Preparation method for hydrophobic aerogel, composite material and preparation method therefor, and battery device

Abstract

Disclosed in the present application are a preparation method for a hydrophobic aerogel, a composite material and a preparation method therefor, and a battery device. The preparation method for the hydrophobic aerogel comprises: mixing a precursor hydrolysate, a catalyst and a hydrophobic agent to form a mixed prepolymer solution, and reacting the mixed prepolymer solution to obtain a prepolymer wet gel; and drying the prepolymer wet gel. In this way, by directly using the precursor hydrolysate, a precursor hydrolysis step is omitted. During the reaction with the hydrophobic agent, the hydrophobic agent no longer participates in the hydrolysis of the precursor, and participates more in the modification reaction, thereby reducing the consumption of the hydrophobic agent. In addition, in the present application, no separate operation step or device is required for hydrophobic modification, and therefore the preparation method for the hydrophobic aerogel provided in the present application is simpler in operation, more environmentally friendly, and more cost-saving.

Description

Preparation methods of hydrophobic aerogels and composite materials and preparation methods, battery devices

[0001] Cross-referencing of related applications

[0002] This application claims priority to Chinese patent application No. 202411839009.1, filed on December 13, 2024, the entire contents of which are incorporated herein by reference. [Technical Field]

[0003] This application relates to the field of hydrophobic aerogels, and in particular to a method for preparing hydrophobic aerogels, composite materials and preparation methods, and battery devices. [Background Technology]

[0004] Hydrophobic aerogels are a special type of hydrogel containing a certain amount of hydrophobic segments or groups. These groups can be side groups on the gel network or side groups of chain-like polymers embedded within the gel. Due to the interactions of their internal hydrophobic groups, hydrophobic aerogels exhibit unique environmental stimulus-response characteristics, such as responses to changes in pH, temperature, and solvent, as well as differences in drug release cycles. Hydrophobic aerogels have broad application potential in fields such as controlled drug release, soft robotics, 3D printing, and wearable sensors.

[0005] In the prior art, when preparing hydrophobic aerogels, liquid-phase hydrophobicity or gas-phase hydrophobicity is usually used to modify the aerogel mat or gel mat. However, the hydrophobic modification process requires separate operation steps and equipment, is time-consuming, consumes a large amount of hydrophobic agent, and leaves a large amount of unreacted hydrophobic agent residue on the surface of the finished product. [Summary of the Invention]

[0006] This application provides a method for preparing hydrophobic aerogels, composite materials thereof, preparation methods thereof, and battery devices.

[0007] To solve the above-mentioned technical problems, one technical solution adopted in this application is: to provide a method for preparing a hydrophobic aerogel, the method comprising: mixing a precursor hydrolysate, a catalyst and a hydrophobic agent to form a prepolymer mixture, reacting the prepolymer mixture to obtain a prepolymer wet gel; and drying the prepolymer wet gel.

[0008] To solve the above-mentioned technical problems, another technical solution adopted in this application is: to provide a method for preparing a hydrophobic aerogel composite material, providing a prepolymer mixture in the preparation method of the hydrophobic aerogel provided in the above embodiments; mixing the prepolymer mixture with a matrix, reacting the prepolymer mixture to obtain a prepolymer wet gel; and drying the prepolymer wet gel.

[0009] To solve the above-mentioned technical problems, another technical solution adopted in this application is: to provide a hydrophobic aerogel composite material, wherein the hydrophobic aerogel composite material is prepared by the preparation method of the hydrophobic aerogel provided in the above embodiments; wherein, after the hydrophobic aerogel composite material is immersed in water for 30 minutes and then removed, the weight increase is less than or equal to 10% of the initial weight.

[0010] To solve the above-mentioned technical problems, another technical solution adopted in this application is: to provide a battery device, including a housing, a plurality of battery cells and a heat insulation component; the plurality of battery cells are disposed in the housing; the heat insulation component is disposed between the plurality of battery cells; the material of the separator is the hydrophobic aerogel composite material provided in the above embodiments.

[0011] The beneficial effects of this application are as follows: By directly using the precursor hydrolysate, this application omits the precursor hydrolysis step. When reacting with the hydrophobic agent, the hydrophobic agent will no longer participate in the precursor hydrolysis and will participate more in the modification reaction, reducing the consumption of the hydrophobic agent. Moreover, this application does not require a separate hydrophobic modification operation step and device. Therefore, the preparation method of hydrophobic aerogel provided by this application is simpler to operate, more environmentally friendly, and more cost-effective. [Attached Image Description]

[0012] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 is a flowchart of a method for preparing hydrophobic aerogels provided in some embodiments of this application.

[0014] Figure 2 is a flowchart of step S10 in Figure 1 provided in some embodiments of this application.

[0015] Figure 3 is a flowchart of step S10 in Figure 1 provided in some other embodiments of this application.

[0016] Figure 4 is a flowchart of step S10 in Figure 1 provided in some embodiments of this application.

[0017] Figure 5 is a flowchart of step S10 in Figure 1 provided in some embodiments of this application.

[0018] Figure 6 is a flowchart of a method for preparing hydrophobic aerogel composite materials provided in some embodiments of this application.

[0019] Figure 7 is a flowchart of steps S200 and S300 in Figure 6 provided in some embodiments of this application.

[0020] Figure 8 is a schematic diagram of the structure of a battery device provided in some embodiments of this application. 【Detailed Implementation Methods】

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0022] In the description of this application, it should be understood that the orientations or positional relationships indicated by terms such as "center," "middle," "inner," "outer," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise" are based on the orientations and positional relationships shown in the accompanying drawings. They are used merely for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0023] This application is based on the inventor's discoveries and understanding of the following facts and problems:

[0024] In the existing technology, when preparing hydrophobic aerogels, liquid-phase hydrophobicity or gas-phase hydrophobicity is usually used to modify the aerogel mat or gel mat. However, the hydrophobic modification process requires separate operation steps and equipment, which is time-consuming, consumes a lot of hydrophobic agents, and leaves a large amount of unreacted hydrophobic agent organic matter residue on the surface of the finished product, resulting in poor combustion performance.

[0025] Alternatively, the hydrophobic agent can be premixed with silica sol before adding a catalyst to gel, or the hydrophobic agent can be premixed with a catalyst before adding silica sol to gel. However, since the hydrophobic agent participates in both the hydrolysis and gelation processes, the amount of hydrophobic agent involved in the modification is reduced, resulting in more hydrophobic agent being consumed and causing material waste.

[0026] Based on the above findings, the inventors of this application provide a method for preparing a hydrophobic aerogel. Referring to Figure 1, the method for preparing the hydrophobic aerogel includes:

[0027] Step S10: Mix the precursor hydrolysate, catalyst and hydrophobic agent to form a prepolymer mixture, and react the prepolymer mixture to obtain a prepolymer wet gel.

[0028] In the context of material preparation, precursor hydrolysate refers to the solution formed during the hydrolysis of precursor substances used to form the target material, particularly in the sol-gel process. Precursors are a form of existence prior to obtaining the target product; they mostly exist as organic-inorganic complexes or mixed solids, and some exist in sol form. In the sol-gel process, precursors are typically metal alkoxides. These metal alkoxides can undergo hydrolysis to form hydrolysate, and the components in the hydrolysate undergo condensation reactions to form a sol, which in turn forms a gel.

[0029] The precursor is related to the type of hydrophobic aerogel being prepared. For example, when preparing silicon oxide hydrophobic aerogels, the precursor is a silicon source precursor; when preparing aluminum oxide hydrophobic aerogels, the precursor is an aluminum source; when preparing titanium oxide hydrophobic aerogels, the precursor is a titanium source; when preparing zirconium oxide hydrophobic aerogels, the precursor is a zirconium source; and when preparing copper oxide hydrophobic aerogels, the precursor is a copper source. This application uses silicon oxide hydrophobic aerogels as an example, with a silicon source as the precursor. The silicon source includes at least one of tetraethyl orthosilicate, tetramethyl orthosilicate, tetraisopropyl orthosilicate, and polysiloxane.

[0030] This application embodiment omits the precursor hydrolysis step by directly using the precursor hydrolysate. When reacting with the hydrophobic agent, the hydrophobic agent will no longer participate in the precursor hydrolysis, but will participate more in the modification reaction, thus reducing the consumption of the hydrophobic agent.

[0031] The catalyst is used to promote the formation of the wet gel. Since this application directly selects the precursor hydrolysate as the reaction solution, the catalyst may not have the function of promoting the hydrolysis of the silicon source. In the embodiments of this application, the catalyst can be an alkaline catalyst, such as ammonia, ammonium hydroxide, sodium hydroxide, or potassium hydroxide.

[0032] Hydrophobic agents reduce the surface tension of materials, causing liquids such as water to form discontinuous beads on the material surface, thereby giving the material waterproof, oil-proof, and stain-proof properties. Hydrophobic agents typically include organosilicon hydrophobic agents, organofluorine hydrophobic agents, hydrocarbon hydrophobic agents, wax-based hydrophobic agents, and polymeric hydrophobic agents. In this application, an organosilicon hydrophobic agent is used to prepare a silicon oxide hydrophobic aerogel, and the hydrophobic agent includes at least one selected from dimethyldiethoxysilane, methyltriethoxysilane, and propyltriethoxysilane.

[0033] In some embodiments of this application, by accelerating the gelation process and shortening the gelation time, the participation of the hydrophobic agent in the gelation process can be reduced, allowing the hydrophobic agent to participate in the modification as much as possible, thereby reducing the amount of hydrophobic agent used. Accelerating the gelation process can be achieved by adjusting the ambient temperature and the amount of catalyst used during the gelation process to regulate the gelation rate.

[0034] In some embodiments of this application, the ambient temperature for gelation of the prepolymer mixture can be controlled by recycling supercritical cooling waste liquid, and the ambient temperature can be 10℃-70℃, for example, 10℃, 20℃, 30℃, 40℃, 50℃, 60℃ or 70℃, etc. In other embodiments of this application, the ambient temperature for gelation of the prepolymer mixture is 30℃-50℃. In still other embodiments, the ambient temperature for gelation of the prepolymer mixture is 40℃-50℃. Within this ambient temperature range, the rate of hydrophobic reaction can be increased, the rate of gelation reaction can be reduced, the gelation time can be shortened, thereby reducing the amount of hydrophobic agent used, and ensuring that the obtained hydrophobic aerogel has good hydrophobic properties.

[0035] In some embodiments of this application, the mass ratio of the catalyst to the prepolymer mixture is between 3 / 1000 and 7 / 1000, for example, 3 / 1000, 4 / 1000, 5 / 1000, 6 / 1000, or 7 / 1000, etc., and the mass ratio of the hydrophobic agent to the prepolymer mixture is between 12.5 / 1000 and 125 / 1000, for example, 12.5 / 1000, 20 / 1000, 25 / 1000, 40 / 1000, 50 / 1000, 70 / 1000, 90 / 1000, 100 / 1000, 115 / 1000, or 125. / 1000, the mass ratio of silicon source to prepolymer mixture is between 100 / 1000 and 415 / 1000, for example, it can be 100 / 1000, 125 / 1000, 150 / 1000, 175 / 1000, 200 / 1000, 250 / 1000, 300 / 1000, 350 / 1000, 375 / 1000, 400 / 1000 or 415 / 1000, etc. Within this range, it can ensure that the obtained hydrophobic aerogel has good hydrophobic properties, and allow as many hydrophobic agents as possible to participate in the hydrophobic modification process, reducing the waste of hydrophobic agents.

[0036] In some embodiments of this application, the gelation time of the prepolymer mixture is 1-7 minutes (min), for example, it can be 1 min, 1.5 min, 2 min, 2.5 min, 3 min, 3.5 min, 4 min, 4.5 min, 5 min, 5.5 min, 6 min, 6.5 min or 7 min, etc. In other embodiments, the gelation time of the prepolymer mixture is 2-3 minutes. Within this time range, due to the shorter gelation time, the amount of hydrophobic agent involved in the gelation can be reduced, thereby reducing the amount of hydrophobic agent used. This also ensures that the resulting hydrophobic aerogel has good hydrophobic properties. If the gelation time is further shortened, it may lead to structural instability of the hydrophobic aerogel, thereby affecting its physical properties, such as strength and stability. It may also cause additional shrinkage of the gel block during the drying process, or even cracking and breakage, which will also affect the microstructure of the hydrophobic aerogel, thereby affecting the number and distribution of surface active groups of the functionalized hydrophobic aerogel and its adsorption performance. Furthermore, for embodiments that require the hydrophobic aerogel to be combined with a matrix (e.g., fiber felt, metal, ceramic, organic polymer, etc., this application uses fiber felt as an example) to form a hydrophobic aerogel composite material, if the gelation time is too short, the prepolymer mixture may gel before it has bonded with the fiber felt, resulting in a weak bond between the hydrophobic aerogel and the fiber felt. Moreover, this process is difficult to control, and the fiber felt may not absorb the prepolymer mixture sufficiently.

[0037] Furthermore, the timing of adding the hydrophobic agent has a significant impact on the product's performance and the amount of hydrophobic agent used. In some embodiments, please refer to Figure 2. Step S10 includes:

[0038] S11A: Prepolymer mixture is obtained by simultaneously mixing the precursor hydrolysate, catalyst and hydrophobic agent.

[0039] S12A: The prepolymer mixture undergoes a gelation reaction to obtain a wet prepolymer gel.

[0040] In this embodiment, simultaneous mixing of the precursor hydrolysate, catalyst, and hydrophobic agent refers to the process of mixing the precursor hydrolysate, catalyst, and hydrophobic agent together at the same time and place. In one embodiment, the reactor includes multiple inlets, and the precursor hydrolysate, catalyst, and hydrophobic agent are simultaneously added to the reactor through the corresponding inlets for mixing, and then stirred evenly by a stirrer. In another embodiment, pipes containing the precursor hydrolysate, catalyst, and hydrophobic agent can be simultaneously injected or sprayed into the reaction vessel, and then stirred evenly by a stirrer. The above are merely exemplary embodiments, and the simultaneous mixing methods in this application are not limited to these.

[0041] This embodiment simultaneously mixes the precursor hydrolysate, catalyst, and hydrophobic agent. Since the hydrophobic agent does not participate in the hydrolysis process, its consumption can be reduced. In some embodiments where a hydrophobic aerogel needs to be composited with a matrix (e.g., fiber mat) to form a hydrophobic aerogel composite material, the prepolymer mixture simultaneously contains the precursor hydrolysate, catalyst, and hydrophobic agent. Therefore, the fiber mat can simultaneously absorb the precursor hydrolysate, catalyst, and hydrophobic agent. Compared to adding the hydrophobic agent later, this reduces the problem that after the fiber mat is saturated with the precursor hydrolysate and catalyst, the added hydrophobic agent is difficult to bind to the fiber mat, meaning it flows away and does not easily remain on the fiber mat to react hydrophobically with the sol-gel.

[0042] Optionally, in some other embodiments, referring to FIG3, step S10 includes:

[0043] S11B: First, mix the precursor hydrolysate and the catalyst, then add a hydrophobic agent to obtain a prepolymer mixture;

[0044] S12B: The prepolymer mixture undergoes a gelation reaction to obtain a wet prepolymer gel.

[0045] In this embodiment, the precursor hydrolysate and catalyst begin to react immediately after mixing. In some embodiments, the hydrophobic agent is added within 1 minute of mixing the precursor hydrolysate and catalyst, at which point gelation has not yet begun. This method increases the gelation time compared to simultaneous mixing, as the hydrophobic agent participates in part of the gelation process. The hydrophobic agent reacts with the hydroxyl groups of the aerogel. The hydrophobic agent has a capping group that prevents condensation between aerogel segments, thus leading to segment growth and a soft, flexible finished product. In other embodiments, for those requiring the composite formation of hydrophobic aerogel with a matrix (e.g., fiber felt) to form a hydrophobic aerogel composite material, the hydrophobic agent is added within 1 minute of mixing the precursor hydrolysate and catalyst. Then, the hydrophobic agent is added within 7 minutes. At this time, gelation has been formed, but the gelation reaction is not completely completed. After being placed on the fiber felt and before rolling, the hydrophobic agent is brushed onto the surface of the fiber felt that has absorbed the adhesive solution. The hydrophobic agent can penetrate into the interior through the gaps in the fiber felt, and the hydrophobic agent can be fully utilized, thereby reducing the amount of hydrophobic agent used. In some other embodiments, the hydrophobic agent is added 7 minutes after the precursor hydrolysate and catalyst are mixed. At this time, the gelation reaction has been completed. For embodiments that need to be compounded with fiber felt, since the fiber felt is saturated with adhesive solution after gelation, the hydrophobic agent cannot be added in one go for thicker fiber felts. It needs to be added repeatedly, which may result in insufficient addition of hydrophobic agent and prolong the preparation period.

[0046] Optionally, in some other embodiments, referring to FIG4, step S10 includes:

[0047] S11C: First, the precursor hydrolysate and hydrophobic agent are mixed, and then the catalyst is added to obtain the prepolymer mixture.

[0048] S12C: The prepolymer mixture undergoes a gelation reaction to obtain a wet prepolymer gel.

[0049] In this embodiment, the precursor hydrolysate and the hydrophobic agent are mixed first, and the two will basically not undergo a gelation process. After the catalyst is added, the gel formation is accelerated due to the action of the catalyst. Since the hydrophobic agent does not participate in the hydrolysis process of the precursor, the amount of hydrophobic agent can be reduced.

[0050] Optionally, in some other embodiments, referring to FIG5, step S10 includes:

[0051] S11D: After mixing the catalyst and hydrophobic agent, add them to the precursor hydrolysate to obtain a prepolymer mixture;

[0052] S12D: The prepolymer mixture undergoes a gelation reaction to obtain a wet prepolymer gel.

[0053] In embodiments using silicone hydrophobic agents, the silicone hydrophobic agents may consume a portion of the catalyst, thereby affecting the subsequent gelation and modification process of the precursor hydrolysate, and prolonging the gelation time.

[0054] Step S20: Dry the prepolymer wet gel.

[0055] The prepolymer gel is dried and aged to obtain a hydrophobic aerogel. Optionally, the wet prepolymer gel can be dried using supercritical drying to obtain the hydrophobic aerogel. Optionally, the supercritical drying process uses supercritical ethanol drying or supercritical carbon dioxide drying. Optionally, the wet prepolymer gel can be dried at atmospheric pressure for 0.5 hours to 2 hours to obtain the hydrophobic aerogel.

[0056] Furthermore, in some embodiments, the hydrophobic aerogel needs to be composited with a matrix to form a hydrophobic aerogel composite material, with the matrix providing support for the hydrophobic aerogel. In some embodiments, the matrix can be a fiber felt, which serves as a reinforcing material. For example, it can include rock wool fiber felt, glass fiber needled felt, high-silica needled felt, alumina fiber felt, mullite fiber felt, alumina fiber felt, or ceramic pre-oxidized filaments, etc., which can significantly improve the mechanical strength and toughness of the hydrophobic aerogel, solving the problem of easy damage when used alone. In addition, the fiber felt can also inhibit the shrinkage of the aerogel at high temperatures, improving the high-temperature insulation performance of the hydrophobic aerogel. Some embodiments of this application provide a method for preparing a hydrophobic aerogel composite material. Please refer to Figure 6. The method for preparing the hydrophobic aerogel composite material includes:

[0057] S100: Provide a prepolymer mixture in the preparation method of the hydrophobic aerogel provided in any of the above embodiments;

[0058] S200: The prepolymer mixture is mixed with the matrix, and the prepolymer mixture reacts to obtain a prepolymer wet gel;

[0059] S300: Dry the prepolymer wet gel.

[0060] In step S100, the prepolymer mixture preparation method is the same as the prepolymer mixture involved in the preparation method for preparing hydrophobic aerogel provided in the foregoing embodiments.

[0061] The matrix may include fiber felt, metal, ceramic or organic polymer, etc. In some embodiments, the matrix includes fiber felt, see Figure 7. Step S200 includes:

[0062] S201: The prepolymer mixture is formed directly on the fiber felt, or the prepolymer mixture is placed on the fiber felt.

[0063] In some embodiments, a prepolymer mixture of precursor hydrolysate, hydrophobic agent and catalyst can be sprayed onto the fiber felt; in other embodiments, the precursor hydrolysate and catalyst can be combined with the fiber felt first, and then the hydrophobic agent can be sprayed onto the fiber felt. The embodiments of this application are not limited to these.

[0064] S202: Gel the prepolymer mixture on the fiber felt to obtain a wet gel / fiber felt composite material.

[0065] Optionally, please continue to refer to Figure 7, step S300 includes:

[0066] S301: Dry the wet gel on the fiber felt to obtain a hydrophobic aerogel / fiber felt composite material.

[0067] The embodiments and comparative examples of this application are described below in a straightforward manner. Since the properties of hydrophobic aerogels are not easily tested individually, hydrophobic aerogel composite materials are used to characterize their properties. It is understood that since the matrix (e.g., fiber mat) used in each embodiment is the same, the properties characterized using the hydrophobic aerogel composite material and the trend of its performance changes can also reflect the properties and trends of the hydrophobic aerogel. Examples 1-6 and Comparative Examples 1-6 investigated the effect of catalyst dosage on the hydrophobic properties of the prepared hydrophobic aerogel when the ambient temperature during gelation of the prepolymer mixture was 35°C. Examples 7-12 and Comparative Examples 7-12 investigated the effect of the ambient temperature during gelation of the prepolymer mixture when the mass ratio of catalyst to prepolymer mixture was 4 / 1000 on the hydrophobic properties of the prepared hydrophobic aerogel composite material.

[0068] Example 1

[0069] Example 1 of this application describes the preparation of a hydrophobic aerogel composite material according to steps S100-S300 described above. The ambient temperature during gelation of the prepolymer mixture is 35°C. The mass ratio of the catalyst to the prepolymer mixture is 3 / 1000, 4 / 1000, 5 / 1000, 6 / 1000, and 7 / 1000, respectively, and the mass ratio of the hydrophobic agent to the prepolymer mixture is 18.75 / 1000. In Examples 1-1 to 1-3, the hydrophobic agents are dimethyldiethoxysilane, methyltriethoxysilane, and methyltriethoxysilane, respectively.

[0070] Example 2

[0071] The preparation methods of the hydrophobic aerogel composite material in Example 2 of this application are basically the same as those in Example 1. The difference is that in Example 2 of this application, the mass ratio of the hydrophobic agent to the prepolymer mixture is 25 / 1000.

[0072] Example 3

[0073] The preparation methods of the hydrophobic aerogel composite material in Example 3 of this application are basically the same as those in Example 1. The difference is that in Example 3 of this application, the mass ratio of the hydrophobic agent to the prepolymer mixture is 31.25 / 1000.

[0074] Example 4

[0075] The preparation methods of the hydrophobic aerogel composite material in Example 3 of this application are basically the same as those in Example 1. The difference is that in Example 4 of this application, the mass ratio of the hydrophobic agent to the prepolymer mixture is 37.5 / 1000.

[0076] Example 5

[0077] The preparation methods of the hydrophobic aerogel composite material in Example 3 of this application are basically the same as those in Example 1. The difference is that in Example 5 of this application, the mass ratio of the hydrophobic agent to the prepolymer mixture is 50 / 1000.

[0078] Example 6

[0079] The preparation methods of the hydrophobic aerogel composite material in Example 6 of this application are basically the same as those in Example 1. The difference is that in Example 6 of this application, the mass ratio of the hydrophobic agent to the prepolymer mixture is 62.5 / 1000.

[0080] Example 7

[0081] The preparation methods of the hydrophobic aerogel composite material in Example 7 of this application are basically the same as those in Example 1. The difference is that in Example 7 of this application, the mass ratio of the hydrophobic agent to the prepolymer mixture is fixed at 62.5 / 1000, and the ambient temperatures when the prepolymer mixture gels are 30℃, 35℃, 40℃, 45℃, and 50℃, respectively.

[0082] Example 8

[0083] The preparation methods of the hydrophobic aerogel composite materials in Example 8 and Example 7 of this application are basically the same, except that in Example 7 of this application, the mass ratio of the hydrophobic agent to the prepolymer mixture is 25 / 1000.

[0084] Example 9

[0085] The preparation methods of the hydrophobic aerogel composite materials in Example 9 and Example 7 of this application are basically the same. The difference is that in Example 3 of this application, the mass ratio of the hydrophobic agent to the prepolymer mixture is 31.25 / 1000.

[0086] Example 10

[0087] The preparation methods of the hydrophobic aerogel composite materials in Examples 10 and 7 of this application are basically the same, except that in Example 4 of this application, the mass ratio of the hydrophobic agent to the prepolymer mixture is 37.5 / 1000.

[0088] Example 11

[0089] The preparation methods of the hydrophobic aerogel composite materials in Example 11 and Example 7 of this application are basically the same, except that in Example 5 of this application, the mass ratio of the hydrophobic agent to the prepolymer mixture is 50 / 1000.

[0090] Example 12

[0091] The preparation methods of the hydrophobic aerogel composite materials in Example 12 and Example 7 of this application are basically the same. The difference is that in Example 6 of this application, the mass ratio of the hydrophobic agent to the prepolymer mixture is 62.5 / 1000.

[0092] Comparative Examples 1-12

[0093] The preparation methods of the hydrophobic aerogel composite materials of Comparative Examples 1-12 in this application are basically the same as those of the hydrophobic aerogel composite materials of Examples 1-12, and correspond one-to-one. The difference is that the precursor used in Examples 1-12 of this application is a precursor hydrolysate, while the precursor used in Comparative Examples 1-12 is an unhydrolyzed precursor raw material. For example, the precursor used in Examples 1-12 of this application is a silicon source hydrolysate, while the precursor used in Comparative Examples 1-12 is a silicon source powder.

[0094] After obtaining the hydrophobic aerogel composite materials of Examples 1-12 and Comparative Examples 1-12, the hydrophobic properties of each hydrophobic aerogel composite material were further tested. The test method was to immerse each hydrophobic aerogel composite material in water for 30 minutes and then take it out, and measure the percentage increase in weight of the hydrophobic aerogel composite material after immersion. The test results are shown in Tables 1-4.

[0095] As can be seen from Examples 1-6, the higher the catalyst content, the shorter the gelation time, the faster the gelation rate, and the higher the hydrophobic agent content, the more the hydrophobic aerogel composite material increases in weight by about 10% after being soaked in water for 30 minutes. The better the hydrophobic performance, the higher the catalyst and hydrophobic agent content should be. Considering the production cost, the use of catalyst and hydrophobic agent should not be too high. When the hydrophobic agent is dimethyldiethoxysilane, the mass ratio of catalyst to prepolymer mixture is 5 / 1000-7 / 1000, and the mass ratio of hydrophobic agent to prepolymer mixture is 25 / 1000-62.5 / 1000; and when the hydrophobic agent is propyltriethoxysilane, the mass ratio of catalyst to prepolymer mixture is 5 / 1000-7 / 1000, and the mass ratio of hydrophobic agent to prepolymer mixture is 37.5 / 1000-62.5 / 1000. The resulting hydrophobic aerogel composite material, after being immersed in water for 30 minutes, increases in weight by about 10% of the initial weight, indicating good hydrophobic properties. When the hydrophobic agent is methyltriethoxysilane, the hydrophobicity of the resulting hydrophobic aerogel composite material is not as good as the scheme using dimethyldiethoxysilane and propyltriethoxysilane.

[0096] As can be seen from Examples 7-12, the higher the temperature, the shorter the gelation time, and the faster the gelation rate. The hydrophobic aerogel composite material obtained after being soaked in water for 30 minutes increases in weight by about 10% of the initial weight, indicating better hydrophobic properties. However, higher temperatures require more sophisticated reaction equipment and consume more energy, which is not conducive to cost control. When dimethyldiethoxysilane is used as the hydrophobic agent, the ambient temperature for the reaction of the prepolymer mixture to obtain the prepolymer wet gel is 10℃-70℃, and the mass ratio of the hydrophobic agent to the prepolymer mixture is 25 / 1000-62.5 / 1000. When propyltriethoxysilane is used as the catalyst, the ambient temperature for the reaction of the prepolymer mixture to obtain the prepolymer wet gel is 10℃-70℃, and the mass ratio of the hydrophobic agent to the prepolymer mixture is 37.5 / 1000-62.5 / 1000. The resulting hydrophobic aerogel composite material, after being immersed in water for 30 minutes, increases in weight by about 10% of its initial weight, indicating good hydrophobic properties.

[0097] As shown in Examples 1-12 and Comparative Examples 1-12, when the hydrophobic agent is dimethyldiethoxysilane, under the same conditions and with the same materials, the hydrophobic aerogel composite material prepared using the precursor hydrolysate (silicon source hydrolysate) in this application shows a significant improvement in hydrophobic properties compared to the hydrophobic aerogel composite material prepared using the unhydrolyzed precursor; when the hydrophobic agent is methyltriethoxysilane, the hydrophobic properties of the hydrophobic aerogel composite material prepared using the silicon source hydrolysate in this application show little change compared to the hydrophobic aerogel composite material prepared using the unhydrolyzed silicon source; when the catalyst is propyltriethoxysilane... When using ethoxysilane, under the conditions that the mass ratio of catalyst to prepolymer mixture is 5 / 1000-7 / 1000, the mass ratio of hydrophobic agent to prepolymer mixture is 37.5 / 1000-62.5 / 1000, and the ambient temperature at which the prepolymer wet gel is obtained by reacting the prepolymer mixture is 10℃-70℃, the hydrophobic aerogel composite material prepared using silicon source hydrolysate in the embodiments of this application has significantly improved hydrophobic properties compared to the hydrophobic aerogel composite material prepared using unhydrolyzed silicon source.

[0098] This application also studies the thermal insulation performance of hydrophobic aerogel composites. Specifically, the hydrophobic aerogel composites prepared using the methods provided in Examples 6-1 and 6-3 of Example 6 and Examples 12-1 and 12-3 of Example 12 of this application were tested, and the test results are shown in Table 5.

[0099] As shown in Table 5, when the hydrophobic agent is dimethyldiethoxysilane, the thermal conductivity of the hydrophobic aerogel composite material provided in this application embodiment is greater than 0.018 W / (m*K) and less than 0.022 W / (m*K); when the hydrophobic agent is propyltriethoxysilane, the thermal conductivity of the hydrophobic aerogel composite material provided in this application embodiment is greater than 0.018 W / (m*K) and less than 0.024 W / (m*K). Therefore, the hydrophobic aerogel composite material prepared by the method provided in this application embodiment has a relatively low thermal conductivity. This is because the hydrophobic aerogel composite material in this application is a porous network structure with nanoscale and / or microscale pores, making the heat conduction path in the solid skeleton extremely complex and lengthy, greatly reducing the efficiency of heat conduction through the solid skeleton. Furthermore, due to the high porosity in the hydrophobic aerogel composite material, the gas inside the pores is mainly air or other gases with low thermal conductivity, making heat conduction in the gas relatively difficult, further reducing the gas's thermal conductivity.

[0100] Based on the excellent hydrophobicity and / or thermal insulation properties of the hydrophobic aerogel and hydrophobic aerogel composite materials provided in this application, the hydrophobic aerogel composite materials provided in this application can be applied in the field of battery devices, such as thermal insulation components between battery cells.

[0101] Please refer to Figure 8. Some embodiments of this application provide a battery device 10, including a housing 11, a plurality of battery cells 12 and a heat insulation component 13. The plurality of battery cells 12 are disposed inside the housing 11, and the heat insulation component 13 is disposed between the plurality of battery cells 12. The material of the heat insulation component 13 is the hydrophobic aerogel provided in any of the above embodiments.

[0102] The material of the heat insulation component 13 in this application is the hydrophobic aerogel provided in the embodiments of this application. Since the hydrophobic aerogel has excellent heat insulation performance, it can reduce the risk of heat being conducted to adjacent battery cells 12 after one of the battery cells 12 experiences thermal runaway.

[0103] The technical solution provided in this application omits the precursor hydrolysis step by directly using the precursor hydrolysate. When reacting with the hydrophobic agent, the hydrophobic agent will no longer participate in the precursor hydrolysis and will participate more in the modification reaction, reducing the consumption of the hydrophobic agent. Moreover, this application does not require a separate hydrophobic modification operation step and device. Therefore, the preparation method of hydrophobic aerogel provided in this application is simpler to operate, more environmentally friendly, and more cost-effective.

[0104] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A method for preparing a hydrophobic aerogel, wherein, include: A precursor hydrolysate, a catalyst, and a hydrophobic agent are mixed to form a prepolymer mixture, and the prepolymer mixture is reacted to obtain a prepolymer wet gel. and The prepolymer wet gel is dried.

2. The method for preparing hydrophobic aerogel according to claim 1, wherein, The step of mixing the precursor hydrolysate, catalyst, and hydrophobic agent to form a prepolymer mixture, and reacting the prepolymer mixture to obtain a prepolymer wet gel, includes: The precursor hydrolysate, catalyst, and hydrophobic agent are mixed simultaneously; or First, mix the precursor hydrolysate and the catalyst, then add the hydrophobic agent; or First, mix the precursor hydrolysate and the hydrophobic agent, then add the catalyst; or The catalyst and the hydrophobic agent are mixed and then added to the precursor hydrolysate.

3. The method for preparing hydrophobic aerogel according to claim 1, wherein, In the step of mixing the precursor hydrolysate, catalyst, and hydrophobic agent to form a prepolymer mixture, and reacting the prepolymer mixture to obtain a prepolymer wet gel, the gelation time is 1-7 minutes.

4. The method for preparing hydrophobic aerogel according to claim 3, wherein, In the step of mixing the precursor hydrolysate, catalyst, and hydrophobic agent to form a prepolymer mixture, and reacting the prepolymer mixture to obtain a prepolymer wet gel, the gelation time is 2-3 minutes.

5. The method for preparing hydrophobic aerogel according to claim 1, wherein, The environmental temperature at which the prepolymer mixture reacts to obtain the prepolymer wet gel is 10℃-70℃.

6. The method for preparing hydrophobic aerogel according to claim 5, wherein, The prepolymer mixture reacts to obtain the prepolymer wet gel at an ambient temperature of 30℃-50℃.

7. The method for preparing hydrophobic aerogel according to claim 1, wherein, In the step of mixing the precursor hydrolysate, catalyst, and hydrophobic agent to form a prepolymer mixture, and reacting the prepolymer mixture to obtain a prepolymer wet gel, the mass ratio of the catalyst to the prepolymer mixture is between 3 / 1000 and 7 / 1000.

8. The method for preparing hydrophobic aerogel according to claim 1, wherein, In the step of mixing the precursor hydrolysate, catalyst, and hydrophobic agent to form a prepolymer mixture, and reacting the prepolymer mixture to obtain a prepolymer wet gel, the mass ratio of the hydrophobic agent to the prepolymer mixture is between 12.5 / 1000 and 125 / 1000.

9. The method for preparing hydrophobic aerogel according to claim 1, wherein, The precursor includes a silicon source; The hydrophobic agent includes at least one of dimethyldiethoxysilane, methyltriethoxysilane, and propyltriethoxysilane.

10. The method for preparing hydrophobic aerogel according to claim 1, wherein, The hydrophobic agent is dimethyldiethoxysilane; The mass ratio of the catalyst to the prepolymer mixture is 5 / 1000-7 / 1000; The mass ratio of the hydrophobic agent to the prepolymer mixture is between 25 / 1000 and 62.5 / 1000.

11. The method for preparing hydrophobic aerogel according to claim 1, wherein, The hydrophobic agent is propyltriethoxysilane; The mass ratio of the catalyst to the prepolymer mixture is 5 / 1000-7 / 1000; The mass ratio of the hydrophobic agent to the prepolymer mixture is between 37.5 / 1000 and 62.5 / 1000.

12. The method for preparing hydrophobic aerogel according to claim 1, wherein, The hydrophobic agent is dimethyldiethoxysilane; The environmental temperature at which the prepolymer mixture reacts to obtain the prepolymer wet gel is 10℃-70℃. The mass ratio of the hydrophobic agent to the prepolymer mixture is between 25 / 1000 and 62.5 / 1000.

13. The method for preparing hydrophobic aerogel according to claim 1, wherein, The catalyst is propyltriethoxysilane; The environmental temperature at which the prepolymer mixture reacts to obtain the prepolymer wet gel is 10℃-70℃. The mass ratio of the hydrophobic agent to the prepolymer mixture is between 37.5 / 1000 and 62.5 / 1000.

14. A method for preparing a hydrophobic aerogel composite material, wherein, include: Provide a prepolymer mixture in the preparation method of the hydrophobic aerogel according to any one of claims 1-13; The prepolymer mixture is mixed with the matrix, and the prepolymer mixture reacts to obtain a prepolymer wet gel; and The prepolymer wet gel is dried.

15. The method for preparing the hydrophobic aerogel composite material according to claim 14, wherein, The matrix includes a fiber felt, and the step of mixing the prepolymer mixture with the matrix and reacting the prepolymer mixture to obtain a prepolymer wet gel includes: The prepolymer mixture is formed directly on the fiber felt, or the prepolymer mixture is disposed on the fiber felt; and The prepolymer mixture on the fiber felt is gelled to obtain a wet gel / fiber felt composite material. The step of drying the wet gel includes drying the wet gel on the fiber felt to obtain a hydrophobic aerogel / fiber felt composite material.

16. A hydrophobic aerogel composite material, wherein, The hydrophobic aerogel is the hydrophobic aerogel composite material prepared by the preparation method of the hydrophobic aerogel composite material according to claim 14 or 15. The hydrophobic aerogel composite material, after being immersed in water for 30 minutes, increases in weight by less than or equal to 10% of its initial weight.

17. The hydrophobic aerogel composite material according to claim 16, wherein, The thermal conductivity of the hydrophobic aerogel composite material is greater than 0.018 W / (m*K) and less than 0.025 W / (m*K).

18. A battery device comprising: Box; Multiple battery cells are disposed within the housing; and A heat insulation element is disposed between multiple battery cells; The material of the thermal insulation component is the hydrophobic aerogel composite material as described in claim 16 or 17.

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