A jacket for inhibiting thermal runaway of a power battery

Abstract

The application discloses a jacket for inhibiting thermal runaway of a power battery, comprising a heat-sensitive sheet, a gas generation structure, a power battery jacket and a power battery, wherein the power battery is arranged in the interior of the power battery jacket, the gas generation structure is arranged in the jacket cavity of the power battery jacket, the jacket cavity of the power battery jacket is provided with uniformly distributed through holes on the upper wall surface, and the heat-sensitive sheet is filled in the through holes; when the power battery occurs thermal runaway, the power battery transmits heat to the heat-sensitive sheet and the gas generation structure on the power battery jacket, the heat-sensitive sheet in the through hole volatilizes, the gas generation structure generates aerosol through chemical reaction, the aerosol overflows from the through hole and covers the power battery in thermal runaway, so that the thermal runaway of the power battery is inhibited. The application can actively intervene in the initial stage of the thermal runaway of the power battery, rapidly reduce the temperature of the power battery, and is suitable for various thermal runaway scenes of the power battery, so that the thermal runaway of the power battery is actively and effectively inhibited.

Description

Technical Field

[0001] This invention relates to the field of power battery thermal runaway suppression technology, specifically to a jacket for suppressing power battery thermal runaway. Background Technology

[0002] Currently, the new energy vehicle industry has entered a new stage of large-scale development. Data shows that among common accidents involving new energy vehicles, those caused by power system failures such as thermal runaway of power batteries and electric drive failure account for a high proportion, resulting in a large number of personal and property losses and seriously restricting the green transformation and safe development of the transportation industry.

[0003] Heating, overcharging, puncture, short circuit, compression, and over-discharge can all lead to thermal runaway of power batteries and cause safety accidents. Therefore, efficient thermal runaway management of power batteries is essential.

[0004] Existing technologies for protecting power batteries from thermal runaway can be categorized into three types: passive insulation, active fire suppression, and material modification. Passive insulation, such as the patent application CN115149202A entitled "A Thermal Runaway Protection Device for a Power Battery in a New Energy Vehicle," includes a battery pack, a battery pack insulation layer, and a heat release pipe. This device can protect the battery pack and vehicle from fire and explosion in the event of thermal runaway in a single battery cell. However, the insulation material only delays heat transfer and cannot actively suppress the chain reaction of thermal runaway in the battery. It is prone to failure during severe thermal runaway, and the heat release pipe requires sufficiently high internal pressure to open, creating a time window blind spot. Active fire suppression technologies, such as vehicle-mounted aerosol extinguishing systems... Fire extinguishing agents or perfluorohexanone spray systems are used to protect power batteries from thermal runaway. However, due to the reliance on external temperature sensors for triggering, the response delay is 10-15 seconds, and the extinguishing agent has a short suspension time in the sealed battery pack, resulting in an inhibition efficiency of less than 70%. Some fluorinated extinguishing agents also pose environmental residue risks. Material modification methods, such as the patent application CN120389167A entitled "A High-Safety Battery Design Method for Suppressing Thermal Runaway and Thermal Propagation," involve coating the exposed part of the positive electrode current collector inside the battery with a certain thickness of functional material. This functional material has high resistance characteristics and can suppress the battery discharge effect caused by short circuits. However, it has no ability to suppress thermal runaway that has already occurred, and it comes at the cost of sacrificing performance under normal operating conditions. Furthermore, it is only suitable for a limited range of operating conditions and cannot cover non-short-circuit thermal runaway. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a jacket for suppressing thermal runaway of power batteries. It actively intervenes in the early stages of thermal runaway of power batteries, rapidly reducing the temperature of the power batteries. It is applicable to various thermal runaway scenarios of power batteries, thereby actively and effectively suppressing thermal runaway of power batteries.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A jacket for suppressing thermal runaway of a power battery includes: a thermistor, a gas generating structure, a power battery jacket, and a power battery. The power battery is disposed inside the power battery jacket. The gas generating structure is provided in the jacket cavity of the power battery jacket. The upper wall of the jacket cavity of the power battery jacket has evenly distributed through openings, and the thermistor is filled in the openings. When a power battery experiences thermal runaway, it transfers heat to the thermistor and gas generating structure on the battery jacket. The thermistor in the opening evaporates, and the gas generating structure decomposes to produce aerosols. The aerosols overflow from the opening and cover the thermally runaway power battery, thus suppressing the thermal runaway.

[0008] Furthermore, the heat-sensitive sheet comprises: 80% to 85% by mass of natural dextrorotatory camphor, 12% to 14% by mass of ethyl hydroxyacetate, and the remainder being lactic acid oligomers with a molecular weight of 800 to 1200.

[0009] Furthermore, the preparation process of the thermistor is as follows: i: Weigh out natural dextrorotatory camphor, ethyl glycolate and lactic acid oligomer respectively; ii: Grind natural dextrorotatory camphor and lactic acid oligomer separately, add ethyl hydroxyethyl dropwise to the ground lactic acid oligomer, and grind until uniformly mixed to obtain a mixed powder; iii: Add the ground natural dextrorotatory camphor to the mixed powder in portions, and grind until uniformly mixed to obtain a particle size of Thermosensitive powder; iv: Thermosensitive powder is filled into a cylindrical mold and pressed under a pressure of 1~3MPa for 10~30s. After demolding, the thermosensitive sheet is obtained.

[0010] Furthermore, the diameter of the thermal sheet is 1~3mm, and the diameter of the thermal sheet is 0.1mm larger than the diameter of the opening. The thermal sheet is filled into the opening by extrusion.

[0011] Furthermore, the gas generating structure comprises: 30% to 45% by mass of cerium ammonium nitrate, 5% to 15% by mass of ammonium perchlorate, 5% to 15% by mass of boron nanoparticles, 2% to 8% by mass of polyethylene glycol, 10% to 15% by mass of hydroxyapatite, and the remainder being hydrated vermiculite.

[0012] Furthermore, the preparation process of the gas generating structure is as follows: cerium ammonium nitrate, ammonium perchlorate, nano-boron powder, polyglycolic acid, hydroxyapatite, and hydrated vermiculite are mixed sequentially and ground uniformly to obtain a particle size of [missing information]. The gas generation structure.

[0013] Furthermore, the width of the jacket cavity of the power battery jacket satisfies:

[0014] in, This indicates the width of the jacket cavity of the power battery jacket. This indicates the maximum heat release during thermal runaway of the power battery. This represents an empirical coefficient, with a value range of 0.02. ~5 .

[0015] Furthermore, the power battery and the inner wall of the power battery jacket are in a gapless mechanical contact.

[0016] Furthermore, the power battery jacket uses a material with a thermal conductivity of not less than [a certain value]. Thermally conductive materials.

[0017] Compared with the prior art, the present invention has the following beneficial effects: In this invention, the thermistor in the jacket that suppresses thermal runaway of the power battery completely volatilizes in the early stage of thermal runaway. That is, this invention adopts a thermistor triggering mechanism, which can actively detect thermal runaway of the power battery without external power supply or signal input. At the same time, the gas generating structure undergoes a thermal decomposition reaction in the early stage of thermal runaway of the power battery, producing a large amount of inert gas and particulate solids, forming a high-density aerosol. The aerosol rushes out from the opening of the volatilized thermistor and covers the surface of the thermal runaway power battery, achieving rapid fire suppression.

[0018] In summary, this invention, through thermal sensing, can quickly suppress thermal runaway of the power battery as long as the temperature exceeds 120°C. It can achieve proactive prevention and control in the early stages of thermal runaway, improving the timeliness and effectiveness of thermal runaway suppression. At the same time, it can comprehensively suppress thermal runaway of the power battery under scenarios such as heating, overcharging, puncture, short circuit, compression, and over-discharge. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the jacket used in the present invention to suppress thermal runaway of a power battery. Figure 2 This is a cross-sectional view of the jacket for suppressing thermal runaway of a power battery according to the present invention. Among them, 1-thermal sheet, 2-gas generating structure, 3-power battery jacket, 4-power battery. Detailed Implementation

[0020] The technical solution of the present invention will be further explained and described below with reference to the accompanying drawings.

[0021] See Figure 1-2 The present invention provides a jacket for suppressing thermal runaway of a power battery, comprising: a thermistor 1, a gas generating structure 2, a power battery jacket 3, and a power battery 4. The power battery 4 is disposed inside the power battery jacket 3. The gas generating structure 2 is provided in the jacket cavity of the power battery jacket 3. The upper wall of the jacket cavity of the power battery jacket 3 has evenly distributed through-holes formed by stamping, and the thermistor 1 is filled in the holes. When the power battery 4 experiences thermal runaway, the power battery 4 transfers heat to the thermistor 1 and the gas generating structure 2 on the power battery jacket 3. The thermistor 1 in the holes volatilizes, meaning the present invention employs a thermal triggering mechanism that can actively detect thermal runaway of the power battery 4 without external power supply or signal input. The gas generating structure 2 undergoes a thermal decomposition reaction, producing a large amount of inert gas and particulate solids, forming a high-density aerosol. The aerosol overflows from the openings of the volatilized thermistor 1, covering the thermally runaway power battery 4, rapidly reducing the temperature of the power battery, achieving rapid fire suppression, and suppressing thermal runaway of the power battery 4.

[0022] In one technical solution of the present invention, the heat-sensitive sheet 1 comprises: 80%~85% by mass of natural dextrorotatory camphor, 12%~14% by mass of ethyl hydroxyacetate, and the remainder being a lactic acid oligomer with a molecular weight of 800~1200. Specifically, the preparation process of the heat-sensitive sheet 1 is as follows: i: Weigh out natural dextrorotatory camphor, ethyl glycolate and lactic acid oligomer respectively; ii: Grind natural dextrorotatory camphor and lactic acid oligomer separately, add ethyl hydroxyethyl dropwise to the ground lactic acid oligomer, and grind until uniformly mixed to obtain a mixed powder; iii: Add the ground natural dextrorotatory camphor to the mixed powder in portions, and grind until uniformly mixed to obtain a particle size of Thermosensitive powder; iv: Fill the cylindrical mold with the thermal powder. Specifically, the cylindrical mold is 1mm high and consists of a convex mold and a concave mold. Lightly wipe the release agent on the inner wall of the concave mold, fill the cavity of the concave mold with the thermal powder, and gently scrape it flat with a scraper to ensure uniform thickness. Place the convex mold in, slowly increase the pressure, press it under a pressure of 1~3MPa for 10~30s, and then slowly release the pressure. After demolding, the thermal sheet 1 is obtained, which can avoid cracks on the thermal sheet 1.

[0023] In one technical solution of the present invention, the diameter of the thermal pad 1 is 1-3 mm, which is 0.1 mm larger than the diameter of the opening. The thermal pad 1 is filled into the opening by extrusion, ensuring the reliability of the thermal pad 1's fixation and the consistency of triggering. The natural dextrorotatory camphor in the thermal pad 1 sublimates rapidly at 120-180°C and completely overflows in gaseous form. Ethyl hydroxyethyl evaporates rapidly at 120-150°C and completely overflows in gaseous form. Simultaneously, the lactic acid oligomer is decomposed into small molecules, which, due to their low content, are carried away by the gas, leaving no solid residue and preventing blockage of the overflow pathway of the large amount of gas produced by the gas generating structure 2. Furthermore, the natural dextrorotatory camphor in the thermal pad 1 generates irritating gas during evaporation, serving as a warning and avoiding secondary risks. Secondly, because the particle size of the thermal powder in the present invention is... It has the advantages of large specific surface area, short internal diffusion path and fast heat transfer, which is conducive to the rapid and complete removal of natural dextrorotatory camphor, ethyl hydroxyacetate and lactic acid oligomers, while avoiding the gas overflow difficulties and boiling phenomenon caused by ultrafine powder.

[0024] In one technical solution of the present invention, the gas generating structure 2 comprises: 30%~45% by mass of cerium ammonium nitrate, 5%~15% by mass of ammonium perchlorate, 5%~15% by mass of boron nanoparticles, 2%~8% by mass of polyethylene glycol, 10%~15% by mass of hydroxyapatite, and the remainder being hydrated vermiculite. Specifically, the preparation process of the gas generating structure 2 is as follows: cerium ammonium nitrate, ammonium perchlorate, boron nanoparticles, polyethylene glycol, hydroxyapatite, and hydrated vermiculite are mixed sequentially and ground evenly to obtain a particle size of [missing information]. Gas generation structure 2.

[0025] In gas generating structure 2, ammonium perchlorate and cerium ammonium nitrate act as strong oxidants, decomposing upon heating at 120-180°C to release large amounts of active oxygen. , , and etc.; as a high-energy combustible component, nano-boron powder will undergo a violent oxidation reaction with the active oxygen released from the decomposition of strong oxidants at high temperatures: This process not only consumes reactive oxygen species but also releases a large amount of heat of reaction, providing a heat source for the further decomposition of gaseous structure 2, while simultaneously generating... Particulate matter is also an important component of fire extinguishing aerosols; polyethylene glycol, as an organic binder, decomposes upon heating, producing... The gas, along with other gases, replenishes the inert gas components of the aerosol. Simultaneously, it regulates the reaction rate, controlling the contact area and reaction interface between the oxidant and combustible components, thereby modulating the intensity of the reaction. Hydroxyapatite and hydrated vermiculite serve as inorganic functional fillers. Hydrated vermiculite dehydrates to release water vapor, diluting the combustible gas and cooling it. Hydroxyapatite, along with... , , Gases and When solid particles form high-temperature stable, high specific surface area solid particles, a large amount of inert gas is eventually generated. , and Micron-nano scale solid particles and Together, they form a high-density, high-efficiency aerosol, which is rapidly and smoothly released onto the power battery 4 through openings in the upper wall of the power battery jacket 3. This isolates oxygen, cools and dilutes flammable gases, achieving highly efficient fire extinguishing. Simultaneously, this aerosol leaves no toxic residue, is environmentally friendly, and is suitable for the enclosed environment of the power battery 4. In this invention, the particle size of the gas generating structure 2 is 3~20 mm. It has high kinetic characteristics and mass transfer efficiency, which helps to form high-density, highly dispersed, and efficient fire extinguishing aerosols, achieving full-dimensional coverage without dead angles.

[0026] In one technical solution of the present invention, the width of the jacket cavity of the power battery jacket 3 satisfies:

[0027] in, This indicates the width of the jacket cavity of the power battery jacket 3. The maximum heat release during thermal runaway of power battery 4 can be calculated from the cell energy density and capacity of power battery 4. This represents an empirical coefficient, with a value range of 0.02. ~5 By designing the width of the jacket cavity, it is ensured that the aerosol generated by the gas generating structure 2 can completely suppress the thermal runaway of the power battery 4.

[0028] In one technical solution of the present invention, the power battery 4 and the inner wall of the power battery jacket 3 are in gapless mechanical contact to reduce thermal resistance and achieve rapid heat conduction. The power battery jacket 3 uses a material with a thermal conductivity of not less than [insert value here]. The thermally conductive material can be a high thermal conductivity metal material such as aluminum, aluminum alloy or copper alloy, or a graphene-modified high thermal conductivity polymer material, so that when the power battery 4 thermally runs away, the heat is quickly transferred to the thermistor 1 and gas generating structure 2 on the power battery jacket 3, shortening the response time.

[0029] When thermal runaway occurs in the power battery 4, this invention transfers heat to the thermistor 1 and gas generating structure 2 on the power battery jacket 3. The thermistor 1 in the opening evaporates, and the gas generating structure 2 undergoes a thermal decomposition reaction to form a high-density aerosol. The aerosol overflows from the opening of the evaporating thermistor 1 and covers the thermally runaway power battery 4. The aerosol is suspended for 15-20 minutes after atomization, which greatly improves the suppression efficiency of thermal runaway in the power battery 4. Meanwhile, it leaves no toxic residues such as cyanide or heavy metals after combustion, has a neutral pH value, is suitable for the sealed environment of power battery 4, and complies with the GB 39031-2020 electric vehicle battery safety standard.

[0030] This invention, through thermal sensing, can quickly suppress thermal runaway of the power battery 4 as long as the temperature of the power battery 4 exceeds 120°C. It can achieve active prevention and control in the early stage of thermal runaway of the power battery 4, improve the timeliness and effectiveness of thermal runaway suppression of the power battery 4, and at the same time, it can comprehensively suppress thermal runaway of the power battery 4 in scenarios such as heating, overcharging, puncture, short circuit, compression and over-discharge.

[0031] Example 1 This embodiment verifies the effect of the component content in thermistor 1 on suppressing thermal runaway of the power battery. The component content of thermistor 1 is shown in Table 1. Natural dextrorotatory camphor and lactic acid oligomers were ground separately. Ethyl hydroxyethyl was added dropwise to the ground lactic acid oligomers, and the mixture was ground until homogeneous to obtain a mixed powder. The ground natural dextrorotatory camphor was then added to the mixed powder in portions, and the mixture was ground until homogeneous to obtain a particle size of [missing information]. Thermosensitive powder was filled into a cylindrical mold and pressed under a pressure of 2 MPa for 20 seconds. After demolding, thermosensitive sheet 1 was obtained. The gas generating structure 2 of the experimental and control groups had the same component content. 40% (w / w) of cerium ammonium nitrate, 10% (w / w) of ammonium perchlorate, 10% (w / w) of nano-boron powder, 5% (w / w) of polyethylene glycol, 10% (w / w) of hydroxyapatite, and 25% (w / w) of hydrated vermiculite were mixed sequentially and ground evenly to obtain a particle size of [missing information]. Gas generation structure 2.

[0032] Table 1: Effects of the content of each component in the thermal sensor 1 of the experimental and control groups on suppressing thermal runaway of the power battery

[0033] The content of each component in thermal sheet 1 is a mass fraction. The power battery 4 is placed inside the power battery jacket 3. The jacket cavity of the power battery jacket 3 is equipped with the aforementioned gas generating structure 2. The upper wall of the jacket cavity of the power battery jacket 3 has evenly distributed through-holes, and the aforementioned thermistor 1 is filled into the through-holes. A thermal runaway test is conducted in a battery thermal runaway test chamber to calculate the thermal runaway suppression efficiency. It can be seen that the thermal runaway suppression efficiency of the control group is significantly lower than that of the experimental group, and the thermal runaway suppression efficiency of the experimental group is higher than 90%, which meets the GB 39031-2020 electric vehicle battery safety standard.

[0034] Thermal runaway suppression efficiency The calculation process is as follows:

[0035] in, This indicates the highest temperature of uncontrolled thermal runaway, expressed in °C. The highest temperature of thermal runaway in the experimental or control group is expressed in °C; 25 represents the set ambient temperature in °C.

[0036] Furthermore, as shown in controls 1 and 2, too little or too much natural dextrorotatory camphor can lead to delayed or excessive volatilization triggering at 120-180℃, affecting the response speed of the thermistor 1 and thus impacting the thermal runaway suppression efficiency of the power battery. As shown in controls 3-4, too little or too much ethyl hydroxyacetate can affect the volatilization rate, thereby disrupting the synergistic volatilization effect with natural dextrorotatory camphor. Controls 5 and 6 further adjusted the content of lactic acid oligomers. When there are no lactic acid oligomers, the adhesion between the thermistor powders is insufficient, resulting in cracks during the molding process of the thermistor 1 and affecting the sealing of the upper wall of the jacket cavity at low temperatures. When the content of lactic acid oligomers is too high, solid residues remain when the thermistor 1 volatilizes, affecting the release of aerosols.

[0037] Example 2 This embodiment verifies the effect of the particle size of the thermistor powder in thermistor sheet 1 on suppressing thermal runaway of the power battery. Specifically, 82% by mass of natural dextrorotatory camphor and 5% by mass of lactic acid oligomer were ground separately. 13% by mass of ethyl hydroxyacetate was added dropwise to the ground lactic acid oligomer, and the mixture was ground until homogeneous to obtain a mixed powder. The ground natural dextrorotatory camphor was then added to the mixed powder in portions, and the mixture was ground until homogeneous. The particle size of the thermistor powder in thermistor sheet 1 is shown in Table 2. Thermosensitive powder was filled into a cylindrical mold and pressed under a pressure of 2 MPa for 20 seconds. After demolding, thermosensitive sheet 1 was obtained. The gas generating structure 2 of the experimental and control groups had the same component content. 40% (w / w) of cerium ammonium nitrate, 10% (w / w) of ammonium perchlorate, 10% (w / w) of nano-boron powder, 5% (w / w) of polyethylene glycol, 10% (w / w) of hydroxyapatite, and 25% (w / w) of hydrated vermiculite were mixed sequentially and ground evenly to obtain a particle size of [missing information]. Gas generation structure 2.

[0038] Table 2: Effect of the particle size of the thermal powder in the thermal sheet 1 on the suppression of thermal runaway of the power battery in the experimental and control groups.

[0039] The power battery 4 is placed inside the power battery jacket 3. The jacket cavity of the power battery jacket 3 is equipped with the aforementioned gas generating structure 2. The upper wall of the jacket cavity of the power battery jacket 3 has evenly distributed through-holes, and the aforementioned thermistor 1 is filled into these holes. Thermal runaway experiments were conducted in a battery thermal runaway test chamber. The results showed that the thermal runaway suppression efficiency of the control group was significantly lower than that of the experimental group, and the thermal runaway suppression efficiency of the experimental group was higher than 90%, meeting the GB 39031-2020 electric vehicle battery safety standard. The experimental group 6 contained particles with a diameter of 5~30 mm. The thermally sensitive powder has a moderate specific surface area, a short internal diffusion path, and a fast heat transfer rate, enabling natural dextrorotatory camphor and ethyl hydroxyacetate to sublimate and volatilize rapidly and completely at 120~180℃. This ensures that the opening channels on the upper wall of the jacket cavity are completely opened, eliminating the risk of blockage. After volatilization, there is no solid residue, and it will not block the aerosol release pathway generated by gas generation structure 2, thus guaranteeing the thermal runaway suppression efficiency of the power battery. In control group 7, the particle size of the thermally sensitive powder is too small. Due to the agglomeration and compaction effect, gas overflow is hindered, resulting in a decrease in the thermal runaway suppression efficiency of the power battery. In control group 8, the particle size of the thermally sensitive powder is too large, resulting in insufficient heat transfer and volatilization, which also hinders gas overflow and leads to a decrease in the thermal runaway suppression efficiency of the power battery.

[0040] Example 3 This embodiment verifies the effect of the pressing process of the thermistor sheet 1 on suppressing thermal runaway of the power battery. Specifically, 82% by mass of natural dextrorotatory camphor and 5% by mass of lactic acid oligomer were ground separately. 13% by mass of ethyl hydroxyacetate was added dropwise to the ground lactic acid oligomer, and the mixture was ground until homogeneous to obtain a mixed powder. The ground natural dextrorotatory camphor was then added to the mixed powder in portions, and the mixture was ground until homogeneous to obtain a particle size of [missing information]. Thermosensitive powder was filled into cylindrical molds. The pressing parameters of thermosensitive sheet 1 are shown in Table 3. After demolding, thermosensitive sheet 1 was obtained. The content of each component in the gas generating structure 2 of the experimental group and the control group was the same. 40% cerium ammonium nitrate, 10% ammonium perchlorate, 10% boron nanoparticles, 5% polyethylene glycol, 10% hydroxyapatite, and 25% hydrated vermiculite were mixed in sequence and ground evenly to obtain a particle size of [missing information]. Gas generation structure 2.

[0041] Table 3: Effects of the pressing parameters of the thermal sensor 1 on suppressing thermal runaway of the power battery in the experimental and control groups.

[0042] The power battery 4 is placed inside the power battery jacket 3. The jacket cavity of the power battery jacket 3 is equipped with the aforementioned gas generating structure 2. The upper wall of the jacket cavity of the power battery jacket 3 has evenly distributed through-holes, and the aforementioned thermistor 1 is filled into the through-holes. Thermal runaway experiments were conducted in a battery thermal runaway test chamber. It was found that the thermal runaway suppression efficiency of the control group was significantly lower than that of the experimental group, and the thermal runaway suppression efficiency of the experimental group was higher than 90%, which meets the GB 39031-2020 electric vehicle battery safety standard.

[0043] Furthermore, in experimental groups 6-11, the thermistor 1 maintained a dense and uniform structure, consistent trigger response, and no cracks or defects during the pressing process, ensuring long-term reliability. In control group 9, the thermistor 1 was pressed under too low pressure, and in control group 11, the pressing time was too short, both of which resulted in a loose structure of the thermistor. The loose structure is prone to breakage during use, leading to filling failure and affecting the thermal runaway suppression efficiency of the power battery. In control group 10, the thermistor 1 was pressed under too high pressure, and in control group 12, the pressing time was too long, resulting in excessive internal densification of the thermistor, which hindered gas overflow, slowed the trigger response, and reduced the thermal runaway suppression efficiency of the power battery.

[0044] Example 4 This embodiment verifies the effect of the content of each component in gas generating structure 2 on suppressing thermal runaway of the power battery. Specifically, 82% by mass of natural dextrorotatory camphor and 5% by mass of lactic acid oligomer were ground separately. 13% by mass of ethyl hydroxyacetate was added dropwise to the ground lactic acid oligomer, and the mixture was ground until homogeneous to obtain a mixed powder. The ground natural dextrorotatory camphor was then added to the mixed powder in portions, and the mixture was ground until homogeneous to obtain a particle size of [missing information]. Thermosensitive powder was filled into cylindrical molds and pressed under a pressure of 2 MPa for 20 seconds. After demolding, thermosensitive sheet 1 was obtained. The content of each component in gas generating structure 2 is shown in Table 4. Cerium ammonium nitrate, ammonium perchlorate, nano boron powder, polyethylene glycol, hydroxyapatite, and hydrated vermiculite were mixed in sequence and ground evenly to obtain a particle size of [missing information]. Gas generation structure 2.

[0045] Table 4: Effects of the content of each component in gas generation structure 2 on suppressing thermal runaway of power battery in experimental and control groups.

[0046] The content of each component in gas generating structure 2 is a mass fraction. The power battery 4 is placed inside the power battery jacket 3. The jacket cavity of the power battery jacket 3 is equipped with the aforementioned gas generating structure 2. The upper wall of the jacket cavity of the power battery jacket 3 has evenly distributed through-holes, and the aforementioned thermistor 1 is filled into the through-holes. Through thermal runaway testing in a battery thermal runaway test chamber, it was found that the thermal runaway suppression efficiency of the control group was significantly lower than that of the experimental group, and the thermal runaway suppression efficiency of the experimental group was higher than 90%, which meets the GB 39031-2020 electric vehicle battery safety standard.

[0047] Furthermore, in control group 13, the content of cerium ammonium nitrate was too low, resulting in insufficient oxygen supply and inadequate oxidation reaction with the nano-boron powder. This led to insufficient aerosol generation, affecting the aerosol's ability to cover the thermally runaway battery and reducing its thermal runaway suppression efficiency. In control group 14, the content of cerium ammonium nitrate was too high, with excessive oxidant causing an overly vigorous reaction and a sudden release of a large amount of heat, exacerbating thermal runaway. In control group 15, the content of ammonium perchlorate was too low, resulting in a slow reaction rate and delayed aerosol generation, failing to cover the thermally runaway battery in time to suppress thermal runaway. In control group 16, the content of ammonium perchlorate was too high, resulting in an overly fast reaction rate and a sudden generation of a large amount of gas, causing a sudden increase in pressure in the jacket cavity, which could damage the structure and exacerbate the thermal runaway of the battery. In control group 17, the low content of boron nanoparticles resulted in insufficient heat of reaction, leading to a small amount of aerosol generation. This affected the aerosol's ability to cover the thermally runaway battery and reduced its thermal runaway suppression efficiency. In control group 18, the high content of boron nanoparticles caused an overly vigorous reaction, releasing a large amount of heat instantaneously, exacerbating thermal runaway and reducing the suppression efficiency to 19.2%. In control group 19, the low content of polyethylene glycol (PEG) resulted in a loose and brittle structure, affecting aerosol generation. In control group 20, the high content of PEG led to excessive organic components, producing large amounts of black smoke and CO during combustion, increasing toxicity and consuming excessive oxygen. In control group 21, the low content of hydroxyapatite resulted in insufficient aerosol density and weak coverage. In control group 22, the high content of hydroxyapatite led to excessive solid particles, blocking gas escape channels and hindering aerosol release.

[0048] Example 5 This embodiment verifies the effect of the particle size of the gas generating structure 2 on suppressing thermal runaway of the power battery. Specifically, 82% by mass of natural dextrorotatory camphor and 5% by mass of lactic acid oligomer were ground separately. 13% by mass of ethyl hydroxyacetate was added dropwise to the ground lactic acid oligomer, and the mixture was ground until homogeneous to obtain a mixed powder. The ground natural dextrorotatory camphor was then added to the mixed powder in portions, and the mixture was ground until homogeneous to obtain a particle size of [missing information]. Thermosensitive powder was filled into cylindrical molds and pressed under a pressure of 2 MPa for 20 s. After demolding, thermosensitive sheet 1 was obtained. The contents of each component in the gas generating structure 2 of the experimental group and the control group were the same. 40% cerium ammonium nitrate, 10% ammonium perchlorate, 10% boron nanoparticles, 5% polyethylene glycol, 10% hydroxyapatite, and 25% hydrated vermiculite were mixed in sequence and ground evenly to obtain gas generating structure 2. Its particle size is shown in Table 5.

[0049] Table 5: Effect of particle size of gas generating structure 2 on suppressing thermal runaway of power battery in experimental and control groups

[0050] The power battery 4 is placed inside the power battery jacket 3. The jacket cavity of the power battery jacket 3 is equipped with the aforementioned gas generating structure 2. The upper wall of the jacket cavity of the power battery jacket 3 has evenly distributed through-holes, and the aforementioned thermistor 1 is filled into the through-holes. Through thermal runaway testing in a battery thermal runaway test chamber, it was found that the thermal runaway suppression efficiency of the control group was significantly lower than that of the experimental group, and the thermal runaway suppression efficiency of the experimental group was higher than 90%, which meets the GB 39031-2020 electric vehicle battery safety standard.

[0051] In experimental group 17, the particle size was 3~20 mm. The gas generating structure 2 can achieve efficient mass transfer, producing agglomerated aerosols with high dispersion, which will not block the openings on the upper wall of the jacket cavity, ensuring smooth aerosol release and improving the thermal runaway suppression efficiency of the electric battery. In the control group 23, the particle size of the gas generating structure 2 is too small, which increases the agglomeration effect, resulting in impeded mass transfer. Solid particles are prone to blocking the openings, hindering aerosol release. In the control group 24, the particle size of the gas generating structure 2 is too large, resulting in insufficient reaction and reduced coverage of the electric battery, thus greatly reducing the thermal runaway suppression efficiency of the power battery.

[0052] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A jacket for suppressing thermal runaway of a power battery, characterized in that, include: The device includes a thermistor, a gas generating structure, a power battery jacket, and a power battery. The power battery is disposed inside the power battery jacket. The power battery jacket cavity is provided with a gas generating structure. The upper wall of the power battery jacket cavity has evenly distributed through-holes. The thermistor is filled in the through-holes. When the power battery experiences thermal runaway, the power battery transfers heat to the thermistor and gas generating structure on the power battery jacket. The thermistor in the opening evaporates, and the gas generating structure decomposes to produce aerosol. The aerosol overflows from the opening and covers the thermally runaway power battery, suppressing the thermal runaway. The gas generating structure comprises: 30% to 45% ammonium cerium nitrate, 5% to 15% ammonium perchlorate, 5% to 15% boron nanoparticles, 2% to 8% polyethylene glycol, 10% to 15% hydroxyapatite, and the remainder being hydrated vermiculite. The heat-sensitive sheet comprises: 80% to 85% by mass of natural dextrorotatory camphor, 12% to 14% by mass of ethyl hydroxyacetate, and the remainder being lactic acid oligomers with a molecular weight of 800 to 1200.

2. The jacket for suppressing thermal runaway of a power battery according to claim 1, characterized in that, The preparation process of the thermal sheet is as follows: i: Weigh out natural dextrorotatory camphor, ethyl glycolate and lactic acid oligomer respectively; ii: Grind natural dextrorotatory camphor and lactic acid oligomer separately, add ethyl hydroxyethyl dropwise to the ground lactic acid oligomer, and grind until uniformly mixed to obtain a mixed powder; iii: Add the ground natural dextrorotatory camphor to the mixed powder in portions, and grind until uniformly mixed to obtain a particle size of Thermosensitive powder; iv: Thermosensitive powder is filled into a cylindrical mold and pressed under a pressure of 1~3MPa for 10~30s. After demolding, the thermosensitive sheet is obtained.

3. A jacket for suppressing thermal runaway of a power battery according to claim 1 or 2, characterized in that, The diameter of the thermal sheet is 1~3mm, and the diameter of the thermal sheet is 0.1mm larger than the diameter of the opening. The thermal sheet is filled into the opening by extrusion.

4. A jacket for suppressing thermal runaway of a power battery according to claim 1, characterized in that, The preparation process of the gas generating structure is as follows: Cerium ammonium nitrate, ammonium perchlorate, nano-boron powder, polyethylene glycol, hydroxyapatite, and hydrated vermiculite are mixed sequentially and ground evenly to obtain a particle size of [missing information]. The gas generation structure.

5. A jacket for suppressing thermal runaway of a power battery according to claim 1, characterized in that, The width of the jacket cavity of the power battery jacket satisfies: in, This indicates the width of the jacket cavity of the power battery jacket. This indicates the maximum heat release during thermal runaway of the power battery. This represents an empirical coefficient, with a value range of 0.

02. ~5 .

6. A jacket for suppressing thermal runaway of a power battery according to claim 1, characterized in that, The power battery and the inner wall of the power battery jacket are in a gapless mechanical contact.

7. A jacket for suppressing thermal runaway of a power battery according to claim 1, characterized in that, The power battery jacket uses a thermal conductivity of not less than Thermally conductive materials.

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