In-situ observation method and in-situ observation platform for heat spreading of lithium ion battery electrode

Abstract

The invention provides an in-situ observation method and an in-situ observation platform for heat spreading of a lithium ion battery electrode, and the method comprises the steps: preparing an in-situ observer in advance, the in-situ observer being a visible high-temperature-resistant cavity structure; the in-situ observation sample and a preset battery electrolyte are placed in an in-situ observer, the in-situ observer is sealed, the in-situ observation sample is a positive plate and a negative plate with a preset positive plate and negative plate area ratio, and the in-situ observer with the in-situ observation sample and the preset battery electrolyte is used for simulating a battery with visualization; performing non-contact heating on the in-situ observation sample in the in-situ observer to trigger the thermal runaway process of the in-situ observation sample to obtain the in-situ observation sample after thermal runaway; and carrying out in-situ observation analysis on the in-situ observation sample after thermal runaway. The lithium ion battery electrode heat spreading in-situ observation can be performed with low cost and high efficiency.

Description

Technical Field

[0001] This invention relates to the field of battery thermal safety testing technology, and in particular to an in-situ observation method and platform for thermal propagation of lithium-ion battery electrodes. Background Technology

[0002] The growth of the electric vehicle market is largely attributed to advancements in lithium-ion battery technology. However, thermal runaway in lithium-ion batteries poses a significant obstacle to the further development of electric vehicles.

[0003] According to relevant technologies, various thermal runaway mechanisms of lithium-ion batteries have been studied. Abuse conditions that may lead to thermal runaway include mechanical abuse, electrical abuse, and thermal abuse. Internal short circuits are a common feature of all types of abuse conditions in lithium-ion batteries, and different abuse conditions can lead to various types of internal short circuits. In-situ observation of thermal runaway allows researchers to gain a deeper understanding of the complex processes and mechanisms that occur during thermal runaway, and can help determine the root cause of battery failure and develop mitigation or prevention strategies. However, current in-situ observation techniques for thermal runaway often rely on relatively expensive equipment and stringent experimental conditions, resulting in higher costs for in-situ observation of thermal runaway. Summary of the Invention

[0004] This invention provides an in-situ observation method and platform for thermal propagation of lithium-ion battery electrodes, enabling low-cost and high-efficiency in-situ observation of thermal propagation of lithium-ion battery electrodes.

[0005] This invention provides an in-situ observation method for thermal propagation of lithium-ion battery electrodes. The method includes: pre-preparing an in-situ observer, wherein the in-situ observer is a high-temperature resistant cavity structure with visibility; placing an in-situ observation sample and a preset battery electrolyte into the in-situ observer, and sealing the in-situ observer, wherein the in-situ observation sample is a positive and negative electrode sheet with a preset positive and negative electrode sheet area ratio, and the in-situ observer containing the in-situ observation sample and the preset battery electrolyte is used to simulate a visible battery; performing non-contact heating on the in-situ observation sample placed in the in-situ observer to trigger the thermal runaway process of the in-situ observation sample, obtaining a thermal runaway in-situ observation sample; and performing in-situ observation analysis on the thermal runaway in-situ observation sample.

[0006] According to the present invention, an in-situ observation method for thermal propagation of lithium-ion battery electrodes, before performing in-situ observation and analysis on the in-situ observation sample after thermal runaway, the method further includes: acquiring gas information, pressure information, and temperature information within the in-situ observer, wherein the gas information is gas information generated by the in-situ observation sample during thermal runaway; the pressure information is pressure information formed by the in-situ observation sample during thermal runaway; and the temperature information is temperature information formed by the in-situ observation sample during thermal runaway. The in-situ observation and analysis of the in-situ observation sample after thermal runaway includes: performing in-situ observation and analysis on the in-situ observation sample after thermal runaway based on the gas information, the pressure information, and the temperature information.

[0007] According to the present invention, an in-situ observation method for thermal propagation of lithium-ion battery electrodes is provided, wherein gas information within the in-situ observer is obtained by means of the following method: an in-situ gas chromatography-mass spectrometry (GC-MS) instrument is connected to the in-situ observer to obtain gas information within the in-situ observer based on the GC-MS instrument, and to measure the gas composition of the gas information in-situ based on the GC-MS instrument.

[0008] According to the present invention, an in-situ observation method for thermal propagation of lithium-ion battery electrodes is provided, wherein pressure information within the in-situ observer is obtained by means of the following: a pressure sensor is configured for the in-situ observer to obtain pressure information within the in-situ observer based on the pressure sensor, and the pressure value of the pressure information is measured in-situ based on the pressure sensor.

[0009] According to the present invention, an in-situ observation method for thermal propagation of lithium-ion battery electrodes is provided, wherein temperature information within the in-situ observer is obtained by means of the following: a temperature sensor is configured for the in-situ observer to obtain temperature information within the in-situ observer based on the temperature sensor, and the temperature value of the temperature information is measured in-situ based on the temperature sensor.

[0010] According to the present invention, an in-situ observation method for thermal propagation of lithium-ion battery electrodes is provided, wherein the in-situ observation sample is prepared by disassembling a fully charged pouch battery in a drying chamber to obtain positive and negative electrode sheets; and the positive and negative electrode sheets are matched according to a preset positive and negative electrode sheet area ratio to obtain the in-situ observation sample.

[0011] According to the present invention, an in-situ observation method for thermal spread of lithium-ion battery electrodes is provided, wherein the in-situ observation sample placed in the in-situ observer is heated without contact, comprising: heating the in-situ observation sample placed in the in-situ observer without contact based on an induction coil, or heating the in-situ observation sample placed in the in-situ observer without contact based on a laser source.

[0012] The present invention also provides an in-situ observation platform for thermal propagation of lithium-ion battery electrodes. The in-situ observation platform is used to implement the in-situ observation method for thermal propagation of lithium-ion battery electrodes as described in any one of the claims. The in-situ observation platform includes: an in-situ observer, which is a high-temperature resistant cavity structure with visibility, and a non-contact heating source. The non-contact heating source is used to non-contactly heat the in-situ observation sample placed in the in-situ observer to trigger the thermal runaway process of the in-situ observation sample, thereby obtaining the in-situ observation sample after thermal runaway.

[0013] According to the present invention, an in-situ observation platform for thermal propagation of lithium-ion battery electrodes is provided, the in-situ observation platform further comprising: an in-situ gas chromatography-mass spectrometry (GC-MS) instrument connected to the in-situ observer for acquiring gas information within the in-situ observer; a pressure sensor disposed in the in-situ observer for acquiring pressure information within the in-situ observer; and a temperature sensor disposed in the in-situ observer for acquiring temperature information within the in-situ observer, wherein the gas information is gas information generated by the in-situ observed sample during thermal runaway; the pressure information is pressure information formed by the in-situ observed sample during thermal runaway; and the temperature information is temperature information formed by the in-situ observed sample during thermal runaway.

[0014] According to the present invention, an in-situ observation platform for thermal spread of lithium-ion battery electrodes is provided, wherein the non-contact heating source includes at least one or more of induction coils and laser sources.

[0015] This invention provides an in-situ observation method and platform for thermal propagation of lithium-ion battery electrodes. The method includes: pre-fabricating an in-situ observer, wherein the in-situ observer is a high-temperature resistant cavity structure with visibility; placing an in-situ observation sample and a preset battery electrolyte into the in-situ observer, and sealing the in-situ observer, wherein the in-situ observation sample consists of positive and negative electrode sheets with a preset positive and negative electrode area ratio, and the in-situ observer containing the in-situ observation sample and the preset battery electrolyte is used to simulate a visible battery; performing non-contact heating on the in-situ observation sample placed in the in-situ observer to trigger the thermal runaway process of the in-situ observation sample, obtaining a thermal runaway in-situ observation sample; and performing in-situ observation analysis on the thermal runaway in-situ observation sample. This method enables low-cost and high-efficiency in-situ observation of thermal propagation of lithium-ion battery electrodes. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating the in-situ observation method for thermal propagation of lithium-ion battery electrodes provided by the present invention.

[0018] Figure 2 This is a schematic diagram of the process for in-situ observation and analysis of samples after thermal runaway, provided by the present invention.

[0019] Figure 3 This is a schematic diagram of the in-situ observation platform for thermal propagation of lithium-ion battery electrodes provided by the present invention.

[0020] Figure label: 300: In-situ observation platform for thermal propagation of lithium-ion battery electrodes; 310: In-situ observer; 320: Non-contact heating source; 330: In-situ gas chromatography-mass spectrometry system; 340: Temperature sensor; 350: Pressure sensor. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0022] In the accompanying drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0023] In the description of this embodiment, it should be understood that the terms "center," "longitudinal," "lateral," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this embodiment 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, and therefore should not be construed as a limitation on the scope of protection of this embodiment. It should be noted that unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components described in these embodiments do not limit the scope of the invention.

[0024] Figure 1 This is a flowchart illustrating the in-situ observation method for thermal propagation of lithium-ion battery electrodes provided by the present invention.

[0025] The following will combine Figure 1 The process of the in-situ observation method for thermal propagation of lithium-ion battery electrodes provided by the present invention will be described.

[0026] In an exemplary embodiment of the present invention, combined with Figure 1 As can be seen, the in-situ observation method for thermal propagation of lithium-ion battery electrodes can include steps 110 to 140, and each step will be described below.

[0027] In step 110, an in-situ observer is prepared in advance, wherein the in-situ observer is a high-temperature resistant cavity structure with visibility.

[0028] In one embodiment, the cavity can be fabricated using high-purity tempered glass. The cavity is used to contain the sample and electrolyte. A sealed electrode interface and a liquid injection / vacuuming channel are located at the top of the cavity. The cavity is entirely transparent, allowing for observation from multiple angles both circumferentially and axially, providing visibility.

[0029] In another embodiment, the in-situ observer can also be fabricated as follows: Two pieces of tempered glass, each 320 mm long, 130 mm wide, and 5 mm thick, are used. Multiple rubber ropes with a diameter of 3.5 mm are fixed around the perimeter of the glass, approximately 10 mm from the edge. An electrode is fixed in the center, and the outer ring is filled with a high-temperature resistant inorganic adhesive. After the adhesive dries, the rubber ropes are removed, and the remaining gaps and cracks are filled again with inorganic adhesive, thus forming a visible, high-temperature resistant cavity structure.

[0030] In step 120, the in-situ observation sample and the preset battery electrolyte are placed into the in-situ observation device, and the in-situ observation device is sealed. The in-situ observation sample is a positive and negative electrode with a preset positive and negative electrode area ratio. The in-situ observation device containing the in-situ observation sample and the preset battery electrolyte is used to simulate a battery with visualization capabilities.

[0031] In one embodiment, an in-situ observation sample and a preset battery electrolyte can be placed into an in-situ observer. The in-situ observation sample can be positive and negative electrodes with a preset positive and negative electrode area ratio. It should be noted that the preset positive and negative electrode area ratio can be adjusted according to actual conditions and is not specifically limited in this embodiment. The preset battery electrolyte can be a battery electrolyte necessary to ensure the formation of a battery; in addition, it may include flame retardants, etc. In this embodiment, the preset battery electrolyte is not specifically limited. The in-situ observer containing the in-situ observation sample and the preset battery electrolyte can be used to simulate a visualized battery.

[0032] In step 130, the in-situ observation sample placed in the in-situ observer is heated without contact to trigger the thermal runaway process of the in-situ observation sample, thereby obtaining the in-situ observation sample after thermal runaway.

[0033] In step 140, in-situ observation and analysis are performed on the in-situ observation sample after thermal runaway.

[0034] In one embodiment, the sealed in-situ observer can be placed in the center of a high-frequency induction heating coil. The coil is connected to a high-frequency power supply, and eddy current heating is applied to the in-situ observation sample inside the cavity through the principle of electromagnetic induction to achieve non-contact heating, thereby triggering the thermal runaway process of the in-situ observation sample and obtaining the in-situ observation sample after thermal runaway. In one example, the in-situ observation sample after thermal runaway can be considered as the positive and negative electrodes after thermal runaway.

[0035] In another embodiment, in-situ observation and analysis of samples after thermal runaway can be performed through the transparent walls of the cavity. During application, CT scans can be performed on the samples after thermal runaway. The CT test data format is 16-bit unsigned integers, generating 2^16 grayscale values. Brighter areas generally represent materials with higher density, but due to limitations in test accuracy and data quality, the raw data often contains noise. Therefore, Avizo 3D software can be used for data smoothing and optimization. Materials with different grayscale value ranges are extracted for 3D reconstruction and label analysis.

[0036] Furthermore, a fragment can be cut from the thermal runaway sample (corresponding to the in-situ observation sample after thermal runaway) near the thermal runaway trigger location. A higher-precision CT scan is performed on a smaller area of ​​the cut sample, and this part of the CT data is analyzed in detail to achieve in-situ observation and analysis of the in-situ observation sample after thermal runaway.

[0037] In this embodiment, the high-temperature resistant transparent cavity can simulate the closed internal environment of the battery, thereby facilitating users to conduct in-situ observation and analysis of the sample after thermal runaway. In addition, non-contact heating avoids heat loss interference, contamination or mechanical stress caused by contact with external heaters, ensuring that thermal runaway is purely caused by internal material reactions, improving the controllability and repeatability of the triggering process, and enabling low-cost and high-efficiency in-situ observation of thermal propagation of lithium-ion battery electrodes.

[0038] This invention provides an in-situ observation method for thermal propagation of lithium-ion battery electrodes. The method includes: pre-fabricating an in-situ observer, wherein the in-situ observer is a high-temperature resistant cavity structure with visibility; placing an in-situ observation sample and a preset battery electrolyte into the in-situ observer, and sealing the in-situ observer, wherein the in-situ observation sample is a positive and negative electrode sheet with a preset positive and negative electrode sheet area ratio, and the in-situ observer containing the in-situ observation sample and the preset battery electrolyte is used to simulate a visible battery; performing non-contact heating on the in-situ observation sample placed in the in-situ observer to trigger the thermal runaway process of the in-situ observation sample, obtaining a thermal runaway in-situ observation sample; and performing in-situ observation analysis on the thermal runaway in-situ observation sample. This method enables low-cost and high-efficiency in-situ observation of thermal propagation of lithium-ion battery electrodes.

[0039] Figure 2 This is a schematic diagram of the process for in-situ observation and analysis of samples after thermal runaway, provided by the present invention.

[0040] The following will combine Figure 2 The process of in-situ observation and analysis of samples after thermal runaway, provided by this invention, is described.

[0041] In an exemplary embodiment of the present invention, combined with Figure 2 As can be seen, in-situ observation and analysis of samples after thermal runaway can include steps 210 and 220, which will be described in detail below.

[0042] In step 210, gas information, pressure information, and temperature information within the in-situ observer are acquired. The gas information refers to the gas generated by the in-situ observed sample during thermal runaway; the pressure information refers to the pressure formed by the in-situ observed sample during thermal runaway; and the temperature information refers to the temperature formed by the in-situ observed sample during thermal runaway.

[0043] In step 220, based on gas information, pressure information, and temperature information, in-situ observation and analysis are performed on the in-situ observation sample after thermal runaway.

[0044] In one embodiment, the changes in characteristic parameters of gas information, pressure information, and temperature information within the in-situ observer can be monitored in real time. Furthermore, in-situ observation and analysis of the in-situ observation sample after thermal runaway can be achieved based on the changes in characteristic parameters of gas information, pressure information, and temperature information within the in-situ observer.

[0045] In an exemplary embodiment of the present invention, continuing with the previously described embodiments, obtaining gas information within the in-situ observer can be achieved in the following manner: An in-situ gas chromatography-mass spectrometry (GC-MS) instrument is connected to an in-situ observer to acquire gas information within the observer based on the GC-MS instrument. Gas composition based on in-situ measurement of gas information using in-situ gas chromatography-mass spectrometry.

[0046] In one embodiment, the gas from the in-situ observer can be connected to an in-situ gas chromatography-mass spectrometry (GC-MS) instrument, which enables real-time measurement and calibration of the gas components generated during the thermal runaway process, and analysis of the chemical reactions that occur during thermal runaway.

[0047] In an exemplary embodiment of the present invention, continuing with the previously described embodiments, obtaining pressure information within the in-situ observer can be achieved in the following manner: A pressure sensor is configured for the in-situ observer to acquire pressure information within the observer. Pressure values ​​based on in-situ pressure measurements using pressure sensors.

[0048] In one embodiment, a pressure sensor can be introduced into the in-situ observer to monitor the changes in pressure values ​​during thermal runaway in real time.

[0049] In an exemplary embodiment of the present invention, continuing with the previously described embodiments, the acquisition of temperature information within the in-situ observer can be achieved in the following manner: A temperature sensor is configured for the in-situ observer to obtain temperature information within the observer. Temperature values ​​based on in-situ temperature measurements using temperature sensors.

[0050] In one embodiment, a temperature sensor can be introduced into the in-situ observer to monitor the temperature changes during thermal runaway in real time.

[0051] In another embodiment, different ratios of fully charged negative and positive electrode plates can be set in the in-situ observer to observe and analyze the intensity of the thermal runaway reaction, and quantitatively analyze the contribution of different ratios of positive and negative electrode materials to the thermal runaway temperature, pressure, and gas composition. In yet another example, negative electrode material at different locations on the negative electrode plate can be erased and then combined with positive electrode material again. It can be observed whether the area where the negative electrode material was erased can prevent the spread of thermal runaway on the electrode plate, and the intensity of the thermal runaway reaction can be observed and analyzed, quantitatively analyzing the contribution of different ratios of positive and negative electrode materials to the thermal runaway temperature, pressure, and gas composition.

[0052] It is understandable that setting different ratios of fully charged negative and positive electrode plates, as well as erasing negative electrode material at different positions on the negative electrode plate and continuing to combine it with the positive electrode material, can all be considered as providing positive and negative electrode plates with a preset positive and negative electrode plate area ratio.

[0053] In yet another exemplary embodiment of the present invention, the in-situ observation sample can be prepared in the following manner, using the previously described embodiments as an example: The fully charged pouch cell was disassembled in a drying chamber to obtain the positive and negative electrode plates; According to the preset positive and negative electrode area ratio, the positive and negative electrode areas are matched to obtain the in-situ observation sample.

[0054] In one embodiment, a fully charged battery can be disassembled in a drying chamber, different electrode ratios can be set, and the battery can be repackaged into a thermal runaway in-situ observation sample. Setting different electrode ratios can be considered as matching the positive and negative electrode areas according to a preset positive-to-negative electrode area ratio.

[0055] In yet another exemplary embodiment of the present invention, continuing with the previously described embodiments, non-contact heating of the in-situ observation sample placed inside the in-situ observer can be achieved in the following manner: Non-contact heating of in-situ observation samples placed inside an in-situ observer based on induction coils, or The in-situ observation sample is heated non-contactly by using a laser source and placed inside the in-situ observer.

[0056] In one embodiment, the in-situ observation sample placed within the in-situ observer can be heated using a non-contact heating method. In application, high-frequency induction heating, a non-contact rapid heating method, can be employed. High-frequency heating generates a skin effect, significantly increasing the heating rate of highly conductive materials such as copper and aluminum. High-frequency electromagnetic induction heating is a non-contact, efficient, and rapid method for triggering thermal runaway. Combined with a self-made lithium-ion battery electrode-level thermal runaway in-situ observer, it enables in-situ observation of the thermal runaway and thermal propagation process of a fully charged electrode.

[0057] As described above, this invention proposes an in-situ observation method for thermal runaway of lithium-ion battery electrodes. This involves disassembling a fully charged battery in a drying chamber, setting different electrode ratios, and repackaging it into a thermal runaway in-situ observation sample. The sample is then fixed in a self-made in-situ observer. Thermal runaway and thermal propagation are triggered by heating the electrodes with an induction coil. Finally, the electrode sample after the thermal runaway experiment is analyzed using CT scanning. This method can help to better understand the complex processes and mechanisms that occur during thermal runaway and to develop corresponding strategies to mitigate or prevent thermal runaway of lithium-ion batteries.

[0058] Based on the same inventive concept, the present invention also provides an in-situ observation platform for thermal spread of lithium-ion battery electrodes. The in-situ observation platform for thermal spread of lithium-ion battery electrodes will be described below in conjunction with the following embodiments.

[0059] Figure 3 This is a schematic diagram of the in-situ observation platform for thermal propagation of lithium-ion battery electrodes provided by the present invention.

[0060] The following will combine Figure 3 The structure of the in-situ observation platform for thermal propagation of lithium-ion battery electrodes provided by the present invention will be described.

[0061] In an exemplary embodiment of the present invention, the in-situ observation platform for thermal propagation of lithium-ion battery electrodes can be used to implement the in-situ observation method for thermal propagation of lithium-ion battery electrodes described in any of the preceding claims. Combined with... Figure 3 As can be seen, the in-situ observation platform 300 for the thermal spread of lithium-ion battery electrodes may include an in-situ observer 310 and a non-contact heating source 320. Each component will be described in detail below.

[0062] The in-situ observer 310 is a high-temperature resistant cavity structure with visibility; The non-contact heating source 320 can be used to non-contactly heat the in-situ observation sample placed in the in-situ observer 310 to trigger the thermal runaway process of the in-situ observation sample and obtain the in-situ observation sample after thermal runaway.

[0063] In one embodiment, the in-situ observation sample placed within the in-situ observer 310 can be non-contactly heated using a non-contact heating source 320, thereby triggering the thermal runaway process of the in-situ observation sample and obtaining the in-situ observation sample after thermal runaway. In one example, the in-situ observation sample after thermal runaway can be considered as the positive and negative electrodes after thermal runaway.

[0064] In another embodiment, in-situ observation and analysis of samples after thermal runaway can be performed through the transparent walls of the cavity. During application, CT scans can be performed on the samples after thermal runaway. The CT test data format is 16-bit unsigned integers, generating 2^16 grayscale values. Brighter areas generally represent materials with higher density, but due to limitations in test accuracy and data quality, the raw data often contains noise. Therefore, Avizo 3D software can be used for data smoothing and optimization. Materials with different grayscale value ranges are extracted for 3D reconstruction and label analysis.

[0065] Furthermore, a fragment can be cut from the thermal runaway sample (corresponding to the in-situ observation sample after thermal runaway) near the thermal runaway trigger location. A higher-precision CT scan is performed on a smaller area of ​​the cut sample, and this part of the CT data is analyzed in detail to achieve in-situ observation and analysis of the in-situ observation sample after thermal runaway.

[0066] In yet another exemplary embodiment of the present invention, continuing with Figure 3 The above-described embodiment is used as an example for illustration. The in-situ observation platform 300 for thermal propagation of lithium-ion battery electrodes may also include an in-situ gas chromatography-mass spectrometry instrument 330, a pressure sensor 350, and a temperature sensor 340. Each component will be described in detail below.

[0067] The in-situ gas chromatography-mass spectrometry system 330 is connected to the in-situ observer 310 to acquire gas information within the in-situ observer 310.

[0068] Pressure sensor 350 is installed in in-situ observer 310 to acquire pressure information within in-situ observer 310.

[0069] Temperature sensor 340 is disposed in in-situ observer 310 to acquire temperature information within in-situ observer 310. Specifically, the gas information is the gas generated by the in-situ observed sample during thermal runaway; the pressure information is the pressure formed by the in-situ observed sample during thermal runaway; and the temperature information is the temperature formed by the in-situ observed sample during thermal runaway.

[0070] In application, temperature sensors 340 and pressure sensors 350 can be introduced into the in-situ observer 310 to monitor changes in characteristic parameters such as gas information, pressure information, and temperature information in real time during thermal runaway. The gas from the in-situ observer 310 can be connected to an in-situ gas chromatography-mass spectrometry (GC-MS) instrument to achieve real-time measurement and calibration of the gas components generated during thermal runaway, and to analyze the chemical reactions occurring during thermal runaway. Different ratios of fully charged negative and positive electrodes can be set in the in-situ observer 310 to observe and analyze the intensity of the thermal runaway reaction, and to quantitatively analyze the contribution of different ratios of positive and negative electrode materials to the thermal runaway temperature, pressure, and gas components. By erasing negative electrode material from different locations on the negative electrode and then combining it with the positive electrode material, it can be observed whether the area where the negative electrode material was erased can prevent the spread of thermal runaway on the electrode, and a scheme to guide battery thermal safety design can be proposed.

[0071] In yet another exemplary embodiment of the present invention, the description continues with the embodiments described above. The non-contact heating source may include at least one or more of the following: an induction coil and a laser source.

[0072] In one embodiment, the in-situ observation sample placed within the in-situ observer can be heated using a non-contact heating method. In application, high-frequency induction heating, a non-contact rapid heating method, can be employed. High-frequency heating can generate a skin effect, significantly increasing the heating rate of highly conductive materials such as copper and aluminum. High-frequency electromagnetic induction heating is a non-contact, efficient, and rapid method for triggering thermal runaway. Combined with a self-made lithium-ion battery electrode-level thermal runaway in-situ observer, in-situ observation of the thermal runaway and thermal propagation process of a fully charged electrode can be achieved. It is understood that although operations are described in a specific order in the accompanying drawings in the embodiments of the present invention, this should not be construed as requiring these operations to be performed in the specific order or serial order shown, or requiring all of the shown operations to obtain the desired result. In certain environments, multitasking and parallel processing may be advantageous.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An in-situ observation method for thermal propagation of lithium-ion battery electrodes, characterized in that, The method includes: An in-situ observer is prefabricated, wherein the in-situ observer is a high-temperature resistant cavity structure with visibility; An in-situ observation sample and a preset battery electrolyte are placed into the in-situ observation device, and the in-situ observation device is sealed. The in-situ observation sample is a positive and negative electrode with a preset positive and negative electrode area ratio. The in-situ observation device containing the in-situ observation sample and the preset battery electrolyte is used to simulate a battery with visualization capabilities. The in-situ observation sample placed in the in-situ observer is heated without contact to trigger the thermal runaway process of the in-situ observation sample, thereby obtaining the in-situ observation sample after thermal runaway. In-situ observation and analysis were performed on the samples observed after thermal runaway.

2. The in-situ observation method for thermal propagation of lithium-ion battery electrodes according to claim 1, characterized in that, Before performing in-situ observation and analysis on the sample after thermal runaway, the method further includes: The gas information, pressure information, and temperature information within the in-situ observer are acquired, wherein the gas information is the gas information generated by the in-situ observed sample during thermal runaway; the pressure information is the pressure information formed by the in-situ observed sample during thermal runaway; and the temperature information is the temperature information formed by the in-situ observed sample during thermal runaway. The in-situ observation and analysis of the sample after thermal runaway includes: Based on the gas information, the pressure information, and the temperature information, in-situ observation and analysis are performed on the in-situ observation sample after thermal runaway.

3. The in-situ observation method for thermal propagation of lithium-ion battery electrodes according to claim 2, characterized in that, The gas information within the in-situ observer is obtained using the following method: An in-situ gas chromatography-mass spectrometry (GC-MS) instrument is connected to an in-situ observer to acquire gas information within the in-situ observer based on the GC-MS instrument. The gas composition is determined in situ based on the gas composition measured using the in-situ gas chromatography-mass spectrometry instrument.

4. The in-situ observation method for thermal propagation of lithium-ion battery electrodes according to claim 2, characterized in that, The pressure information within the in-situ observer is obtained using the following method: A pressure sensor is configured for the in-situ observer to acquire pressure information within the in-situ observer based on the pressure sensor. The pressure value is based on the pressure sensor's in-situ measurement of the pressure information.

5. The in-situ observation method for thermal propagation of lithium-ion battery electrodes according to claim 2, characterized in that, The temperature information within the in-situ observer is obtained using the following method: A temperature sensor is configured for the in-situ observer to acquire temperature information within the observer based on the temperature sensor. The temperature value is based on the in-situ measurement of the temperature information using the temperature sensor.

6. The in-situ observation method for thermal propagation of lithium-ion battery electrodes according to claim 1 or 2, characterized in that, The in-situ observation samples were prepared using the following method: The fully charged pouch cell was disassembled in a drying chamber to obtain the positive and negative electrode plates; According to the preset positive and negative electrode area ratio, the positive and negative electrode sheets are matched in terms of area to obtain the in-situ observation sample.

7. The in-situ observation method for thermal propagation of lithium-ion battery electrodes according to claim 1 or 2, characterized in that, The non-contact heating of the in-situ observation sample placed within the in-situ observer includes: The in-situ observation sample placed inside the in-situ observer is heated without contact using an induction coil, or The in-situ observation sample placed inside the in-situ observer is heated non-contactly using a laser source.

8. An in-situ observation platform for thermal propagation of lithium-ion battery electrodes, characterized in that, The in-situ observation platform is used to implement the in-situ observation method for thermal propagation of lithium-ion battery electrodes as described in any one of claims 1 to 7, and the in-situ observation platform includes: An in-situ observer, wherein the in-situ observer is a high-temperature resistant cavity structure with visibility, and A non-contact heating source is used to non-contactly heat the in-situ observation sample placed in the in-situ observer to trigger the thermal runaway process of the in-situ observation sample and obtain the in-situ observation sample after thermal runaway.

9. The in-situ observation platform for thermal propagation of lithium-ion battery electrodes according to claim 8, characterized in that, The in-situ observation platform also includes: An in-situ gas chromatography-mass spectrometry (GC-MS) instrument is connected to the in-situ observer to acquire gas information within the in-situ observer. A pressure sensor is disposed in the in-situ observer and is used to acquire pressure information within the in-situ observer. A temperature sensor, disposed in the in-situ observer, is used to acquire temperature information within the in-situ observer. The gas information refers to the gas generated by the in-situ observed sample during thermal runaway; the pressure information refers to the pressure formed by the in-situ observed sample during thermal runaway; and the temperature information refers to the temperature formed by the in-situ observed sample during thermal runaway.

10. The in-situ observation platform for thermal propagation of lithium-ion battery electrodes according to claim 8, characterized in that, Non-contact heating sources include at least one or more of the following: induction coils and laser sources.

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