Super-pressure-resistant thermal insulation material as well as preparation method and application thereof

Abstract

The invention provides a super-pressure-resistant thermal insulation material as well as a preparation method and application thereof, and relates to the field of thermal insulation protection. The super pressure-resistant thermal insulation material is prepared from the following components in parts by weight: 17.4 to 22.8 parts of a binding agent, 17.4 to 22.8 parts of hollow glass microspheres, 26.7 to 34.9 parts of aerogel paste and 15.1 to 34.9 parts of mullite nanofiber dispersion liquid. According to the invention, the mullite nanofibers are introduced to have a synergistic effect with the hollow glass microspheres and the aerogel particles, so that the heat-insulating material with excellent mechanical properties and heat-insulating properties is prepared. The compression strength of the super-pressure-resistant thermal insulation material is at least 0.8 MPa, the heat conductivity coefficient is about 0.03 W.m <-1 >. K <-1 >, and the super-pressure-resistant thermal insulation material has a good thermal insulation effect.

Description

Technical Field

[0001] The present invention relates to the field of thermal insulation and protection, and in particular to a super-pressure-resistant thermal insulation material and a preparation method and application thereof. Background Art

[0002] Today, energy crisis and environmental pollution are becoming increasingly serious. Electricity, as a clean energy source, is receiving more and more attention and importance. In this context, lithium batteries are widely used in aerospace, energy storage power stations, electric vehicles and other fields due to their advantages such as high energy density, long cycle life and no memory effect. However, due to the extremely active chemical substances inside lithium batteries, under extreme conditions such as thermal abuse and mechanical abuse, a series of violent exothermic reactions will occur inside the battery, eventually leading to the occurrence of thermal runaway, releasing a large amount of heat and flammable gases, which can easily cause fires or even explosions, seriously threatening the safety of life and property. What is more serious is that in actual applications, lithium batteries are usually used in groups in the form of battery clusters. Once a battery in the battery is in thermal runaway, the high temperature and heat generated by the thermal runaway battery will quickly spread to the adjacent batteries, inducing the spread of thermal runaway, further exacerbating the scale and risk of the accident. This chain effect greatly limits the further promotion and application of lithium batteries in areas with high safety requirements.

[0003] Therefore, a new thermal insulation material is needed that is particularly suitable for lithium battery modules. Summary of the invention

[0004] In order to solve the above-mentioned deficiencies in the prior art, the present invention provides a super pressure-resistant thermal insulation material, which has good mechanical, flame-retardant and thermal insulation properties.

[0005] Another object of the present invention is to provide a method for preparing the above-mentioned super-pressure-resistant thermal insulation material.

[0006] The present invention also provides application of the super-pressure-resistant heat-insulating material.

[0007] In order to achieve the above object, the technical solution of the present invention is:

[0008] A super-pressure-resistant heat-insulating material comprises the following components in weight proportion: 17.4 to 22.8 parts of a binder, 17.4 to 22.8 parts of hollow glass microspheres, 26.7 to 34.9 parts of an aerogel paste, and 15.1 to 34.9 parts of a mullite nanofiber dispersion.

[0009] Preferably, the binder is one of epoxy resin, phenolic resin, water-based acrylic emulsion and water-based polyurethane.

[0010] Preferably, the hollow glass microspheres have a hollow structure and an average particle size between 20 and 70 microns, and a bulk density of 0.075 to 0.35 g / cm3 .

[0011] Preferably, the aerogel paste comprises the following components in weight proportion: 65.8-84.6 parts of deionized water, 4.0-5.1 parts of auxiliary agent, 0.20-0.34 parts of cellulose, and 10.0-30.0 parts of aerogel powder.

[0012] Preferably, the auxiliary agent includes the following components in weight proportion: 20-30 parts of dispersant, 20-30 parts of coupling agent, 20-30 parts of wetting agent, and 10-20 parts of defoaming agent.

[0013] Preferably, the dispersant is polyacrylate ammonium salt anion 1124 dispersant and / or polycarboxylate sodium salt anion 5040 dispersant;

[0014] Preferably, the coupling agent is a silane coupling agent, preferably one or a mixture of γ-aminopropyltriethoxysilane (KH-550), γ-glycidyloxypropyltrimethoxysilane (KH-560), and γ-methacryloxypropyltrimethoxysilane (KH-570);

[0015] Preferably, the wetting agent is one or a mixture of alkylphenol nonionic surfactant complex, anionic surfactant, nonionic low foam wetting agent; preferably one or more of PE-100, sodium diisooctyl sulfosuccinate (OT-75) and CF-10;

[0016] Preferably, the defoaming agent is an aqueous defoaming agent, preferably a mixture of one or more of a polydimethylsiloxane mixture (JT-908), a silicone oil and a high molecular polymer mixture (JT-910), and a silicone and polymer mixture (JT-930).

[0017] Preferably, the cellulose is one of methyl cellulose, ethyl cellulose, hydroxymethyl cellulose and hydroxyethyl cellulose, or a mixture of several thereof.

[0018] Preferably, the aerogel powder is nano-silicon dioxide aerogel powder, the porosity of the nano-silicon dioxide aerogel powder is greater than 90%, the average particle size of the nano-silicon dioxide aerogel powder is 5-50 microns, and the bulk density is 0.06-0.12 g / cm 3 .

[0019] Preferably, the mullite nanofiber dispersion comprises the following components in weight ratio: 5-10 parts of mullite nanofibers and 90-95 parts of deionized water.

[0020] Preferably, the mullite nanofibers are fibers prepared from a precursor solution through an electrospinning process;

[0021] The precursor solution comprises the following components in weight proportion: 50.2-57.2 parts of deionized water, 12.0-13.7 parts of aluminum chloride hexahydrate, 25.4-29.0 parts of aluminum isopropoxide, 0-12.1 parts of tetraethyl orthosilicate, and 0.1-0.3 parts of polymer; wherein the polymer is a mixture of one or more of polyethylene oxide, polyvinyl alcohol, and polyethylene glycol, and the molecular weight of the polymer is 600,000-1000,000.

[0022] Preferably, the super pressure-resistant thermal insulation material further comprises 3.4 parts to 4.6 parts of a flame retardant additive, wherein the flame retardant additive is one or a mixture of several of ammonium polyphosphate, aluminum hydroxide and magnesium hydroxide.

[0023] The method for preparing the above-mentioned super-pressure-resistant heat-insulating material comprises the following steps:

[0024] S1. Mixing: adding components in corresponding proportions to the binder according to the ratio, and mixing them evenly to obtain a mixture;

[0025] S2. Shaping: The mixture obtained in S1 is shaped, and then placed in a drying oven, and dried at 60-100° C. for 10-14 hours to obtain the ultra-pressure-resistant thermal insulation material.

[0026] Preferably, the aerogel paste is prepared by the following steps:

[0027] S01: Add the auxiliary agent and cellulose to deionized water according to the ratio, stir evenly, then add the corresponding mass fraction of nano-silicon dioxide aerogel powder, and continue stirring until it becomes a paste, so as to obtain the aerogel paste.

[0028] Preferably, the mullite nanofiber dispersion is prepared by the following steps:

[0029] S02: Prepare a precursor solution: add aluminum chloride hexahydrate, aluminum isopropoxide, and tetraethyl orthosilicate into deionized water according to the ratio, stir for 10 to 14 hours, add an appropriate amount of polymer, and stir again for 2 to 4 hours to obtain a precursor solution;

[0030] S03: preparing mullite nanofibers: electrostatically spinning the precursor solution obtained in S02; collecting the fiber felt after spinning, calcining it, and cooling it to obtain mullite nanofibers;

[0031] S04: preparing fiber dispersion: cutting the calcined mullite nanofiber felt into small pieces, adding them into deionized water, and using a disperser to disperse them at a speed of 2000-4000 rpm for 4-8 minutes to obtain a fiber dispersion.

[0032] Preferably, the calcination temperature is not less than 1300° C. and the calcination time is 30 min to 90 min.

[0033] Preferably, the heating rate of the calcination treatment is 5-10 °C / min.

[0034] The application of the above-mentioned ultra-pressure-resistant heat-insulating material in lithium battery modules.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. In the present invention, we introduced mullite nanofibers, which work synergistically with hollow glass microspheres and aerogel particles to prepare thermal insulation materials with excellent mechanical properties and thermal insulation properties. Compared with traditional materials, the thermal insulation materials in the present invention not only have a wide range of raw material sources and simple processing technology, but also can flexibly adjust the shape and size according to actual needs. It is suitable for thermal runaway protection of lithium batteries of different specifications, significantly reducing the battery insulation cost and improving the universality of the material. The ultra-pressure insulation material of the present invention has a compressive strength of at least 0.8 MPa and a thermal conductivity of approximately 0.03 W·m -1 ·K -1 , has a good thermal insulation effect.

[0037] 2. In order to meet the application needs of lithium battery modules with higher fire risks, flame retardants are added to the materials, and the flame retardant properties reach V-0 level, giving them excellent flame retardant properties and further reducing the combustion risk of the battery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a scanning electron microscope image of the mullite nanofiber prepared in Example 3.

[0039] Figure 2 and Figure 3 This is a scanning electron microscope image of the super-pressure-resistant thermal insulation material prepared in Example 3.

[0040] Figure 4 and Figure 5 This is a scanning electron microscope image of the pores of aerogel particles in the ultra-pressure-resistant thermal insulation material prepared in Example 3. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0042] The raw materials used in the embodiments of the present invention are commercially available unless otherwise specified.

[0043] Example 1

[0044] A super-pressure-resistant heat-insulating material comprises the following raw materials by mass ratio: 22.75 parts of acrylic emulsion, 22.75 parts of hollow glass microspheres, 34.84 parts of aerogel paste, and 15.11 parts of mullite nanofiber dispersion. The hollow glass microspheres have an average particle size of 70 microns and a bulk density of 0.075 g / cm3.

[0045] The aerogel paste includes the following raw materials by mass: 65.8 parts of deionized water, 4.0 parts of additives, 0.2 parts of cellulose, and 30.0 parts of aerogel powder. The preparation process is as follows: S01: Add four additives and cellulose to deionized water according to the ratio, stir evenly, add the corresponding mass parts of aerogel powder, continue stirring until it becomes a paste, and then the aerogel paste can be obtained. The additives include the following raw materials by mass: 28.5 parts of dispersant, 28.5 parts of coupling agent, 28.5 parts of wetting agent, and 14.5 parts of defoaming agent. The cellulose is commercial extra-high viscosity industrial grade hydroxyethyl cellulose; the aerogel powder is commercial nano-silica aerogel powder with a porosity of >90%, an average particle size of 5 microns, and a bulk density of 0.06 g / cm3. The dispersant is polyacrylate ammonium salt anion 1124 dispersant, the coupling agent is silane coupling agent γ-aminopropyl triethoxysilane (KH-550), the wetting agent is a non-ionic surfactant complex (PE-100), and the defoaming agent is a mixture of siloxane and polymer (JT-930).

[0046] The mullite fiber dispersion includes the following raw materials by weight: 10 parts of mullite nanofibers and 90 parts of deionized water. The mullite fiber dispersion is prepared by the following preparation method:

[0047] S02, prepare a precursor solution: add aluminum chlorohexahydrate, aluminum isopropoxide, and tetraethyl orthosilicate to deionized water according to the ratio, stir for 12 hours, add the polymer, and stir again for 2 hours to obtain a precursor solution. The precursor solution includes the following raw materials by mass: 50.28 parts of deionized water, 12.07 parts of aluminum chlorohexahydrate, 25.48 parts of aluminum isopropoxide, 12.07 parts of tetraethyl orthosilicate, and 0.1 parts of polymer; the polymer is polyethylene oxide.

[0048] S03, preparation of mullite nanofibers: inject the precursor solution into a syringe and install it on the propulsion device of the electrospinning machine for electrospinning. During the spinning process, a high voltage of 20 kV is applied, the propulsion speed is 5 mL / h, and the spinning distance is 15 cm. After the spinning is completed, the fiber felt is collected and placed in a muffle furnace. The temperature is increased to 1300 ℃ at a heating rate of 5 ℃ / min and kept for 1 hour. The mullite nanofibers are obtained by cooling with the furnace.

[0049] S04. Prepare fiber dispersion: cut the calcined mullite nanofiber felt into small pieces, add them into deionized water, and use a disperser to disperse them at a speed of 3000 rpm for 5 minutes to obtain a fiber dispersion.

[0050] The preparation process of the super-pressure-resistant heat-insulating material of this embodiment is as follows:

[0051] S1. Mixing: adding aerogel paste, hollow glass microspheres, and mullite nanofiber dispersion to a binder according to a ratio, and mixing them evenly to obtain a mixture;

[0052] S2. Shaping: The mixture obtained in S1 is shaped, and then placed in a drying oven and dried at 80° C. for 12 hours to obtain the ultra-pressure-resistant thermal insulation material.

[0053] Example 2

[0054] The preparation process of this embodiment is the same as that of embodiment 1.

[0055] The difference is that the super-pressure insulation material of this embodiment includes the following raw materials in mass ratio: 22.75 parts of acrylic emulsion, 4.55 parts of flame retardant additive, 22.75 parts of hollow glass microspheres, 34.84 parts of aerogel paste, and 15.11 parts of mullite nanofiber dispersion, wherein the flame retardant additive is commercial ammonium polyphosphate.

[0056] Example 3

[0057] The preparation process of this embodiment is the same as that of embodiment 1.

[0058] The super-pressure-resistant heat-insulating material of this embodiment includes the following raw materials by weight: 19.76 parts of acrylic emulsion, 3.95 parts of flame retardant additive, 19.76 parts of hollow glass microspheres, 30.27 parts of aerogel paste, and 26.24 parts of mullite nanofiber dispersion, wherein the flame retardant additive is commercial ammonium polyphosphate.

[0059] Example 4

[0060] The preparation process of this embodiment is the same as that of embodiment 1.

[0061] The super-pressure-resistant heat-insulating material of this embodiment includes the following raw materials by weight: 17.47 parts of acrylic emulsion, 3.49 parts of flame retardant additive, 17.47 parts of hollow glass microspheres, 26.76 parts of aerogel paste, and 34.81 parts of mullite nanofiber dispersion, wherein the flame retardant additive is commercial ammonium polyphosphate.

[0062] Example 5

[0063] The preparation process of this embodiment is the same as that of embodiment 1.

[0064] The super-pressure insulation material of this embodiment includes the following raw materials by weight: 17.47 parts of epoxy resin, 3.49 parts of magnesium hydroxide, 17.47 parts of hollow glass microspheres, 26.76 parts of aerogel paste, and 34.81 parts of mullite nanofiber dispersion. In step S2 of the preparation process of the super-pressure insulation material, the drying temperature is 60°C and the drying time is 14 hours.

[0065] The aerogel paste includes the following raw materials in mass fractions: 84.56 parts of deionized water, 5.1 parts of auxiliary agents, 0.34 parts of cellulose, and 10.0 parts of aerogel powder. The auxiliary agents include the following raw materials in mass fractions: 20 parts of dispersant, 20 parts of coupling agent, 30 parts of wetting agent, and 10 parts of defoamer. The cellulose is commercial extra-high viscosity industrial grade methyl cellulose; the aerogel powder is commercial nano-silica aerogel powder with a porosity of >90%, an average particle size of 20 microns, and a bulk density of 0.08 g / cm3. The dispersant is polycarboxylate sodium salt anion 5040 dispersant, the coupling agent is γ-glycidyl ether oxypropyl trimethoxy silane (KH-560), the wetting agent is sodium diisooctyl sulfosuccinate (OT-75), and the defoamer is a polydimethylsiloxane mixture.

[0066] The mullite fiber dispersion includes the following raw materials in parts by weight: 5 parts of mullite nanofibers and 95 parts of deionized water. The mullite fiber dispersion is prepared by the following preparation method:

[0067] S02, prepare a precursor solution: add aluminum chlorohexahydrate, aluminum isopropoxide, and tetraethyl orthosilicate to deionized water according to the ratio, stir for 14 hours, add the polymer, and stir again for 3 hours to obtain a precursor solution. The precursor solution includes the following raw materials by mass: 57.11 parts of deionized water, 13.67 parts of aluminum chlorohexahydrate, 29.0 parts of aluminum isopropoxide, 0.02 parts of tetraethyl orthosilicate, and 0.2 parts of polymer; the polymer is polyvinyl alcohol.

[0068] S03. Preparation of mullite nanofibers: Inject the precursor solution into a syringe and install it on the propulsion device of the electrospinning machine for electrospinning. During the spinning process, a high voltage of 20 kV is applied, the propulsion speed is 5 mL / h, and the spinning distance is 15 cm. After the spinning is completed, the fiber felt is collected and placed in a muffle furnace. The temperature is increased to 1400 °C at a heating rate of 7 °C / min and kept warm for 30 minutes. The mullite nanofibers are obtained by cooling with the furnace.

[0069] S04. Prepare fiber dispersion: cut the calcined mullite nanofiber felt into small pieces, add them into deionized water, and use a disperser to disperse them at a speed of 2000 rpm for 8 minutes to obtain a fiber dispersion.

[0070] Example 6

[0071] The preparation process of this embodiment is the same as that of embodiment 1.

[0072] The super-pressure insulation material of this embodiment includes the following raw materials by weight: 17.47 parts of acrylic emulsion, 3.49 parts of aluminum hydroxide, 17.47 parts of hollow glass microspheres, 26.76 parts of aerogel paste, and 34.81 parts of mullite nanofiber dispersion. In step S2 of the preparation process of the super-pressure insulation material, the drying temperature is 100°C and the drying time is 10 hours.

[0073] The aerogel paste includes the following raw materials in mass proportions: 75.2 parts of deionized water, 4.5 parts of auxiliary agents, 0.30 parts of cellulose, and 20.0 parts of aerogel powder. The auxiliary agents include the following raw materials in mass proportions: 25 parts of dispersant, 25 parts of coupling agent, 25 parts of wetting agent, and 20 parts of defoaming agent. The cellulose is commercial extra-high viscosity industrial grade ethyl cellulose; the aerogel powder is commercial nano-silica aerogel powder with a porosity of >90%, an average particle size of 45 microns, and a bulk density of 0.12 g / cm 3 The dispersant is polycarboxylate sodium salt anion 5040 dispersant, the coupling agent is a mixture of γ-aminopropyl triethoxysilane (KH-550) and γ-glycidyloxypropyl trimethoxysilane (KH-560) (mass ratio is 1:1), the wetting agent is an alkylphenol nonionic surfactant complex (PE-100), and the defoaming agent is a mixture of silicone oil and high molecular polymer (JT-910).

[0074] The mullite fiber dispersion includes the following raw materials in parts by weight: 5 parts of mullite nanofibers and 95 parts of deionized water. The mullite fiber dispersion is prepared by the following preparation method:

[0075] S02, prepare a precursor solution: add aluminum chlorohexahydrate, aluminum isopropoxide, and tetraethyl orthosilicate to deionized water according to the ratio, stir for 10 hours, add the polymer, and stir again for 4 hours to obtain a precursor solution. The precursor solution includes the following raw materials by mass: 57.11 parts of deionized water, 12.57 parts of aluminum chlorohexahydrate, 27.1 parts of aluminum isopropoxide, 2.03 parts of tetraethyl orthosilicate, and 0.3 parts of polymer; the polymer is polyethylene glycol.

[0076] S03. Preparation of mullite nanofibers: Inject the precursor solution into a syringe and install it on the propulsion device of the electrospinning machine for electrospinning. During the spinning process, a high voltage of 20 kV is applied, the propulsion speed is 5 mL / h, and the spinning distance is 15 cm. After the spinning is completed, the fiber felt is collected and placed in a muffle furnace. The temperature is increased to 1450 ℃ at a heating rate of 7 ℃ / min and kept for 90 minutes. The mullite nanofibers are obtained by cooling with the furnace.

[0077] S04. Prepare fiber dispersion: cut the calcined mullite nanofiber felt into small pieces, add them into deionized water, and use a disperser to disperse them at a speed of 4000 rpm for 4 minutes to obtain a fiber dispersion.

[0078] Figure 1 is a scanning electron microscope image of the mullite nanofiber prepared in Example 3, Figure 2 and Figure 3 is a scanning electron microscope image of the thermal insulation material obtained in Example 3, Figure 4 and Figure 5 This is a scanning electron microscope image of the pores of aerogel particles in the thermal insulation material prepared in Example 3.

[0079] like Figure 1 As shown, the average diameter of the mullite nanofibers in the present invention is about 227 microns, the fiber length after dispersion is 70-90 μm, and the aspect ratio is 250-450; with its unique high aspect ratio and high flexibility, the mechanical properties of the composite material are significantly enhanced, so that it can still maintain a stable thermal insulation effect when the lithium battery expands. Figure 2 and 3As shown in the figure, hollow glass microspheres form a "filling-bridging" three-dimensional structure under the connection of the binder, and mullite nanofibers are further interwoven as reinforcing brackets to construct a multiple network structure of "fiber-microsphere-binder". The hollow glass microspheres in this structure are like "bridge piers" support, while the binder and mullite fibers together form a stable "bridge" to fix and strengthen the arrangement of the microspheres. When the battery expands slightly during the cycle, the mullite fiber can absorb part of the stress through its own elastic deformation to maintain the integrity of the structure; under the violent expansion caused by thermal runaway, the three-dimensional network structure and fiber reinforcement effect significantly improve the material's compressive resistance, enabling it to maintain most of its thermal insulation function and effectively inhibit the spread of thermal runaway.

[0080] The thermal insulation material of the present invention realizes a multi-scale synergistic thermal insulation effect by combining mullite nanofibers, hollow glass microspheres and aerogel particles, and constructs an efficient thermal barrier structure. In the composite material, the thermal conduction resistance of the material is greatly improved by the interlacing and interface effect between the mullite nanofibers. In addition, the aerogel particles are evenly filled in the gaps between the hollow glass microspheres and the mullite fibers, forming dense interface contact points, thereby further improving the interface thermal resistance and effectively hindering the conduction and diffusion of heat. As the main skeleton of the composite material, the hollow glass microsphere retains its unique hollow structure and has extremely low density and thermal conductivity. The gas barrier inside the hollow microsphere greatly reduces the heat conduction path, and the larger hollow microsphere can be used as a scatterer of thermal radiation, which weakens the propagation of heat in the material by reflecting and scattering thermal radiation energy. In addition, the smaller aerogel particles are filled between the gaps between the hollow glass microspheres to form a tight microscale structure. This multi-layered microstructure not only improves the thermal insulation performance of the material, but also builds multiple thermal resistance layers at the interface, so that heat is reflected, scattered and blocked multiple times inside the material, thus achieving a significant thermal insulation effect. It is worth emphasizing that the pore structure of the aerogel particles is completely preserved during the preparation process and will not be filled with binders ( Figure 4 and Figure 5 ), so its excellent thermal insulation performance is fully utilized. Finally, a highly synergistic multi-scale effect is formed between mullite nanofibers, hollow glass microspheres and aerogel particles. Through microsphere scattering, fiber reinforcement and aerogel filling, an efficient composite thermal insulation material is constructed, which significantly improves the thermal runaway protection effect of lithium battery modules.

[0081] Performance Test:

[0082] The thermal insulation material was tested according to the UL 94 vertical burning test standard and the flame retardant grade of the sample was obtained. The compression performance test was performed according to the ASTM-C165 (Standard Test Method for MeasuringCompressive Properties of Thermal Insulations1) standard for measuring the compressive strength of thermal insulation materials. The three properties obtained are shown in the following table:

[0083]

[0084] It can be seen from the data in the above table that the thermal insulation material prepared by the present invention exhibits excellent comprehensive performance by accurately selecting and optimizing the ratio of each component and improving the preparation process. The material can maintain structural integrity and is not easy to break during the battery expansion process; when the battery has thermal runaway, it will not only not increase the risk of fire, but also effectively block the spread of heat and prevent the thermal runaway battery from spreading heat to adjacent batteries. In summary, the thermal insulation material of the present invention meets the actual application requirements of lithium battery modules in terms of mechanical properties, flame retardant properties and thermal insulation properties, can be used for thermal protection of lithium battery modules, effectively inhibit the propagation of possible thermal runaway, and improve the safety and reliability of the battery system.

[0085] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0086] The parts not elaborated in detail in the description of the present invention belong to the known technology in the art. The above embodiments are provided only for the purpose of describing the present invention, and are not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims. Various equivalent substitutions and modifications made without departing from the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A super-pressure-resistant heat-insulating material, characterized in that: The ultra-pressure-resistant heat-insulating material comprises the following components in proportion by weight: 17.4 to 22.8 parts of a binder, 17.4 to 22.8 parts of hollow glass microspheres, 26.7 to 34.9 parts of an aerogel paste, and 15.1 to 34.9 parts of a mullite nanofiber dispersion.

2. The super-pressure-resistant heat-insulating material according to claim 1, characterized in that: The binder is one of epoxy resin, phenolic resin, water-based acrylic emulsion and water-based polyurethane.

3. The super pressure-resistant heat-insulating material according to claim 1, characterized in that: The hollow glass microspheres are hollow in structure and have an average particle size of 20-70 microns and a bulk density of 0.075-0.35 g / cm 3 .

4. The super pressure-resistant heat-insulating material according to claim 1, characterized in that: The aerogel paste comprises the following components in weight proportion: 65.8-84.6 parts of deionized water, 4.0-5.1 parts of auxiliary agent, 0.20-0.34 parts of cellulose, and 10.0-30.0 parts of aerogel powder.

5. The super pressure-resistant heat-insulating material according to claim 4, characterized in that: The auxiliary agent comprises the following components in weight proportion: 20-30 parts of dispersant, 20-30 parts of coupling agent, 20-30 parts of wetting agent, and 10-20 parts of defoaming agent.

6. The super-pressure-resistant heat-insulating material according to claim 5, characterized in that: The dispersant is polyacrylate ammonium salt anion 1124 dispersant and / or polycarboxylate sodium salt anion 5040 dispersant; And / or, the coupling agent is one or a mixture of several silane coupling agents; And / or, the wetting agent is one or a mixture of several of an alkylphenol nonionic surfactant complex, an anionic surfactant, and a nonionic low-foaming wetting agent; And / or, the defoaming agent is one or a mixture of several aqueous defoaming agents.

7. The super pressure-resistant heat-insulating material according to claim 4, characterized in that: The cellulose is one of methyl cellulose, ethyl cellulose, hydroxymethyl cellulose and hydroxyethyl cellulose, or a mixture of several of them.

8. The super pressure-resistant heat-insulating material according to claim 4, characterized in that: The aerogel powder is a nano-silicon dioxide aerogel powder, the porosity of the nano-silicon dioxide aerogel powder is greater than 90%, the average particle size of the nano-silicon dioxide aerogel powder is 5-50 microns, and the bulk density is 0.06-0.12 g / cm 3 .

9. The super pressure-resistant heat-insulating material according to claim 1, characterized in that: The mullite nanofiber dispersion comprises the following components in weight proportion: 5-10 parts of mullite nanofibers and 90-95 parts of deionized water.

10. The super pressure-resistant heat-insulating material according to claim 9, characterized in that: The mullite nanofiber is a fiber prepared by an electrostatic spinning process from a precursor solution; The precursor solution comprises the following components in weight proportion: 50.2-57.2 parts of deionized water, 12.0-13.7 parts of aluminum chloride hexahydrate, 25.4-29.0 parts of aluminum isopropoxide, 0-12.1 parts of tetraethyl orthosilicate, and 0.1-0.3 parts of polymer; wherein the polymer is one or a mixture of polyethylene oxide, polyvinyl alcohol, and polyethylene glycol.

11. The super-pressure-resistant heat-insulating material according to any one of claims 1 to 10, characterized in that: The super-pressure-resistant heat-insulating material also includes 3.4 parts to 4.6 parts of a flame retardant additive, wherein the flame retardant additive is one or a mixture of several of ammonium polyphosphate, aluminum hydroxide, and magnesium hydroxide.

12. The method for preparing the super-pressure-resistant heat-insulating material according to any one of claims 1 to 11, characterized in that: The steps include: S1. Mixing: adding the components in corresponding proportions to the binder according to the ratio, and mixing them evenly to obtain a mixture; S2. Shaping: shaping the mixture obtained in S1, and then putting it into a drying oven, and drying it at 60-100° C. for 10-14 hours to obtain the ultra-pressure-resistant thermal insulation material.

13. The method for preparing the super-pressure-resistant heat-insulating material according to claim 12, characterized in that: The aerogel paste is prepared by the following steps: S01: Add the auxiliary agent and cellulose to deionized water according to the ratio, stir evenly, then add the corresponding mass fraction of nano-silicon dioxide aerogel powder, and continue stirring until it becomes a paste, so as to obtain the aerogel paste.

14. The method for preparing the super-pressure-resistant heat-insulating material according to claim 12, characterized in that: The mullite nanofiber dispersion is prepared by the following steps: S02: Prepare a precursor solution: add aluminum chloride hexahydrate, aluminum isopropoxide, and tetraethyl orthosilicate into deionized water according to the ratio, stir for 10 to 14 hours, add an appropriate amount of polymer, and stir again for 2 to 4 hours to obtain a precursor solution; S03: preparing mullite nanofibers: electrospinning the precursor solution prepared in S02; After spinning, the fiber felt is collected, calcined, and cooled to obtain mullite nanofibers. S04: preparing fiber dispersion: cutting the calcined mullite nanofiber felt into small pieces, adding them into deionized water, and using a disperser to disperse them at a speed of 2000-4000 rpm for 4-8 minutes to obtain a fiber dispersion.

15. The method for preparing the super-pressure-resistant heat-insulating material according to claim 14, characterized in that: The calcination treatment is carried out at a temperature not lower than 1300° C. and for a period of 30 to 90 minutes.

16. The method for preparing the super-pressure-resistant heat-insulating material according to claim 14, characterized in that: The heating rate of the calcination treatment is 5-10 °C / min.

17. Application of the ultra-pressure-resistant heat-insulating material according to any one of claims 1 to 11 in a lithium battery module.

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