Preparation method of high-resilience aerogel composite material

Abstract

The invention discloses a preparation method of a high-resilience aerogel composite material. The preparation method comprises the following steps: S10, soaking; s20, compaction is carried out; s30, standing is carried out; s40, performing modification; s50, drying is carried out; the preparation method has the beneficial effects that the aerogel composite material with excellent rebound resilience and heat insulation performance is prepared through specific steps, the aerogel composite material with high rebound resilience can be obtained without additionally adding foam or reducing the solid content, and through optimal combination of the steps, the thermal insulation performance of the aerogel composite material is greatly improved. According to the present invention, the high resilience and the low heat conductivity coefficient of the aerogel composite material are achieved, and the high resilience aerogel composite material with different performance characteristics can be prepared by using different types of the fiber felts and the sol liquids and accurately controlling the pressure, the time and the chemical composition.

Description

Technical Field

[0001] The invention relates to a method for preparing a high-resilience aerogel composite material. Background Art

[0002] Aerogel has the characteristics of low density, high specific surface area, high porosity and pore volume due to its three-dimensional nanoporous structure. Therefore, aerogel is currently the solid material with the lowest thermal conductivity and the best thermal insulation performance. Due to its excellent performance of high efficiency thermal insulation under extreme environmental conditions, it is widely used in aerospace and military fields. In recent years, aerogel composite materials have also been widely used in the field of new energy vehicle manufacturing, especially in battery system design, as a key thermal insulation and fire barrier layer, thereby significantly improving the overall safety and reliability of new energy vehicle battery systems.

[0003] However, due to the overall brittleness of aerogel, the skeleton is prone to breakage under the action of external forces, so it is often compounded with fiber felt to obtain a composite product. During the assembly of the battery cell, the aerogel insulation pad needs to have a certain elastic force so that it can fill the gaps between the battery cells under different pressures. However, due to the high rigidity and weak resilience of aerogel composite products, it is often necessary to affix a layer of foam on the surface to improve its elasticity. Increasing the foam will reduce the use thickness of the aerogel composite material, thereby reducing its thermal insulation capacity. In view of this, the present invention proposes a method for preparing a high-resilience aerogel composite material to solve the above problems. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing a high-resilience aerogel composite material to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: A method for preparing a high-resilience aerogel composite material comprises the following steps: S10, soaking: The fiber felt is fully immersed in the sol liquid, and a pressing plate is placed on the fiber felt; S20, compaction: Applying pressure to the pressing plate so that the pressing plate moves downward to apply pressure to the fiber mat; S30, stand still: The fiber felt and sol-liquid composite material that has been pressurized in S20 is allowed to stand at room temperature to allow the sol-liquid to gel in the fiber felt; S40, modification: The fiber felt and sol-liquid composite in S30 are soaked with a hydrophobic modifier; S50, Drying: The fiber felt and sol-liquid composite material treated with a hydrophobic modifier in S40 are placed in a supercritical carbon dioxide drying device and dried under supercritical conditions to obtain a high-resilience aerogel composite material.

[0006] As an improvement of the above technical solution, in S10, the fiber felt is one of polyacrylonitrile fiber felt, glass fiber felt, and aluminum silicate fiber felt, and the number of the fiber felts is one or more stacked pieces.

[0007] As an improvement of the above technical solution, in S10, the sol liquid is one of silica sol, silica-alumina composite sol or alumina sol.

[0008] As an improvement of the above technical solution, in S40, the hydrophobic modifier is a mixed solution of dimethyldiethoxysilane, ammonium fluoride and ethanol.

[0009] As an improvement of the above technical solution, in S10, when the fiber felt is polyacrylonitrile fiber felt and the sol liquid is silica sol, the pressure applied to the pressing plate in S20 is 300 KPa until the fiber felt becomes 10% of the initial thickness and is then fixed.

[0010] As an improvement of the above technical solution, in S10, when the fiber felt is polyacrylonitrile fiber felt and the sol liquid is silica sol, in S30, the standing time at room temperature is 2 hours, and in S40, the mass ratio of dimethyldiethoxysilane, ammonium fluoride and ethanol in the hydrophobic modifier is 1:0.1:15, and the immersion time is 24 hours.

[0011] As an improvement of the above technical solution, in S10, when the fiber felt is glass fiber felt and the sol liquid is silicon-aluminum composite sol, the pressure applied to the pressing plate in S20 is 250 KPa until the fiber felt becomes 15% of the initial thickness and then is fixed.

[0012] As an improvement of the above technical solution, in S10, when the fiber felt is glass fiber felt and the sol liquid is a silica-alumina composite sol, in S30, the standing time at room temperature is 4 hours, and in S40, the mass ratio of dimethyldiethoxysilane, ammonium fluoride and ethanol in the hydrophobic modifier is 1:0.05:2, and the immersion time is 36 hours.

[0013] As an improvement of the above technical solution, in S10, when the fiber felt is aluminum silicate fiber felt and the sol liquid is alumina sol, the pressure applied to the pressing plate in S20 is 500Kpa until the fiber felt becomes 5% of the initial thickness and then fixed. As an improvement of the above technical solution, in S10, when the fiber felt is aluminum silicate fiber felt and the sol liquid is alumina sol, in S30, the standing time at room temperature is 6 hours, and in S40, the mass ratio of dimethyldiethoxysilane, ammonium fluoride and ethanol in the hydrophobic modifier is 1:0.15:10, and the immersion time is 20 hours.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The method prepares an aerogel composite material with excellent rebound performance and thermal insulation performance through specific steps, and provides an aerogel composite material that can obtain high rebound performance without adding additional foam or reducing the solid content. Through the optimized combination of these steps, the high rebound elasticity and low thermal conductivity of the aerogel composite material are achieved. Moreover, by using different types of fiber felts and sol liquids, and precisely controlling the pressure, time and chemical composition, the present invention can prepare high-rebound aerogel composite materials with different performance characteristics. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] Example: This embodiment provides a method for preparing a high-resilience aerogel composite material, comprising the following steps: S10, soaking: The fiber felt is fully immersed in the sol liquid, and a pressing plate is placed on the fiber felt; S20, compaction: Applying pressure to the pressing plate so that the pressing plate moves downward to apply pressure to the fiber mat; S30, stand still: The fiber felt and sol-liquid composite material that has been pressurized in S20 is allowed to stand at room temperature to allow the sol-liquid to gel in the fiber felt; S40, modification: The fiber felt and sol-liquid composite in S30 are soaked with a hydrophobic modifier; S50, Drying: The fiber felt and sol-liquid composite material treated with a hydrophobic modifier in S40 are placed in a supercritical carbon dioxide drying device and dried under supercritical conditions to obtain a high-resilience aerogel composite material.

[0017] In this embodiment, the method prepares an aerogel composite material with excellent rebound performance and thermal insulation performance through specific steps, and provides an aerogel composite material that can obtain high rebound performance without adding additional foam or reducing the solid content. Through the optimized combination of these steps, the high rebound and low thermal conductivity of the aerogel composite material are achieved. Moreover, by using different types of fiber felts and sol liquids, and precisely controlling the pressure, time and chemical composition, the present invention can prepare high-rebound aerogel composite materials with different performance characteristics.

[0018] Specifically, in S10, the fiber felt is one of polyacrylonitrile fiber felt, glass fiber felt, and aluminum silicate fiber felt, and the number of the fiber felts is one or a plurality of stacked pieces.

[0019] Specifically, in S10, the sol liquid is one of silica sol, silica-alumina composite sol or alumina sol.

[0020] Specifically, in S40, the hydrophobic modifier is a mixed solution of dimethyldiethoxysilane, ammonium fluoride and ethanol.

[0021] Specifically, in S10, when the fiber felt is polyacrylonitrile fiber felt and the sol liquid is silica sol, the pressure applied to the pressing plate in S20 is 300 KPa until the fiber felt becomes 10% of the initial thickness and is then fixed.

[0022] Specifically, in S10, when the fiber felt is polyacrylonitrile fiber felt and the sol liquid is silica sol, in S30, the standing time at room temperature is 2 hours, and in S40, the mass ratio of dimethyldiethoxysilane, ammonium fluoride and ethanol in the hydrophobic modifier is 1:0.1:15, and the immersion time is 24 hours.

[0023] In this embodiment, by selecting the above-mentioned fiber felt and sol liquid and processing them under specified parameters, a high-rebound polyacrylonitrile fiber-based silica aerogel composite material can be obtained, and the thermal conductivity of the high-rebound polyacrylonitrile fiber-based silica aerogel composite material at 25°C is 0.019W / (m∙K), and the rebound rate is 60% at 6.2MPa when the compression strain is 65%.

[0024] Specifically, in S10, when the fiber felt is a glass fiber felt and the sol liquid is a silicon-aluminum composite sol, the pressure applied to the pressing plate in S20 is 250 KPa until the fiber felt becomes 15% of the initial thickness and is then fixed.

[0025] Specifically, in S10, when the fiber felt is glass fiber felt and the sol liquid is a silica-alumina composite sol, in S30, the standing time at room temperature is 4 hours, and in S40, the mass ratio of dimethyldiethoxysilane, ammonium fluoride and ethanol in the hydrophobic modifier is 1:0.05:2, and the immersion time is 36 hours.

[0026] In this embodiment, by selecting the above-mentioned fiber felt and sol liquid and processing them under specified parameters, a high-rebound glass fiber-based silicon-aluminum composite aerogel composite material can be obtained, and the thermal conductivity of the high-rebound glass fiber-based silicon-aluminum composite aerogel composite material at 25°C is 0.022W / (m∙K), and the rebound rate is 63% at 7.0MPa when the compression strain is 65%.

[0027] Specifically, in S10, when the fiber felt is aluminum silicate fiber felt and the sol liquid is aluminum oxide sol, the pressure applied to the pressing plate in S20 is 500 KPa until the fiber felt becomes 5% of the initial thickness and is then fixed.

[0028] Specifically, in S10, when the fiber felt is aluminum silicate fiber felt and the sol liquid is alumina sol, in S30, the standing time at room temperature is 6 hours, and in S40, the mass ratio of dimethyldiethoxysilane, ammonium fluoride and ethanol in the hydrophobic modifier is 1:0.15:10, and the immersion time is 20 hours.

[0029] In this embodiment, by selecting the above-mentioned fiber felt and sol liquid and processing them under specified parameters, a high-rebound aluminum silicate fiber-based alumina aerogel composite material can be obtained, and the thermal conductivity of the high-rebound aluminum silicate fiber-based alumina aerogel composite material at 25°C is 0.018W / (m∙K), and the rebound rate is 63% at 7.0MPa when the compression strain is 65%.

[0030] The above-mentioned preparation method can effectively solve the problem in the prior art that foam is needed or the solid content is reduced to improve the elasticity of the aerogel composite material. The aerogel composite material prepared by the present invention has good rebound performance and good thermal insulation performance, and is suitable for high-temperature insulation of thermal runaway between battery cells and other fields.

[0031] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a high resilience aerogel composite material, characterized in that: The following steps are involved: S10, soaking: The fiber felt is fully immersed in the sol liquid, and a pressing plate is placed on the fiber felt; S20, compaction: Applying pressure to the pressing plate so that the pressing plate moves downward to apply pressure to the fiber mat; S30, stand still: The fiber felt and sol-liquid composite material that has been pressurized in S20 is allowed to stand at room temperature to allow the sol-liquid to gel in the fiber felt; S40, modification: The fiber felt and sol-liquid composite in S30 are soaked with a hydrophobic modifier; S50, Drying: The fiber felt and sol-liquid composite material treated with a hydrophobic modifier in S40 are placed in a supercritical carbon dioxide drying device and dried under supercritical conditions to obtain a high-resilience aerogel composite material.

2. The method for preparing a high resilience aerogel composite material according to claim 1, characterized in that: In S10, the fiber felt is one of polyacrylonitrile fiber felt, glass fiber felt, and aluminum silicate fiber felt, and the number of the fiber felts is one or a plurality of stacked pieces.

3. The method for preparing a high resilience aerogel composite material according to claim 2, characterized in that: In the step S10, the sol liquid is one of silica sol, silica-alumina composite sol or alumina sol.

4. The method for preparing a high resilience aerogel composite material according to claim 3, characterized in that: In the step S40, the hydrophobic modifier is a mixed solution of dimethyldiethoxysilane, ammonium fluoride and ethanol.

5. The method for preparing a high resilience aerogel composite material according to claim 4, characterized in that: In the S10, when the fiber felt is polyacrylonitrile fiber felt and the sol liquid is silica sol, the pressure applied to the pressing plate in S20 is 300 KPa until the fiber felt becomes 10% of the initial thickness and then is fixed.

6. The method for preparing a high resilience aerogel composite material according to claim 5, characterized in that: In the S10, when the fiber felt is polyacrylonitrile fiber felt and the sol liquid is silica sol, in S30, the standing time at room temperature is 2 hours, and in S40, the mass ratio of dimethyldiethoxysilane, ammonium fluoride and ethanol in the hydrophobic modifier is 1:0.1:15, and the immersion time is 24 hours.

7. The method for preparing a high resilience aerogel composite material according to claim 4, characterized in that: In the S10, when the fiber felt is a glass fiber felt and the sol liquid is a silicon-aluminum composite sol, the pressure applied to the pressing plate in S20 is 250 KPa until the fiber felt becomes 15% of the initial thickness and is then fixed.

8. The method for preparing a high resilience aerogel composite material according to claim 7, characterized in that: In the S10, when the fiber felt is glass fiber felt and the sol liquid is a silica-alumina composite sol, in S30, the standing time at room temperature is 4 hours, and in S40, the mass ratio of dimethyldiethoxysilane, ammonium fluoride and ethanol in the hydrophobic modifier is 1:0.05:2, and the immersion time is 36 hours.

9. The method for preparing a high resilience aerogel composite material according to claim 4, characterized in that: In the S10, when the fiber felt is aluminum silicate fiber felt and the sol liquid is aluminum oxide sol, the pressure applied to the pressing plate in S20 is 500 KPa until the fiber felt becomes 5% of the initial thickness and then is fixed.

10. The method for preparing a high resilience aerogel composite material according to claim 9, characterized in that: In the S10, when the fiber felt is aluminum silicate fiber felt and the sol liquid is alumina sol, in S30, the standing time at room temperature is 6 hours, and in S40, the mass ratio of dimethyldiethoxysilane, ammonium fluoride and ethanol in the hydrophobic modifier is 1:0.15:10, and the immersion time is 20 hours.