阅读说明：本技术 一种抗缓冲二氧化硅气凝胶隔热片的制备方法 (Preparation method of anti-buffering silicon dioxide aerogel heat insulation sheet ) 是由 董会娜 张继承 张东生 何凤霞 王琰 陈帅 张蔓蔓 于 2021-08-20 设计创作，主要内容包括：本发明属于隔热保温材料领域,公开一种抗缓冲二氧化硅气凝胶隔热片的制备方法：本发明在纤维毡阶段根据实际应用需求对毡体进行裁切并与抗缓冲部件硅橡胶框组合,然后按照溶胶-凝胶、干燥及封装过程完成抗缓冲气凝胶隔热片的制备过程,避免了传统制备工艺中针对气凝胶卷毡在裁切以及在功能构件的封装过程中造成大量的气凝胶粉脱落现象,并一定程度影响气凝胶隔热构件的隔热性能降低、分布不均匀等情况。本发明对干燥得到的抗缓冲气凝胶隔热片直接进行封装处理,有效的解决了目前气凝胶片制备过程中存在的掉粉问题,并实现了高效的封装效率。(The invention belongs to the field of heat insulation materials, and discloses a preparation method of an anti-buffering silicon dioxide aerogel heat insulation sheet, which comprises the following steps: according to the invention, the felt body is cut according to the actual application requirement at the fibrofelt stage and combined with the silicon rubber frame of the anti-buffering component, and then the preparation process of the anti-buffering aerogel heat insulation sheet is completed according to the sol-gel, drying and packaging processes, so that the phenomena of a large amount of aerogel powder falling off caused in the cutting process of the aerogel roll felt and the packaging process of the functional component in the traditional preparation process are avoided, and the conditions of heat insulation performance reduction, uneven distribution and the like of the aerogel heat insulation component are influenced to a certain extent. According to the invention, the anti-buffering aerogel heat insulation sheet obtained by drying is directly packaged, so that the problem of powder falling in the existing aerogel sheet preparation process is effectively solved, and the high-efficiency packaging efficiency is realized.)

1. The preparation method of the anti-buffering silicon dioxide aerogel heat insulation sheet is characterized by comprising the following steps:

(1) preparation of fiber sheet:

(a) cutting the silicon rubber coil stock by adopting a reverse-type cutting die to obtain a reverse-type silicon rubber frame with the required size; (b) putting the fibrofelt sheet with the corresponding size into a silicon rubber frame to obtain a required fiber sheet;

(2) preparing a silicon dioxide wet gel sheet, namely dipping the fiber sheet obtained in the step (1) in silicon dioxide sol catalyzed by a gelling catalyst before gelling to prepare the silicon dioxide wet gel sheet or dipping the fiber sheet in the silicon dioxide sol and then catalyzing gelling by the gelling catalyst to prepare the silicon dioxide wet gel sheet;

(3) and (3) drying treatment: drying the silica wet gel sheet obtained in the step (2) to obtain a silica aerogel sheet;

(4) packaging treatment: and (4) covering the upper surface and the lower surface of the silicon dioxide aerogel sheet obtained in the step (3) with a packaging material, packaging and forming, and then trimming the product to obtain the anti-buffering silicon dioxide aerogel heat insulation sheet.

2. The method for preparing an anti-buffering silica aerogel thermal insulation sheet according to claim 1, wherein the method comprises the following steps: in the step (1), the fibers in the fiber sheet are one or a combination of two or more of the following fiber materials: quartz fibers, glass fibers, high silica fibers, carbon fibers, pre-oxidized fiber, mullite fibers, basalt fibers, silicon carbide fibers, silicon nitride fibers, alumina fibers, and boron nitride fibers.

3. The method for preparing an anti-buffering silica aerogel thermal insulation sheet according to claim 1, wherein the method comprises the following steps: in the step (2), the silica sol is obtained by mixing a silicon source, ethanol and water in a molar ratio of 1 to (2-60) to (1-30); the silicon source is one or more than two of ethyl orthosilicate, methyl orthosilicate, butyl orthosilicate, isopropyl orthosilicate or alkyl alkoxy silane; the alkyl alkoxy silane comprises one or more than two of methyl trimethoxy silane, dimethyl dimethoxy silane, methyl triethoxy silane, dimethyl diethoxy silane, vinyl triethoxy silane, propyl trimethoxy silane or propyl triethoxy silane; the gelling catalyst is one or a combination of two of alkaline catalysts such as sodium hydroxide, potassium hydroxide, ammonia water and ammonium fluoride aqueous solution; the gelling catalyst adjusts the pH of the silica sol to 6-8.

4. The method for preparing an anti-buffering silica aerogel thermal insulation sheet according to claim 3, wherein the method comprises the following steps: also comprises adding an acid catalyst into the silica sol, and adjusting the pH of the solution to 2-6.

5. The method for preparing an anti-buffering silica aerogel thermal insulation sheet according to claim 1, wherein the method comprises the following steps: and (2) further comprising a gel aging process of the silicon dioxide wet gel sheet, specifically, the silicon dioxide wet gel sheet is aged for 8-24h at room temperature or under the condition of heating to 30-60 ℃.

6. The method of preparing an anti-buffering silica aerogel thermal insulation sheet according to claim 5, wherein: and (3) before drying the silica wet gel sheet, a solvent replacement process is also included, specifically, the silica wet gel sheet is placed in absolute ethyl alcohol for solvent replacement.

7. The method of preparing an anti-buffering silica aerogel thermal insulation sheet according to claim 6, wherein: the method also comprises a hydrophobization treatment process of the silica wet gel sheet before the solvent replacement process, and specifically comprises the steps of placing the silica wet gel sheet in an anhydrous ethanol solution containing 0.2-10% of hydrophobization agent in volume fraction, and standing for 1-24h at room temperature.

8. The method for preparing an anti-buffering silica aerogel thermal insulation sheet according to claim 1, wherein the method comprises the following steps: and (4) the packaging material is fiber cloth or a high polymer packaging film.

9. An anti-buffering silica aerogel insulation sheet prepared by the method of any of claims 1 to 8.

10. The anti-buffering silica aerogel heat insulation sheet prepared by the method of any one of claims 1 to 8 is applied to the field of batteries for new energy automobiles.

Technical Field

The invention belongs to the field of heat insulation materials, and particularly relates to a preparation method of an anti-buffering silicon dioxide aerogel heat insulation sheet.

Background

At present, developing new energy, improving the utilization rate of the existing energy and saving energy have attracted great attention from various countries. China is an energy-poor country, so that reasonable utilization of energy and energy conservation have important significance on sustainable development of China's society. The development of environment-friendly heat insulation materials by adopting new technology and new process is one of the most effective and economic measures for saving energy.

SiO₂Aerogel is a new super heat-insulating material, has extremely low heat conductivity coefficient which is far lower than that of static air at normal temperature by 0.25W/m.K, has incomparable heat-insulating and heat-preserving effects compared with other materials, has low density, is waterproof, flame-retardant, green and environment-friendly, is corrosion-resistant, is not easy to age, has long service life, and is called as the super heat-insulating material. At present, the method is mainly used for industrial pipelines, industrial furnace bodies, escape capsules and transportationHeat preservation and insulation in the fields of transmission, household appliances, glass and the like.

At present, for SiO₂The excellent heat-proof quality of aerogel, it is in the new forms of energy as the functional component, industry, extensive application has been realized in fields such as building, current thermal-insulated component all adopts the preparation earlier to obtain the aerogel book felt, later cut into the thermal-insulated sheet of aerogel of needs size according to the application demand, and then cushion according to the requirement of functional component, heat conduction, the setting on fire-retardant layer, at the in-process that the aerogel book felt cut, the ubiquitous felt body drops the condition of aerogel powder, cause more serious dust pollution, the powder condition that falls has not only brought the inconvenience for the construction, threat has been brought for constructor health, also can reduce the performance of aerogel felt itself simultaneously. Meanwhile, the aerogel roll felt is often because the poor very easy fold and the irregular tear that causes aerogel felt edge of cutting process control in the cutting process, and then takes off a large amount of aerogel powder, and then reduces the heat-proof quality of felt body. Therefore, on the premise of ensuring good heat insulation performance of the aerogel felt, it is necessary to develop a process for reducing powder falling of the aerogel felt to ensure the health of production and use personnel and meet the requirements of various fields in the market.

Based on the powder falling phenomenon of the existing aerogel felt in cutting and the influence on the heat insulation performance, the process for preparing the aerogel component with the required function is characterized in that the fiber felt is cut according to the application requirement before sol is not soaked according to the specific application requirement, and meanwhile, the fiber felt is assembled with the required functional component, so that the aerogel component with the required function is prepared.

Disclosure of Invention

Aiming at the problems of powder falling phenomenon and reduction of heat insulation performance caused by a cutting process and a process of compounding with a functional structure in the process of applying and functional components of the existing aerogel felt, the invention provides a preparation method of an anti-buffering silica aerogel heat insulation sheet, aiming at the problems existing in the application of the existing aerogel as the functional component in the field of new energy vehicles.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the preparation method of the anti-buffering silicon dioxide aerogel heat insulation sheet is characterized by comprising the following steps:

(1) preparation of fiber sheet:

(a) cutting the silicon rubber coil stock by adopting a reverse-type cutting die to obtain a reverse-type silicon rubber frame with the required size; (b) and putting the fiber felt sheet with the corresponding size into a silicone rubber frame to obtain the required fiber sheet.

(2) And (2) preparing the silica wet gel sheet, namely dipping the silica sol catalyzed by the gelling catalyst into the fiber sheet obtained in the step (1) before gelling to prepare the silica wet gel sheet or dipping the fiber sheet into the silica sol and then catalyzing gelling by the gelling catalyst to prepare the silica wet gel sheet.

(3) And (3) drying treatment: drying the silica wet gel sheet obtained in the step (2) to obtain a silica aerogel sheet;

(4) packaging treatment: and (4) covering the upper surface and the lower surface of the silicon dioxide aerogel sheet obtained in the step (3) with a packaging material, performing hot press molding on the silicon dioxide aerogel sheet on a hot press, and then performing trimming treatment on the product to obtain the required anti-buffering silicon dioxide aerogel heat insulation sheet.

Preferably, the fibers in the fibrous sheet are one or a combination of two or more of the following group of fibrous materials: quartz fibers, glass fibers, high silica fibers, carbon fibers, pre-oxidized fibers, mullite fibers, basalt fibers, silicon carbide fibers, silicon nitride fibers, alumina fibers, or boron nitride fibers.

Preferably, the fibers in the fiber sheet are further preferably one or a combination of two or more of glass fibers, high silica fibers, and pre-oxidized fiber.

Preferably, in the step (1), the thickness of the silicone rubber frame is 4-8mm, the thickness of the fiber felt sheet is 2-6mm, and the thickness of the fiber felt sheet is selected according to the thickness requirement required by the finally prepared aerogel heat insulation sheet and the variation tolerance of the thickness after the composite aerogel is considered.

Preferably, in the step (2), the silica sol is obtained by mixing a silicon source, ethanol and water in a molar ratio of 1 to (2-60) to (1-30); the silicon source is one or more than two of ethyl orthosilicate, methyl orthosilicate, butyl orthosilicate, isopropyl orthosilicate or alkyl alkoxy silane; the alkyl alkoxy silane comprises one or more than two of methyl trimethoxy silane, dimethyl dimethoxy silane, methyl triethoxy silane, dimethyl diethoxy silane, vinyl triethoxy silane, propyl trimethoxy silane or propyl triethoxy silane; the gelling catalyst is one or a combination of two of alkaline catalysts such as sodium hydroxide, potassium hydroxide, ammonia water and ammonium fluoride aqueous solution; the gelling catalyst adjusts the pH of the silica sol to 6-8.

Preferably, the method also comprises the steps of adding an acid catalyst into the silica sol, and adjusting the pH of the solution to 2-6; the acidic catalyst is one or the combination of more than two of sulfuric acid, hydrochloric acid, hydrofluoric acid, oxalic acid, acetic acid or benzenesulfonic acid.

Preferably, the step (2) further comprises a gel aging process of the silica wet gel sheet, specifically, the silica wet gel sheet is aged for 8-24 hours at room temperature or at 30-60 ℃.

Preferably, a solvent replacement process is further included before the silica wet gel sheet is dried in the step (3), specifically, the silica wet gel sheet is placed in absolute ethyl alcohol for solvent replacement, the number of times of replacement is 1-4, and the time of each replacement is 2-12 hours.

Preferably, the method also comprises a hydrophobization treatment process of the silica wet gel sheet before the sol replacement, specifically, the silica wet gel sheet is placed in an anhydrous ethanol solution containing 0.2-10% of hydrophobization agent by volume fraction and is kept standing for 1-24h at room temperature.

Preferably, the drying treatment in step (3) is one of supercritical drying, freeze drying and atmospheric drying.

Preferably, the packaging material in the step (4) is fiber cloth or a polymer packaging film.

Preferably, the fiber cloth is the fiber cloth with the surface coated with an adhesive, the fiber cloth with the surface adhered with a double-sided adhesive tape or the fiber cloth with the surface covered with a hot melt adhesive net film; the surface of the fiber cloth is coated with an adhesive, and is adhered with a double-sided adhesive or the surface of one side of the fiber cloth is covered with the upper surface and the lower surface of the silicon dioxide aerogel sheet. When the fiber cloth with the surface coated with the adhesive or the fiber cloth with the surface pasted with the double-sided adhesive is adopted for packaging, the fiber cloth is directly pasted on the upper surface and the lower surface of the silicon dioxide aerogel sheet, and the adhesive is one of epoxy resin glue, polyurethane glue, optical epoxy glue, saturated polyester glue and polyvinyl acetal glue. When the fiber cloth with the surface covered by the hot melt adhesive net film is used for packaging, the packaging is finished on a hot press, the hot pressing temperature is 140-.

Preferably, the fiber cloth is one of glass fiber cloth, high silica fiber cloth, carbon fiber cloth, mullite fiber cloth and basalt fiber cloth.

Preferably, the polymer packaging film is one of a polyester film, a polyimide film, a polyvinyl chloride film, a polycarbonate film, a polyethylene film and a polyphenylene sulfide film. The encapsulation process of the polymer encapsulation film is completed on a hot press, the hot pressing temperature is 50-75 ℃, the pressure is 10-20Mpa, and the time is 10-30 s.

Preferably, a surface treatment process is further included before the packaging treatment in step (4), specifically, the silica aerogel sheet obtained in step (3) is subjected to blowing to remove floating powder on the surface.

The anti-buffering silicon dioxide aerogel heat insulation sheet prepared by the method.

The anti-buffering silica aerogel heat insulation sheet obtained by the method is applied to the field of batteries for new energy automobiles.

Has the advantages that:

the invention provides a preparation method of an anti-buffering silicon dioxide aerogel heat insulation sheet, which is different from the traditional preparation process, the felt body is cut according to the actual application requirement at the fiber felt stage, the required fiber sheet is obtained by combining the cut felt body with an auxiliary functional component anti-buffer layer, and the preparation of the anti-buffering aerogel heat insulation sheet is further completed according to the sol-gel, drying and packaging processes, so that the phenomena that a large amount of aerogel powder falls off in the processes of cutting an aerogel roll felt, packaging a functional component and the like in the traditional preparation process, and the heat insulation performance of an aerogel heat insulation component is reduced and the distribution is uneven and the like to a certain extent are avoided. The invention directly packages the dried aerogel heat insulation sheet, effectively solves the problem of powder falling of the aerogel heat insulation sheet in the preparation process at present, and realizes high-efficiency packaging efficiency.

The anti-buffering silicon dioxide aerogel heat insulation sheet is mainly used for heat insulation between a battery cell and an electric core in the field of new energy batteries, the silicon rubber frame is arranged around the heat insulation layer, the compression resilience of the silicon rubber frame is good, the electric core is heated in the using process to cause a certain expansion effect, a bulge condition occurs, and the silicon rubber frame can bear a certain pressure to play a buffering role. Simultaneously, after the electric core swell condition disappears, through the structural dimension design of silica gel frame and insulating layer, can play the effect of location to the aerogel piece, fix it fine between electric core and electric core, prevent droing of aerogel piece.

The invention provides a preparation method of an anti-buffering silicon dioxide aerogel heat insulation sheet, which well solves the problem of aerogel powder falling commonly existing in the industry at present, meets the anti-buffering application requirement in the field of new energy application, and can also realize the construction of functional components in the fiber felt body stage aiming at other functional components such as flame retardance, heat conduction, sound insulation, high strength and the like, so as to prepare the required aerogel heat insulation component.

Detailed Description

The present invention will be further described with reference to the following specific examples. It should be understood that the following examples are illustrative only and are not intended to limit the scope of the present invention.

Example 1

The preparation method of the anti-buffering silicon dioxide aerogel heat insulation sheet is characterized by comprising the following steps:

(1) preparation of fiber sheet:

(a) cutting the silicon rubber coil material by adopting a reverse-type cutting die to obtain a reverse-type silicon rubber frame with the required size; (b) putting the pre-oxidized fiber felt sheet with the corresponding size into a silicon rubber frame to obtain the required pre-oxidized fiber sheet, wherein the thickness of the silicon rubber frame is 4, and the thickness of the fiber sheet is 3.5 mm;

(2) taking a silicon source, ethanol and water, uniformly mixing, adding a gelling catalyst to enable the pH of the solution to be 7, uniformly stirring to obtain catalyzed silica sol, and dipping the pre-oxidized fiber sheet obtained in the step 1 and gelling the pre-oxidized fiber sheet in the catalyzed silica sol to obtain a silica wet gel sheet;

(3) aging the gel: aging the silicon dioxide wet gel sheet at room temperature or 60 ℃ for 12 h;

(4) gel hydrophobization treatment: placing the aged fiber reinforced silica wet gel into an absolute ethyl alcohol solution containing a hydrophobizing agent with the volume fraction of 8%, and standing for 6 hours at room temperature;

(5) solvent replacement: placing the silicon dioxide wet gel sheet subjected to gel aging treatment in absolute ethyl alcohol for solvent replacement for 3 times, wherein the time of each time is 12 hours;

(6) and (3) drying treatment: carrying out supercritical drying treatment on the silica wet gel sheet subjected to solvent replacement to obtain a silica aerogel sheet;

(7) packaging treatment: and (4) covering polyester packaging films on the upper surface and the lower surface of the silicon dioxide aerogel sheet obtained in the step (6), carrying out hot press molding on the silicon dioxide aerogel sheet at the temperature of 65 ℃, the pressure of 12Mpa and the time of 15s on a hot press, and then trimming the product to obtain the required anti-buffering silicon dioxide aerogel heat insulation sheet.

Wherein, in the step (2), the molar ratio of the silicon source to the ethanol to the water is = 1: 6: 2, and the silicon source is tetraethoxysilane.

The gel catalyst in the step (2) is a combination of ammonia water and ammonium fluoride, and the molar ratio of the ammonia water to the ammonium fluoride is (0.002-0.01): (0.005-0.015).

In the step (4), the hydrophobizing agent is hexamethyldisiloxane.

The anti-buffering silicon dioxide aerogel heat insulation sheet is obtained through the steps. The anti-buffering silicon dioxide aerogel heat insulation sheet is used in the field of batteries for new energy automobiles.

The thermal conductivity coefficient of the anti-buffer heat-insulation sheet obtained in the embodiment is 0.019 w/(m.DEG C).

Example 2

The preparation method of the anti-buffering silicon dioxide aerogel heat insulation sheet is characterized by comprising the following steps:

(1) preparation of fiber sheet:

(a) cutting the silicon rubber coil material by adopting a reverse-type cutting die to obtain a reverse-type silicon rubber frame with the required size; (b) and putting the glass fiber mat sheet with the corresponding size into a silicon rubber frame to obtain the required glass fiber sheet, wherein the thickness of the silicon rubber frame is 5, and the thickness of the fiber sheet is 4.3 mm.

(2) Taking a silicon source, ethanol and water, uniformly mixing, uniformly stirring to obtain silicon dioxide sol, dipping the glass fiber sheet obtained in the step 1 into the silicon dioxide sol, and then adding a gelling catalyst to gel to obtain a silicon dioxide wet gel sheet;

(3) aging the gel: aging the silicon dioxide wet gel sheet at room temperature or 50 ℃ for 16 h;

(4) gel hydrophobization treatment: placing the aged fiber reinforced silica wet gel into an absolute ethyl alcohol solution containing a hydrophobizing agent with the volume fraction of 2%, and standing for 8 hours at room temperature;

(5) solvent replacement: placing the silicon dioxide wet gel sheet subjected to gel aging treatment in absolute ethyl alcohol for solvent replacement for 3 times, wherein the time of each time is 10 hours;

(6) and (3) drying treatment: carrying out supercritical drying treatment on the silica wet gel sheet subjected to solvent replacement to obtain a silica aerogel sheet;

(7) packaging treatment: and (4) covering the upper surface and the lower surface of the silicon dioxide aerogel sheet obtained in the step (6) with glass fiber cloth coated with epoxy resin glue, wherein one surface of the glass fiber cloth coated with the adhesive is directly attached to the upper surface and the lower surface of the silicon dioxide aerogel sheet, and then trimming the product to obtain the required anti-buffering silicon dioxide aerogel heat insulation sheet.

Wherein, in the step (2), the molar ratio of silicon source to ethanol to water is = 1: 30: 8, and the silicon source is dimethyldimethoxysilane.

In the step (2), the gel catalyst is ammonia water, and the PH of the sol is adjusted to 6.

In the step (4), the hydrophobizing agent is hexamethyldisiloxane.

When the packaging material is fiber cloth coated with an adhesive, the temperature in the hot press molding process is determined according to the curing temperature of the adhesive used in the prior art.

The anti-buffering silicon dioxide aerogel heat insulation sheet is obtained through the steps. The anti-buffering silicon dioxide aerogel heat insulation sheet is used in the field of batteries for new energy automobiles.

The thermal conductivity of the anti-buffer heat-insulation sheet obtained in the embodiment is 0.021w/(m DEG C).

Example 3

The preparation method of the anti-buffering silicon dioxide aerogel heat insulation sheet is characterized by comprising the following steps:

(1) preparation of fiber sheet:

(a) cutting the silicon rubber coil material by adopting a reverse-type cutting die to obtain a reverse-type silicon rubber frame with the required size; (b) and (3) putting the aluminum silicate fiber felt sheet with the corresponding size into a silicon rubber frame to obtain the required aluminum silicate fiber sheet, wherein the thickness of the silicon rubber frame is 6, and the thickness of the fiber sheet is 5 mm.

(2) Taking a silicon source, ethanol and water, uniformly mixing, sequentially adding a gelling catalyst to enable the pH of the solution to be 6.5, uniformly stirring to obtain catalyzed silica sol, and dipping the aluminum silicate fiber sheet obtained in the step 1 and gelling the aluminum silicate fiber sheet in the catalyzed silica sol to obtain a silica wet gel sheet;

(3) aging the gel: aging the silicon dioxide wet gel sheet at room temperature or 40 ℃ for 18 h;

(4) gel hydrophobization treatment: placing the aged fiber reinforced silica wet gel into an absolute ethyl alcohol solution containing a hydrophobizing agent with the volume fraction of 8%, and standing for 10 hours at room temperature;

(5) solvent replacement: placing the silicon dioxide wet gel sheet subjected to gel aging treatment in absolute ethyl alcohol for solvent replacement for 4 times, wherein each time is 8 hours;

(6) and (3) drying treatment: carrying out supercritical drying treatment on the silica wet gel sheet subjected to solvent replacement to obtain a silica aerogel sheet;

(7) packaging treatment: covering the upper surface and the lower surface of the silicon dioxide aerogel sheet obtained in the step (6) with high silica fiber cloth, covering the surface of the high silica fiber cloth with a hot melt adhesive net film, attaching one surface of the high silica fiber cloth, which is covered with the hot melt adhesive net film, to the upper surface and the lower surface of the silicon dioxide aerogel sheet, then performing hot press molding on the silicon dioxide aerogel sheet at the temperature of 150 ℃ for 30s, and then performing trimming treatment on the product to obtain the required anti-buffering silicon dioxide aerogel heat insulation sheet.

Wherein, in the step (2), the molar ratio of the silicon source to the ethanol to the water is = 1: 40: 10, and the silicon source is methyltrimethoxysilane.

In the step (2), the gel catalyst is ammonium fluoride.

In the step (4), the hydrophobizing agent is trimethylchlorosilane.

The anti-buffering silicon dioxide aerogel heat insulation sheet is obtained through the steps. The anti-buffering silicon dioxide aerogel heat insulation sheet is used in the field of batteries for new energy automobiles.

The thermal conductivity of the anti-buffer heat-insulation sheet obtained in the embodiment is 0.023w/(m DEG C).

Example 4

The preparation process includes adding acid catalyst hydrochloric acid to silica sol to adjust the pH of the solution to 4 before adding the gelling catalyst in step (2), which is the same as the procedure in example 1.

The anti-buffering silica aerogel thermal insulation sheet prepared by this example. The anti-buffering silicon dioxide aerogel heat insulation sheet is used in the field of batteries for new energy automobiles.

The thermal conductivity of the anti-buffer heat-insulation sheet obtained in the embodiment is 0.02w/(m DEG C).

Example 5

In the preparation process, a solvent replacement process was not included, which was the same as in example 1.

The anti-buffering silica aerogel thermal insulation sheet prepared by this example. The anti-buffering silicon dioxide aerogel heat insulation sheet is used in the field of batteries for new energy automobiles.

The thermal conductivity of the anti-buffer heat-insulation sheet obtained in the embodiment is 0.023w/(m DEG C).

Example 6

In the preparation process, the gel hydrophobization treatment was not included, and the procedure was the same as in example 2.

The anti-buffering silica aerogel thermal insulation sheet prepared by this example. The anti-buffering silicon dioxide aerogel heat insulation sheet is used in the field of batteries for new energy automobiles.

The thermal conductivity of the anti-buffer heat-insulation sheet obtained in the embodiment is 0.021w/(m DEG C).

Example 7

In the preparation process, the gel aging treatment, the gel hydrophobization treatment and the solvent replacement process described in the steps (3) to (5) were not included, and the same procedure as in example 2 was conducted.

The anti-buffering silica aerogel thermal insulation sheet prepared by this example. The anti-buffering silicon dioxide aerogel heat insulation sheet is used in the field of batteries for new energy automobiles.

The thermal conductivity of the anti-buffer heat-insulation sheet obtained in the embodiment is 0.023w/(m DEG C).

Example 8

In the preparation process, the gel hydrophobization treatment and the solvent replacement process described in the steps (4) to (5) are not included, and the steps are the same as those of example 2.

The anti-buffering silica aerogel thermal insulation sheet prepared by this example. The anti-buffering silicon dioxide aerogel heat insulation sheet is used in the field of batteries for new energy automobiles.

The thermal conductivity of the anti-buffer heat-insulation sheet obtained in the embodiment is 0.022w/(m DEG C).

Example 9

In the preparation process, before the packaging treatment in the step (7), a surface treatment is further included, specifically, the silica aerogel sheet is subjected to purging to remove floating powder on the surface, which is the same as the step in the example 1.

The anti-buffering silica aerogel thermal insulation sheet prepared by this example. The anti-buffering silicon dioxide aerogel heat insulation sheet is used in the field of batteries for new energy automobiles.

The thermal conductivity of the anti-buffer heat-insulation sheet obtained in the embodiment is 0.02w/(m DEG C).