM series gas sensors from Hangzhou Puyu Technology Development Co., Ltd. However, semiconductor gas sensors also suffer from problems such as lower detection accuracy, complex gas cross-interference, and susceptibility to gas sensor poisoning.

[0007] (3) Mass spectrometry Mass spectrometry is currently the most commonly used gas analysis technique for lithium-ion batteries, offering high detection sensitivity, high throughput, and excellent qualitative and quantitative performance. As early as the late 20th century, Kazuma Kumai et al. began using gas chromatography / mass spectrometry to analyze the gas generation mechanism during the degradation process of commercial lithium-ion battery electrolytes. Through independently designed equipment capable of accurately measuring the volume of generated gas, they compared the gas production behavior of batteries after overcharging and over-discharging. Their research found that the compositional changes during normal cycling within the nominal voltage range were mainly caused by ester exchange, with very little gas production; however, a large amount of gas was detected in batteries after overcharging and over-discharging, and the electrolyte composition also underwent significant changes. Currently, several foreign companies have developed corresponding gas analysis equipment, such as the RGA Series residual gas analysis quadrupole mass spectrometer from Hiden in the UK and the HiCube RGA residual gas analysis quadrupole mass spectrometer from Pudong Development Bank in Germany, which can perform direct mass spectrometry analysis of gases. However, there are still few reports on residual gas analysis instruments in China. Domestic research still focuses more on gas chromatography-mass spectrometry (GC-MS) instruments. There is relatively mature R&D technology for these instruments in China, but due to the need for sample pretreatment and chromatographic analysis, it is difficult to achieve real-time, online analysis of gas components.

[0008] In summary, existing aerosol analysis techniques for lithium-ion battery thermal runaway processes have the following drawbacks: 1. Online methods, such as spectroscopic or sensor-based methods, can only analyze a small number of components, making it difficult to achieve simultaneous detection of multiple components; 2. Mass spectrometry methods capable of multi-component detection typically require complex sample pretreatment, making it difficult to perform online analysis of the thermal runaway process. Therefore, conducting in-situ, online, real-time, and high-coverage analysis of aerosols during lithium-ion battery thermal runaway processes is an important development trend in lithium-ion battery thermal runaway research, enabling a more accurate and efficient understanding of the gas release behavior during lithium-ion battery thermal runaway. Summary of the Invention

[0009] The purpose of this invention is to at least solve one of the technical problems existing in the prior art, and to provide an online mass spectrometry analysis device and method for aerosols in the thermal runaway process of lithium-ion batteries.

[0010] The technical solution of the present invention is as follows: An online mass spectrometry analysis device for aerosols during the thermal runaway process of a lithium-ion battery includes a reaction chamber with a reaction cavity inside, and the lithium-ion battery is placed in the reaction cavity. A heating jacket is used to heat the reaction chamber; The reaction chamber is equipped with gas supply pipes and gas outlet pipes. A chemical ionization source is used to ionize the gas output from the outlet pipe; A mass spectrometer is used to detect and analyze the types and concentrations of ions after ionization.

[0011] Preferably, the gas supply pipe is equipped with an air inlet valve, and the gas outlet pipe is equipped with an air outlet valve.

[0012] Preferably, the reaction chamber is equipped with a first thermometer and a second thermometer. The first thermometer is used to monitor the temperature inside the reaction chamber, and the second thermometer is used to monitor the temperature of the lithium-ion battery.

[0013] Preferably, the chemical ionization source includes a discharge needle connected to a high-voltage power supply, and the discharge needle is located at the outlet of the gas outlet pipe.

[0014] Preferably, it also includes a pressure gauge for monitoring the pressure of the reaction chamber.

[0015] This invention also discloses an online mass spectrometry analysis method for aerosols during the thermal runaway process of lithium-ion batteries using the above-mentioned analytical apparatus, comprising the following steps: S1: Place the lithium-ion battery into the reaction chamber, close the inlet valve and outlet valve, start the heating jacket, and record the temperature monitored by the first thermometer and the second thermometer in real time. By comparing the difference between the two temperatures, analyze the thermal effect of the lithium-ion battery thermal runaway process and obtain the temperature change curve of the lithium-ion battery thermal runaway process. S2: Place the lithium-ion battery into the reaction chamber, close the inlet valve and outlet valve, start the heating jacket, record the pressure change on the pressure gauge in real time, and calculate the volume of aerosol generated during the thermal runaway process of the lithium-ion battery through the ideal gas law, and obtain the relationship between the thermal runaway volume and temperature, i.e., the pressure change curve during the thermal runaway process. S3: Place the lithium-ion battery into the reaction chamber, open the inlet valve and outlet valve in sequence, start the chemical ionization source and mass spectrometer, introduce nitrogen into the reaction chamber through the inlet pipe, then start the heating jacket, the first thermometer records the temperature in the reaction chamber in real time, the chemical ionization source ionizes the gas components in the thermal runaway aerosol in real time, the mass spectrometer detects the ions generated by ionization in real time, obtains the type and content information of ions, and obtains the component change curve of the aerosol during the thermal runaway process.

[0016] Preferably, the lithium-ion battery is at least one of lithium iron phosphate battery, lithium manganese oxide battery, lithium titanate battery, lithium cobalt oxide battery, and ternary lithium battery.

[0017] The beneficial effects of this invention are: this invention can realize online and in-situ analysis of aerosols during the thermal runaway process of lithium-ion batteries, and can obtain qualitative and quantitative information of a large number of components in aerosols. It solves the problem that existing spectroscopic and sensor technologies are difficult to achieve complex component analysis, as well as the problem that existing mass spectrometry technology is difficult to achieve in-situ and online analysis. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the analytical device of the present invention; in the figure, 1-heating jacket, 2-iron wire, 3-lithium-ion battery, 4-reaction chamber, 5-inlet valve, 6-gas supply pipe, 7-first thermometer, 8-pressure gauge, 9-second thermometer, 10-outlet valve, 11-outlet pipe, 12-chemical ionization source, 13-mass spectrometer port.

[0019] Figure 2 Temperature change curves during thermal runaway of lithium iron phosphate batteries with different capacities; (a): 0% capacity; (b): 50% capacity; (c): 75% capacity; (d): 100% capacity.

[0020] Figure 3 The volume of aerosol generated by thermal runaway of a single 18650 lithium iron phosphate battery with different capacities.

[0021] Figure 4Ion chromatograms were selected for thermal runaway aerosol mass spectrometry analysis of six components in lithium iron phosphate batteries at 50% and 100% charge; (a): m / z 369; (b): m / z 411; (c): m / z 451; (d): m / z 465; (e): m / z 479; (f): m / z 507. Detailed Implementation

[0022] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0023] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0024] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0025] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0026] Reference Figure 1 The first embodiment of the present invention: An online mass spectrometry analysis device for aerosols during the thermal runaway process of a lithium-ion battery includes a reaction chamber, specifically a stainless steel reactor capable of withstanding 6 MPa, which has a reaction cavity 4 inside, and a lithium-ion battery 3 is placed in the reaction cavity 4. Heating jacket 1, fitted onto the outer wall of the reaction chamber, can control the temperature within the range of room temperature to 300°C and is used to heat the reaction chamber; The reaction chamber is equipped with a gas supply pipe 6 and a gas outlet pipe 11. Chemical ionization source 12 is used to ionize the gas output from gas outlet pipe 11; The mass spectrometer is used to detect and analyze ionized aerosols. The mass spectrometer port 13 is located at the outlet of the gas outlet pipe 11.

[0027] In some embodiments, an air inlet valve 5 is provided on the air supply pipe 6, and an air outlet valve 10 is provided on the air outlet pipe 11.

[0028] In some embodiments, a first thermometer 7 and a second thermometer 9 are provided in the reaction chamber. The first thermometer 7 is used to monitor the temperature inside the reaction chamber 4, and the second thermometer 9 is used to monitor the temperature of the lithium-ion battery 3.

[0029] In some embodiments, the chemical ionization source 12 includes a discharge needle connected to a high-voltage power supply, the discharge needle being located at the outlet of the gas outlet pipe 11.

[0030] Preferably, it also includes a pressure gauge 8 for monitoring the pressure of the reaction chamber 4.

[0031] The present invention also discloses a second embodiment: an online mass spectrometry analysis method for aerosols during the thermal runaway process of lithium-ion batteries using the above-mentioned analytical apparatus, comprising the following steps: S1: Place the lithium-ion battery 3 into the reaction chamber 4, close the inlet valve 5 and the outlet valve 10, start the heating jacket 1, and record the temperature monitored by the first thermometer 7 and the second thermometer 9 in real time. By comparing the difference between the two temperatures, analyze the thermal effect of the lithium-ion battery thermal runaway process and obtain the temperature change curve of the lithium-ion battery thermal runaway process. S2: Place the lithium-ion battery 3 into the reaction chamber 4, close the inlet valve 5 and the outlet valve 10, start the heating jacket 1, record the pressure change on the pressure gauge 8 in real time, and calculate the volume of aerosol generated during the thermal runaway process of the lithium-ion battery through the ideal gas law, and obtain the relationship between the thermal runaway volume and temperature, i.e. the pressure change curve of the thermal runaway process. S3: Place the lithium-ion battery 3 into the reaction chamber 4, open the inlet valve 5 and the outlet valve 10 in sequence, start the chemical ionization source 12 and the mass spectrometer, introduce nitrogen into the reaction chamber 4 through the inlet pipe 11, then start the heating jacket 1, the first thermometer 7 records the temperature in the reaction chamber 4 in real time, the chemical ionization source 12 ionizes the gas components in the thermal runaway aerosol in real time, the mass spectrometer detects the ions generated by ionization in real time, obtains the type and content information of ions, and obtains the component change curve of the aerosol during the thermal runaway process.

[0032] Specifically, the lithium-ion battery is a lithium iron phosphate battery.

[0033] Therefore, after the analysis of a lithium-ion battery, three results can be obtained: the temperature change curve during the thermal runaway process, the gas pressure change curve during the thermal runaway process, and the component change curve in the aerosol during the thermal runaway process.

[0034] The following tests were conducted using 18650 lithium iron phosphate batteries.

[0035] During the experiment, a 3kV voltage was applied to the discharge needle, the mass spectrometer port was 5cm away from the gas outlet, and nitrogen gas was used. The flow rate was 1 MPa, the heating rate of the heating jacket was 3 °C / min, and the heating time was 40 min.

[0036] 1. Thermal Effect Analysis of Lithium-ion Battery Thermal Runaway Process: Using Figure 1 The device involves placing a lithium-ion battery into the reaction chamber 4, closing the inlet valve 5 and the outlet valve 10, activating the heating jacket 1, and recording the temperatures monitored by the first thermometer 7 and the second thermometer 9 in real time. Figure 2 The results show the thermal effect analysis of the thermal runaway process of lithium iron phosphate batteries with different capacities. Figure 2 (a) It can be seen that at 0% charge, the temperature inside the reaction chamber and the surface temperature of the battery are basically the same; while Figure 2 In the 50%, 75%, and 100% charged batteries (b)-(d), it can be seen that before approximately 150°C, the temperature of the battery surface is lower than the temperature in the reaction chamber, indicating that the battery is in an endothermic process. When the temperature exceeds this critical value, the battery surface temperature is higher than the temperature in the reaction chamber, indicating that the battery is in an exothermic process until thermal runaway occurs. The thermal runaway temperature is approximately 170°C, and the thermal runaway temperature increases slightly with the increase of battery charge.

[0037] 2. Aerosol volume analysis during thermal runaway of lithium-ion batteries: using... Figure 1 The device involves placing a lithium-ion battery into the reaction chamber 4, closing the inlet valve 5 and the outlet valve 10, activating the heating jacket 1, and recording the pressure changes on the pressure gauge 8 in real time. Figure 3 The image shows the gas volume analysis results during the thermal runaway process of a single 18650 lithium iron phosphate battery with different capacities. From... Figure 3 As can be seen, the amount of gas generated during the thermal runaway of a lithium iron phosphate battery increases with the increase of the battery charge. The volume of gas generated during the thermal runaway of a lithium iron phosphate battery with a charge of 0% is about 1 L, while the volume of gas generated during the thermal runaway of a lithium iron phosphate battery with a charge of 100% is nearly 3 L, which is 3 times that of a 0% charge battery.

[0038] 3. Aerosol volume analysis during thermal runaway of lithium-ion batteries: using... Figure 1The device involves placing a lithium-ion battery into the reaction chamber 4, opening the inlet valve 5 and the outlet valve 10 in sequence, starting the chemical ionization source 12 and the mass spectrometer, introducing nitrogen gas into the reaction chamber 4 through the inlet pipe 11, and then starting the heating jacket. Figure 4 The figure shows the selected ion flow (SI) mass spectrometry of an aerosol during the thermal runaway process of a 50% and a 100% charged 18650 lithium iron phosphate battery. The figure displays the SI of six components in the aerosol. Based on the mass-to-charge ratio and the electrolyte and electrode compositions in the battery, the possible component is m / z 369 (C8H). 18 F6O6P2), m / z 411 (C 10 H 22 F6O7P2), m / z 451 (C 12 H 26 F6O8P2), m / z 465 (C 15 H 18 F9O4P), m / z 479 (C 14 H 30 F6O8P2), m / z 507 (C 16 H 34 F6O9P2), mainly consists of various reaction products of lithium hexafluorophosphate and carbonate at high temperatures. As shown in the figure, the content of all six components in the thermal runaway aerosol of batteries with different charge levels increases with increasing temperature, reaching a maximum after the thermal runaway explosion, and then decreasing. Furthermore, comparing the results for different charge levels reveals that the content of both components in the 100% charge thermal runaway aerosol is significantly higher than that in the 50% charge aerosol. These results indicate that the content of these six components is closely related to both temperature and charge level, and can be used to indicate the progress of thermal runaway. Compared to traditional GC-MS analysis, which requires collecting gas samples for analysis, during which large molecular aerosol components easily condense in the sample collection bag, thus only obtaining information on small molecular gas components (such as H2, CO2, CO, and short-chain aliphatic hydrocarbons), the method of this invention, through online mass spectrometry analysis, can monitor the entire battery thermal runaway process, obtaining dynamic changes in a large number of components in the sample, especially real-time acquisition of key component information, which is helpful for studying the mechanism of battery thermal runaway. Without causing conflict, those skilled in the art can freely combine and use the above-mentioned additional technical features.

[0039] The embodiments described above are merely preferred embodiments of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various other corresponding changes and modifications based on the technical solutions and concepts described above, and all such changes and modifications should fall within the protection scope of the claims of the present invention.

Claims

1. An online mass spectrometry analysis device for aerosols during the thermal runaway process of lithium-ion batteries, characterized in that, It includes a reaction chamber, which contains a reaction cavity, and the lithium-ion battery is placed in the reaction cavity; A heating jacket is used to heat the reaction chamber; The reaction chamber is equipped with gas supply pipes and gas outlet pipes. A chemical ionization source is used to ionize the gas output from the outlet pipe; A mass spectrometer is used to detect and analyze the types and concentrations of ions after ionization.

2. The online mass spectrometry analysis device for lithium-ion battery thermal runaway process according to claim 1, characterized in that, An inlet valve is installed on the gas supply pipeline, and an outlet valve is installed on the gas outlet pipeline.

3. The online mass spectrometry analysis device for lithium-ion battery thermal runaway process according to claim 1, characterized in that, The reaction chamber is equipped with a first thermometer and a second thermometer. The first thermometer is used to monitor the temperature inside the reaction chamber, and the second thermometer is used to monitor the temperature of the lithium-ion battery.

4. The online mass spectrometry analysis device for lithium-ion battery thermal runaway process according to claim 1, characterized in that, The chemical ionization source includes a discharge needle connected to a high-voltage power supply, and the discharge needle is located at the outlet of the gas outlet pipe.

5. The online mass spectrometry analysis device for lithium-ion battery thermal runaway process according to claim 1, characterized in that, It also includes a barometer for monitoring the pressure in the reaction chamber.

6. A method for online mass spectrometry analysis of aerosols during the thermal runaway process of lithium-ion batteries using the analytical apparatus described in any one of claims 1-5, characterized in that, Includes the following steps: S1: Place the lithium-ion battery into the reaction chamber, close the inlet valve and outlet valve, start the heating jacket, and record the temperature monitored by the first thermometer and the second thermometer in real time. By comparing the difference between the two temperatures, analyze the thermal effect of the lithium-ion battery thermal runaway process and obtain the temperature change curve of the lithium-ion battery thermal runaway process. S2: Place the lithium-ion battery into the reaction chamber, close the inlet valve and outlet valve, start the heating jacket, record the pressure change on the pressure gauge in real time, and calculate the volume of aerosol generated during the thermal runaway process of the lithium-ion battery through the ideal gas law, and obtain the relationship between the thermal runaway volume and temperature, i.e., the pressure change curve during the thermal runaway process. S3: Place the lithium-ion battery into the reaction chamber, open the inlet valve and outlet valve in sequence, start the chemical ionization source and mass spectrometer, introduce nitrogen into the reaction chamber through the inlet pipe, then start the heating jacket, the first thermometer records the temperature in the reaction chamber in real time, the chemical ionization source ionizes the gas components in the thermal runaway aerosol in real time, the mass spectrometer detects the ions generated by ionization in real time, obtains the type and content information of ions, and obtains the component change curve of the aerosol during the thermal runaway process.

7. The analytical method according to claim 1, characterized in that, The lithium-ion battery is at least one of lithium iron phosphate battery, lithium manganese oxide battery, lithium titanate battery, lithium cobalt oxide battery, and ternary lithium battery.

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