Preparation method of hydrophobic aerogel, composite material, preparation method of composite material and battery device

Abstract

The invention discloses a preparation method of hydrophobic aerogel, a composite material, a preparation method of the composite material and a battery device. The preparation method of the hydrophobic aerogel comprises the following steps: mixing a precursor hydrolysate, a catalyst and a hydrophobic agent to form a prepolymer mixed solution, and carrying out a reaction on the prepolymer mixed solution to obtain a prepolymer wet gel; and drying the wet gel of the prepolymer. According to the mode, the precursor hydrolysate is directly used, the step of precursor hydrolysis is omitted, when the precursor hydrolysate reacts with the hydrophobing agent, the hydrophobing agent does not participate in precursor hydrolysis and more participates in modification reaction, consumption of the hydrophobing agent is reduced, independent hydrophobic modification operation steps and devices do not need to be arranged, and therefore the hydrophobic modification effect is greatly improved. The preparation method of the hydrophobic aerogel provided by the invention is simpler to operate, more environment-friendly and more cost-saving.

Description

Technical Field

[0001] The present application relates to the field of hydrophobic aerogels, and in particular to a method for preparing hydrophobic aerogels, a composite material and a preparation method, and a battery device. Background Art

[0002] Hydrophobic aerogel is a special type of hydrogel that contains a certain amount of hydrophobic fragments or hydrophobic groups. These groups can be side groups on the gel grid or side groups of chain polymers embedded in the gel. Due to the interaction of its internal hydrophobic groups, hydrophobic aerogels exhibit unique environmental stimulus response characteristics, such as the response relationship to changes in pH, temperature, solvent, etc., as well as differences in drug release cycles. Hydrophobic aerogels have broad application potential in the fields of drug controlled release, soft robotics, 3D printing, wearable sensors, etc.

[0003] In the prior art, when preparing hydrophobic aerogels, liquid phase hydrophobicity or gas phase hydrophobicity is usually used to modify the aerogel felt or gel felt. However, since the hydrophobic modification process requires separate operating steps and equipment, it is time-consuming, consumes a large amount of hydrophobic agent, and there will be a large amount of unreacted hydrophobic agent residue on the surface of the finished product. Summary of the invention

[0004] The present application provides a preparation method of a hydrophobic aerogel, a composite material and a preparation method thereof, a composite material and a preparation method thereof, and a battery device.

[0005] In order to solve the above technical problems, a technical solution adopted in the present application is: to provide a method for preparing a hydrophobic aerogel, the method for preparing the hydrophobic aerogel comprising: mixing a precursor hydrolyzate, 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.

[0006] In order to solve the above technical problems, another technical solution adopted in the present application is: providing a method for preparing a hydrophobic aerogel composite material, providing a prepolymer mixed liquid in the method for preparing the hydrophobic aerogel provided in the above embodiment; mixing the prepolymer mixed liquid with a matrix, and reacting the prepolymer mixed liquid to obtain a prepolymer wet gel; and drying the prepolymer wet gel.

[0007] In order to solve the above technical problems, another technical solution adopted in the present application is: to provide a hydrophobic aerogel composite material, which is a hydrophobic aerogel composite material prepared by the hydrophobic aerogel preparation method provided in the above embodiment; wherein, after the hydrophobic aerogel composite material is taken out after being immersed in water for 30 minutes, the increased weight is less than or equal to 10% of the initial weight.

[0008] In order to solve the above technical problems, another technical solution adopted in the present application is: to provide a battery device, including a box, multiple battery cells and a thermal insulation member; multiple battery cells are arranged in the box; the thermal insulation member is arranged between the multiple battery cells; the material of the diaphragm is the hydrophobic aerogel composite material provided in the above embodiment.

[0009] The beneficial effects of the present application are as follows: the present application omits the step of hydrolyzing the precursor by directly using a precursor hydrolyzate; when reacting with a hydrophobic agent, the hydrophobic agent no longer participates in the hydrolysis of the precursor, but participates more in the modification reaction, thereby reducing the consumption of the hydrophobic agent; and the present application does not require the setting of separate hydrophobic modification operation steps and devices; therefore, the method for preparing the hydrophobic aerogel provided by the present application is simpler to operate, more environmentally friendly, and more cost-effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0011] Figure 1 It is a flow chart of a method for preparing a hydrophobic aerogel provided in some embodiments of the present application.

[0012] Figure 2 Some embodiments of the present application provide Figure 1 Flow chart of step S10 in FIG.

[0013] Figure 3 Other embodiments of the present application provide Figure 1 Flow chart of step S10 in FIG.

[0014] Figure 4 Some embodiments of the present application provide Figure 1 Flow chart of step S10 in FIG.

[0015] Figure 5 Some embodiments of the present application provide Figure 1 Flow chart of step S10 in FIG.

[0016] Figure 6 It is a flow chart of a method for preparing a hydrophobic aerogel composite material provided in some embodiments of the present application.

[0017] Figure 7 Some embodiments of the present application provide Figure 6 Flowchart of steps S200 and S300 in FIG.

[0018] Figure 8A schematic diagram of the structure of a battery device provided in some embodiments of the present application. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] In the description of the present application, it should be understood that the orientations or positional relationships indicated by “center”, “middle”, “inside”, “outside”, “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, etc. are based on the orientations and positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms “first” and “second” are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as “first” and “second” may explicitly or implicitly include one or more of the said features. In the description of the present application, the meaning of “multiple” is two or more, unless otherwise clearly and specifically defined.

[0021] This application is based on the inventor's discovery and understanding of the following facts and problems:

[0022] In the prior art, when preparing hydrophobic aerogels, liquid phase hydrophobicity or gas phase hydrophobicity is usually used to modify the aerogel felt or gel felt. However, since the hydrophobic modification process requires separate operating steps and equipment, it is time-consuming, consumes a large amount of hydrophobic agent, and there will be a large amount of unreacted hydrophobic agent organic matter remaining on the surface of the finished product, resulting in poor combustion performance.

[0023] In addition, the hydrophobic agent and the silica sol may be premixed in advance and then a catalyst may be added for gelation, or the hydrophobic agent and the catalyst may be premixed in advance and then silica sol may be added for gelation. However, since the hydrophobic agent participates in both the hydrolysis process and the gelation process, the amount of hydrophobic agent involved in the modification is reduced, resulting in more hydrophobic agent being consumed, causing waste of materials.

[0024] Based on the above findings, the inventors of the present application provide a method for preparing a hydrophobic aerogel, see Figure 1 , the preparation method of the hydrophobic aerogel comprises:

[0025] Step S10: mixing the precursor hydrolyzate, the catalyst and the hydrophobic agent to form a prepolymer mixture, and reacting the prepolymer mixture to obtain a prepolymer wet gel.

[0026] Among them, the precursor hydrolyzate refers to the solution formed during the hydrolysis process of the precursor substance used to form the target material during the material preparation process, especially in the sol-gel method. The precursor is a form of existence before obtaining the target product. Most of them exist in the form of organic-inorganic complexes or mixed liquid solids, and some exist in the form of sols. In the sol-gel method, the precursor usually refers to metal alkoxides, which can be hydrolyzed to form a hydrolyzate. The components in the hydrolyzate undergo condensation reactions to form a sol, and then a gel.

[0027] The precursor is related to the type of hydrophobic aerogel prepared. For example, when preparing silicon oxide hydrophobic aerogel, the precursor is a silicon source precursor; when preparing aluminum oxide hydrophobic aerogel, the precursor is an aluminum source; when preparing titanium oxide hydrophobic aerogel, the precursor is a titanium source; when preparing zirconium oxide hydrophobic aerogel, the precursor is a zirconium source; when preparing copper oxide hydrophobic aerogel, the precursor is a copper source. The embodiment of the present application takes silicon oxide hydrophobic aerogel as an example for introduction. The precursor is a silicon source, and the silicon source includes at least one of tetraethyl orthosilicate, tetramethyl orthosilicate, tetraisopropyl orthosilicate and polysiloxane.

[0028] The embodiment of the present application omits the step of hydrolyzing the precursor by directly using the precursor hydrolyzate. When reacting with the hydrophobic agent, the hydrophobic agent will no longer participate in the hydrolysis of the precursor, but will participate more in the modification reaction, thereby reducing the consumption of the hydrophobic agent.

[0029] The catalyst is used to promote the formation of wet gel. Since the present application directly uses the precursor hydrolyzate as the reaction liquid, the catalyst may not have the function of promoting the hydrolysis of the silicon source when selecting the catalyst. In the embodiment of the present application, the catalyst may be an alkaline catalyst, such as ammonia, ammonium hydroxide, sodium hydroxide or potassium hydroxide.

[0030] The hydrophobic agent reduces the surface tension of the material surface, so that liquids such as water form discontinuous beads on the material surface, thereby making the material waterproof, oil-proof and antifouling. Hydrophobic agents generally include organosilicon hydrophobic agents, organic fluorine hydrophobic agents, hydrocarbon hydrophobic agents, wax hydrophobic agents and polymer hydrophobic agents. In the embodiment of the present application, an organosilicon hydrophobic agent is used to prepare silicon oxide hydrophobic aerogel, and the hydrophobic agent includes at least one of dimethyldiethoxysilane, methyltriethoxysilane and propyltriethoxysilane.

[0031] In some embodiments of the present application, the participation of the hydrophobic agent in the gelation process can be reduced by accelerating the gelation process and shortening the gelation time, so that the hydrophobic agent can participate in the modification as much as possible, thereby reducing the amount of the hydrophobic agent. The gelation process can be accelerated by adjusting the ambient temperature and the amount of the catalyst used in the gelation process to adjust the gelation rate.

[0032] In some embodiments of the present 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°C-70°C, for example, 10°C, 20°C, 30°C, 40°C, 50°C, 60°C or 70°C, etc.; in other embodiments of the present application, the ambient temperature for gelation of the prepolymer mixture is 30°C-50°C; in still other embodiments, the ambient temperature for gelation of the prepolymer mixture is 40°C-50°C. Within this ambient temperature range, the rate of participating in the hydrophobic reaction can be increased, the rate of participating in the gelation reaction can be reduced, the gelation time can be shortened, and the amount of hydrophobic agent used can be reduced, and it can also be ensured that the obtained hydrophobic aerogel has good hydrophobic properties.

[0033] In some embodiments of the present application, the mass ratio of the catalyst to the prepolymer mixture is 3 / 1000-7 / 1000, for example, 3 / 1000, 4 / 1000, 5 / 1000, 6 / 1000 or 7 / 1000, and the mass ratio of the hydrophobic agent to the prepolymer mixture is 12.5 / 1000-125 / 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 the silicon source to the prepolymer mixture is 100 / 1000-415 / 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 be ensured that the obtained hydrophobic aerogel has good hydrophobic properties and as many hydrophobic agents as possible can be involved in the hydrophobic modification process to reduce the waste of the hydrophobic agent.

[0034] In some embodiments of the present application, the gel 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. In other embodiments, the gelation time of the prepolymer mixture is 2-3 minutes. Within this time range, due to the short gelation time, the hydrophobic agent involved in the gelation can be reduced, thereby reducing the amount of the hydrophobic agent used, and ensuring that the obtained hydrophobic aerogel has good hydrophobic properties. If the gelation time is further shortened, the structure of the hydrophobic aerogel may be unstable, thereby affecting its physical properties, such as strength and stability. It may also cause the gel block to produce additional shrinkage during the drying process, or even crack and break, 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 in which the hydrophobic aerogel and a matrix (for example, fiber felt, metal, ceramic, organic polymer, etc., the embodiments of the present application are introduced by taking fiber felt as an example) need to be compounded to form a hydrophobic aerogel composite material, if the gelation time is too short, the prepolymer mixture may gel before it is combined with the fiber felt, so that the obtained hydrophobic aerogel is not firmly combined with the fiber felt; and the process is difficult to control, and it is easy for the fiber felt to absorb the prepolymer mixture insufficiently.

[0035] Furthermore, the timing of adding the hydrophobic agent has a great influence on the performance of the product and the amount of the hydrophobic agent used. In some embodiments, see Figure 2 , step S10 comprises:

[0036] S11A: mixing a precursor hydrolyzate, a catalyst and a hydrophobic agent simultaneously to obtain a prepolymer mixed solution;

[0037] S12A: The prepolymer mixture undergoes a gel reaction to obtain a prepolymer wet gel.

[0038] In the present embodiment, the simultaneous mixing of the precursor hydrolyzate, the catalyst and the hydrophobic agent refers to the process in which the precursor hydrolyzate, the catalyst and the hydrophobic agent are mixed together at the same time and at the same place. In one embodiment, the reactor includes a plurality of feed ports, and the precursor hydrolyzate, the catalyst and the hydrophobic agent are simultaneously added to the reactor through the corresponding feed ports for mixing, and then stirred evenly by a stirrer. In another embodiment, the pipes respectively equipped with the precursor hydrolyzate, the catalyst and the hydrophobic agent can be simultaneously injected or sprayed into the reaction vessel, and then stirred evenly by a stirrer. The above is only an exemplary embodiment, and the method of simultaneous mixing of the present application is not limited thereto.

[0039] In this embodiment, the precursor hydrolyzate, catalyst and hydrophobic agent are mixed at the same time, and the hydrophobic agent does not participate in the hydrolysis process, so the consumption of the hydrophobic agent can be reduced. In some embodiments, for embodiments in which the hydrophobic aerogel needs to be compounded with a matrix (such as a fiber felt) to form a hydrophobic aerogel composite material, the prepolymer mixture contains the precursor hydrolyzate, catalyst and hydrophobic agent at the same time. Therefore, the fiber felt can absorb the precursor hydrolyzate, catalyst and hydrophobic agent at the same time. Compared with the solution of adding the hydrophobic agent later, it can reduce the problem that after the fiber felt absorbs the precursor hydrolyzate and catalyst to saturation, the hydrophobic agent is difficult to bind to the fiber felt after adding it, that is, the hydrophobic agent will flow away and is not easy to stay on the fiber felt to react with the sol-gel hydrophobicly.

[0040] Alternatively, in some other embodiments, see Figure 3 , step S10 comprises:

[0041] S11B: firstly mixing the precursor hydrolyzate and the catalyst, and then adding the hydrophobic agent to obtain a prepolymer mixed solution;

[0042] S12B: The prepolymer mixture undergoes a gel reaction to obtain a prepolymer wet gel.

[0043] In this embodiment, after the precursor hydrolyzate and the catalyst are mixed, the two begin to react. In some embodiments, the hydrophobic agent is added within 1 minute (min) after the precursor hydrolyzate and the catalyst are mixed. At this time, the gel has not yet begun to form. Compared with simultaneous mixing, the gel time will be increased in this way. The hydrophobic agent participates in part of the gel process. The hydrophobic agent reacts with the hydroxyl group of the aerogel. The hydrophobic agent has a blocking group, which prevents condensation between the aerogel segments. Therefore, the segments grow and the finished product is soft and easy to bend. In other embodiments, for embodiments where the hydrophobic aerogel needs to be compounded with a matrix (such as fiber felt) to form a hydrophobic aerogel composite material, the hydrophobic agent is added within 1 minute (min) after the precursor hydrolyzate and the catalyst are mixed. Afterwards, it is added within 7 minutes. At this time, gel has been produced but the gel reaction has not been completely completed. After it is set on the fiber felt and before it is rolled, the hydrophobic agent is brushed onto the surface of the fiber felt that absorbs the glue. The hydrophobic agent can penetrate into the interior through the gaps in the fiber felt. 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 hydrolyzate and the catalyst are mixed. At this time, the gel reaction has been completed. For the embodiments that need to be compounded with the fiber felt, since the fiber felt is saturated with glue after gelation, the single addition of the hydrophobic agent cannot add the required amount at one time for the thicker fiber felt, and it needs to be added repeatedly. There will be a phenomenon of insufficient amount of hydrophobic agent added, which also extends the preparation period.

[0044] Alternatively, in some other embodiments, see Figure 4 , step S10 comprises:

[0045] S11C: firstly mixing the precursor hydrolyzate and the hydrophobic agent, and then adding the catalyst to obtain a prepolymer mixed solution;

[0046] S12C: The prepolymer mixture undergoes a gel reaction to obtain a prepolymer wet gel.

[0047] In this embodiment, after the precursor hydrolyzate and the hydrophobic agent are first mixed, the two will basically not undergo a gel process. After the catalyst is added, the catalyst accelerates the formation of gel. Since the hydrophobic agent does not participate in the hydrolysis process of the precursor, the amount of the hydrophobic agent can be reduced.

[0048] Alternatively, in some other embodiments, see Figure 5 , step S10 comprises:

[0049] S11D: mixing the catalyst and the hydrophobic agent and adding the mixture to the precursor hydrolyzate to obtain a prepolymer mixture;

[0050] S12D: The prepolymer mixture undergoes a gel reaction to obtain a prepolymer wet gel.

[0051] For the embodiment using the organosilicon hydrophobic agent, the organosilicon hydrophobic agent may consume a portion of the catalyst, thereby affecting the subsequent gelation and modification process of the precursor hydrolyzate, and prolonging the gelation time.

[0052] Step S20: drying the prepolymer wet gel.

[0053] The prepolymer gel is dried and aged to obtain a hydrophobic aerogel. Optionally, the prepolymer wet gel can be dried by supercritical drying to obtain a hydrophobic aerogel. Optionally, the supercritical drying process uses supercritical ethanol drying or supercritical carbon dioxide drying. Optionally, the prepolymer wet gel can be dried at normal pressure for 0.5 hours to 2 hours to obtain a hydrophobic aerogel.

[0054] Furthermore, in some embodiments, the hydrophobic aerogel needs to be compounded with a matrix to form a hydrophobic aerogel composite material, and the matrix plays a supporting role for the hydrophobic aerogel. In some embodiments, the matrix can be a fiber felt, and the fiber felt serves as a reinforcing material. For example, it can include rock wool fiber felt, glass fiber needle felt, high silica needle felt, aluminum silicate fiber felt, mullite fiber felt, alumina fiber felt or ceramic pre-oxidized wire, etc., which can significantly improve the mechanical strength and toughness of the hydrophobic aerogel and solve the problem that the hydrophobic aerogel is easily damaged when used alone. In addition, the fiber felt can also inhibit the shrinkage of the aerogel at high temperatures and improve the high-temperature thermal insulation properties of the hydrophobic aerogel. Some embodiments of the present application provide a method for preparing a hydrophobic aerogel composite material, please refer to Figure 6 , the preparation method of the hydrophobic aerogel composite material comprises:

[0055] S100: providing a prepolymer mixture in the method for preparing a hydrophobic aerogel provided in any one of the above embodiments;

[0056] S200: mixing a prepolymer mixture with a matrix, and reacting the prepolymer mixture to obtain a prepolymer wet gel;

[0057] S300: Drying the prepolymer wet gel.

[0058] In step S100, the method for preparing the prepolymer mixture is the same as the prepolymer mixture involved in the method for preparing the hydrophobic aerogel provided in the above embodiment.

[0059] The substrate may include fiber felt, metal, ceramic, or organic polymer, etc. In some embodiments, the substrate includes fiber felt, see Figure 7 , step S200 includes:

[0060] S201: directly forming the prepolymer mixture on the fiber mat, or placing the prepolymer mixture on the fiber mat.

[0061] In some embodiments, a prepolymer mixture obtained by mixing a precursor hydrolyzate, a hydrophobic agent, and a catalyst can be sprayed on the fiber felt; in other embodiments, the precursor hydrolyzate and the catalyst can be first combined with the fiber felt, and then the hydrophobic agent can be sprayed on the fiber felt, but the embodiments of the present application are not limited to this.

[0062] S202: gelling the prepolymer mixture on the fiber felt to obtain a wet gel / fiber felt composite material.

[0063] Optionally, see Figure 7 , step S300 includes:

[0064] S301: Drying the wet gel on the fiber felt to obtain a hydrophobic aerogel / fiber felt composite material.

[0065] The above-mentioned embodiments of the present application are intuitively described below according to specific examples and comparative examples. Since the performance of the hydrophobic aerogel is not easy to test alone, a hydrophobic aerogel composite material is used for testing when the performance of the hydrophobic aerogel is characterized. It can be understood that since the matrix (e.g., fiber felt) used in each embodiment is the same, the performance and performance change trend characterized by the hydrophobic aerogel composite material can also reflect the performance and performance change trend of the hydrophobic aerogel. Among them, Examples 1-6 and Comparative Examples 1-6 studied the effect of the amount of catalyst on the hydrophobic properties of the prepared hydrophobic aerogel when the ambient temperature during the gelation of the prepolymer mixture was 35°C, and Examples 7-12 and Comparative Examples 7-12 studied the effect of the ambient temperature during the gelation of the prepolymer mixture on the hydrophobic properties of the prepared hydrophobic aerogel composite material when the mass ratio of the catalyst to the prepolymer mixture was 4 / 1000.

[0066] Example 1

[0067] In Example 1 of the present application, a hydrophobic aerogel composite material is prepared according to the above steps S100-S300, wherein the ambient temperature of the prepolymer mixture during gelation 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.

[0068] Example 2

[0069] The preparation methods of the hydrophobic aerogel composite materials of Example 2 and Example 1 of the present application are basically the same, except that in Example 2 of the present application, the mass ratio of the hydrophobic agent to the prepolymer mixed liquid is 25 / 1000.

[0070] Example 3

[0071] The preparation methods of the hydrophobic aerogel composite materials of Example 3 of the present application are basically the same as those of Example 1, except that in Example 3 of the present application, the mass ratio of the hydrophobic agent to the prepolymer mixture is 31.25 / 1000.

[0072] Example 4

[0073] The preparation methods of the hydrophobic aerogel composite materials of Example 3 and Example 1 of the present application are basically the same, except that in Example 4 of the present application, the mass ratio of the hydrophobic agent to the prepolymer mixture is 37.5 / 1000.

[0074] Example 5

[0075] The preparation methods of the hydrophobic aerogel composite materials of Example 3 and Example 1 of the present application are basically the same, except that in Example 5 of the present application, the mass ratio of the hydrophobic agent to the prepolymer mixed liquid is 50 / 1000.

[0076] Example 6

[0077] The preparation methods of the hydrophobic aerogel composite materials of Example 6 of the present application are basically the same as those of Example 1, except that in Example 6 of the present application, the mass ratio of the hydrophobic agent to the prepolymer mixture is 62.5 / 1000.

[0078] Example 7

[0079] The preparation methods of the hydrophobic aerogel composite materials of Example 7 of the present application are basically the same as those of Example 1, except that in Example 7 of the present application, the mass ratio of the hydrophobic agent to the prepolymer mixture is fixed at 62.5 / 1000, and the ambient temperatures during gelation of the prepolymer mixture are 30°C, 35°C, 40°C, 45°C, and 50°C, respectively.

[0080] Example 8

[0081] The preparation methods of the hydrophobic aerogel composite materials of Example 8 and Example 7 of the present application are basically the same, except that in Example 7 of the present application, the mass ratio of the hydrophobic agent to the prepolymer mixed liquid is 25 / 1000.

[0082] Example 9

[0083] The preparation methods of the hydrophobic aerogel composite materials of Example 9 and Example 7 of the present application are basically the same, except that in Example 3 of the present application, the mass ratio of the hydrophobic agent to the prepolymer mixture is 31.25 / 1000.

[0084] Example 10

[0085] The preparation methods of the hydrophobic aerogel composite materials of Example 10 and Example 7 of the present application are basically the same, except that in Example 4 of the present application, the mass ratio of the hydrophobic agent to the prepolymer mixture is 37.5 / 1000.

[0086] Embodiment 11

[0087] The preparation methods of the hydrophobic aerogel composite materials of Example 11 and Example 7 of the present application are basically the same, except that in Example 5 of the present application, the mass ratio of the hydrophobic agent to the prepolymer mixed liquid is 50 / 1000.

[0088] Example 12

[0089] The preparation methods of the hydrophobic aerogel composite materials of Example 12 and Example 7 of the present application are basically the same, except that in Example 6 of the present application, the mass ratio of the hydrophobic agent to the prepolymer mixture is 62.5 / 1000.

[0090] Comparative Examples 1-12

[0091] The preparation method of the hydrophobic aerogel composite material of the comparative examples 1-12 of the present application is basically the same as the preparation method of the hydrophobic aerogel composite material of the examples 1-12, and corresponds one to one, the difference being that the precursor used in the examples 1-12 of the present application is a precursor hydrolyzate, and the precursor used in the comparative examples 1-12 is an unhydrolyzed precursor raw material, for example, the precursor used in the examples 1-12 of the present application is a silicon source hydrolyzate, and the precursor used in the comparative examples 1-12 is a silicon source powder.

[0092] After obtaining the hydrophobic aerogel composite materials of the above-mentioned Examples 1-12 and Comparative Examples 1-12, the hydrophobic properties of each hydrophobic aerogel composite material were further tested. The testing method was to soak each hydrophobic aerogel composite material in water for 30 minutes and then take it out, and measure the percentage of increased weight of the hydrophobic aerogel composite material after soaking. The test results obtained are shown in Tables 1-4.

[0093]

[0094]

[0095]

[0096]

[0097] It can be seen from Examples 1-6 that the more the catalyst content, the shorter the gel time, the faster the gel rate, and the more the hydrophobic agent content. The weight of the obtained hydrophobic aerogel composite material increased by about 10% after being taken out after being immersed in water for 30 minutes. The better the hydrophobic performance, considering the production cost, the use of catalyst and hydrophobic agent cannot be too high. When the hydrophobic agent is dimethyldiethoxysilane, the mass ratio of the catalyst to the prepolymer mixture is 5 / 1000-7 / 1000, and the mass ratio of the hydrophobic agent to the prepolymer mixture is 25 / 1000-62.5 / 1000; and when the hydrophobic agent is propyltriethoxysilane, the mass ratio of the catalyst to the prepolymer mixture is 5 / 1000-7 / 1000, and the mass ratio of the hydrophobic agent to the prepolymer mixture is 37.5 / 1000-62.5 / 1000, and the weight increase of the obtained hydrophobic aerogel composite material after being taken out after being immersed in water for 30 minutes is about 10% of the initial weight, and the hydrophobic property is good; when the hydrophobic agent is methyltriethoxysilane, the hydrophobicity of the obtained hydrophobic aerogel composite material is not as good as the solution using dimethyldiethoxysilane and propyltriethoxysilane.

[0098] It can be seen from Examples 7-12 that the higher the temperature, the shorter the gel time and the faster the gel rate. The weight of the obtained hydrophobic aerogel composite material increased by about 10% of the initial weight after being taken out after being immersed in water for 30 minutes. The better the hydrophobic performance, however, the higher the temperature, the higher the requirements for the reaction equipment, and the greater the energy consumption, which is not conducive to cost control. When the hydrophobic agent is dimethyldiethoxysilane, the ambient temperature of the prepolymer mixture to obtain the prepolymer wet gel by reaction is 10°C-70°C, and the mass ratio of the hydrophobic agent to the prepolymer mixture is 25 / 1000-62.5 / 1000; and when the catalyst is propyltriethoxysilane, the ambient temperature of the prepolymer mixture to obtain the prepolymer wet gel by reaction is 10°C-70°C, and the mass ratio of the hydrophobic agent to the prepolymer mixture is 37.5 / 1000-62.5 / 1000. The obtained hydrophobic aerogel composite material has an increased weight of about 10% of the initial weight after being taken out after being immersed in water for 30 minutes, and has good hydrophobic performance.

[0099] It can be seen from Examples 1-12 and Comparative Examples 1-12 that when the hydrophobic agent is dimethyldiethoxysilane, under the condition that other materials are the same and the preparation conditions are the same, the hydrophobic aerogel composite material prepared by the precursor hydrolyzate (silicon source hydrolyzate) in the examples of the present application is substantially improved in hydrophobic performance compared with the hydrophobic aerogel composite material prepared by using an unhydrolyzed precursor; when the hydrophobic agent is methyltriethoxysilane, the hydrophobic aerogel composite material prepared by the silicon source hydrolyzate in the examples of the present application is substantially improved in hydrophobic performance compared with the hydrophobic aerogel composite material prepared by using an unhydrolyzed silicon source; when the catalyst is propyltriethoxysilane, the hydrophobic aerogel composite material prepared by the silicon source hydrolyzate in the examples of the present application is substantially improved in hydrophobic performance compared with the hydrophobic aerogel composite material prepared by using an unhydrolyzed silicon source; When ethoxysilane is used, under the conditions that 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 37.5 / 1000-62.5 / 1000, and the ambient temperature for the reaction of the prepolymer mixture to obtain the prepolymer wet gel is 10°C-70°C, and the mass ratio of the hydrophobic agent to the prepolymer mixture is 37.5 / 1000-62.5 / 1000, the hydrophobic performance of the hydrophobic aerogel composite material prepared by the silicon source hydrolyzate in the embodiment of the present application is substantially greatly improved compared with the hydrophobic aerogel composite material prepared by using the unhydrolyzed silicon source.

[0100] The present application also studies the thermal insulation properties of the hydrophobic aerogel composite material. Specifically, the hydrophobic aerogel composite material prepared by the method provided in Examples 6-1 and 6-3 in Example 6 of the present application and Examples 12-1 and 12-3 in Example 12 was tested, and the test results are shown in Table 5.

[0101]

[0102] It can be seen from Table 5 that when the hydrophobic agent is dimethyldiethoxysilane, the thermal conductivity of the hydrophobic aerogel composite material provided in the embodiment of the present application is greater than 0.018W / (m*K) and less than 0.022W / (m*K); when the hydrophobic agent is propyltriethoxysilane, the thermal conductivity of the hydrophobic aerogel composite material provided in the embodiment of the present application is greater than 0.018W / (m*K) and less than 0.024W / (m*K). It can be seen that the thermal conductivity of the hydrophobic aerogel composite material prepared by the method provided in the embodiment of the present application is small. This is because the hydrophobic aerogel composite material in the present application is a porous network structure with nanoscale and / or micron-scale pores, which makes the heat conduction path in the solid skeleton extremely complex and long, greatly reducing the efficiency of heat conduction through the solid skeleton, and because the porosity in the hydrophobic aerogel composite material is high, the gas in the pores is mainly air or other gases with low thermal conductivity, and the conduction of heat in the gas is relatively difficult, further reducing the thermal conductivity of the gas.

[0103] Based on the excellent hydrophobicity and / or thermal insulation properties of the hydrophobic aerogel and the hydrophobic aerogel composite provided in the present application, the hydrophobic aerogel composite provided in the present application can be applied in the field of battery devices, for example, as a thermal insulation member between battery cells.

[0104] See also Figure 8 Some embodiments of the present application provide a battery device 10, including a box 11, a plurality of battery cells 12 and a thermal insulation member 13, wherein the plurality of battery cells 12 are arranged in the box 11, and the thermal insulation member 13 is arranged between the plurality of battery cells 12, wherein the material of the thermal insulation member 13 is the hydrophobic aerogel provided in any of the above embodiments.

[0105] The material of the thermal insulation member 13 of the present application is the hydrophobic aerogel provided in the embodiment of the present application. Since the hydrophobic aerogel has excellent thermal insulation properties, it can reduce the risk of heat being transferred to adjacent battery cells 12 after thermal runaway occurs in one battery cell 12 .

[0106] The technical solution provided in the embodiment of the present application omits the step of hydrolyzing the precursor by directly using a precursor hydrolyzate. When reacting with the hydrophobic agent, the hydrophobic agent will no longer participate in the hydrolysis of the precursor, but will participate more in the modification reaction, thereby reducing the consumption of the hydrophobic agent. In addition, the present application does not require the provision of separate hydrophobic modification operation steps and devices. Therefore, the preparation method of the hydrophobic aerogel provided in the present application is simpler to operate, more environmentally friendly, and more cost-effective.

[0107] The above are only implementation methods of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for preparing a hydrophobic aerogel, characterized in that: include: Mixing a precursor hydrolyzate, a catalyst and a hydrophobic agent to form a prepolymer mixture, and reacting the prepolymer mixture to obtain a prepolymer wet gel; and The prepolymer wet gel is dried.

2. The method for preparing the hydrophobic aerogel according to claim 1, characterized in that: The step of mixing the precursor hydrolyzate, the catalyst and the hydrophobic agent to form a prepolymer mixture, and reacting the prepolymer mixture to obtain a prepolymer wet gel comprises: mixing the precursor hydrolyzate, the catalyst and the hydrophobic agent simultaneously; or Firstly, the precursor hydrolyzate and the catalyst are mixed, and then the hydrophobic agent is added; or Firstly, the precursor hydrolyzate and the hydrophobic agent are mixed, and then the catalyst is added; or The catalyst and the hydrophobic agent are mixed and then added into the precursor hydrolyzate.

3. The method for preparing the hydrophobic aerogel according to claim 1, characterized in that: In the step of mixing the precursor hydrolyzate, the catalyst and the hydrophobic agent to form a prepolymer mixture, and reacting the prepolymer mixture to obtain a prepolymer wet gel, the gelling time is 1-7 minutes.

4. The method for preparing the hydrophobic aerogel according to claim 3, characterized in that: In the step of mixing the precursor hydrolyzate, the catalyst and the hydrophobic agent to form a prepolymer mixture, and reacting the prepolymer mixture to obtain a prepolymer wet gel, the gelling time is 2-3 minutes.

5. The method for preparing the hydrophobic aerogel according to claim 1, characterized in that: The environment temperature for the reaction of the prepolymer mixed liquid to obtain the prepolymer wet gel is 10°C-70°C.

6. The method for preparing the hydrophobic aerogel according to claim 5, characterized in that: The environment temperature for the reaction of the prepolymer mixed liquid to obtain the prepolymer wet gel is 30°C-50°C.

7. The method for preparing the hydrophobic aerogel according to claim 1, characterized in that: In the step of mixing the precursor hydrolyzate, the catalyst and the 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 3 / 1000-7 / 1000.

8. The method for preparing the hydrophobic aerogel according to claim 1, characterized in that: In the step of mixing the precursor hydrolyzate, the catalyst and the 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 12.5 / 1000-125 / 1000.

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

10. The method for preparing the hydrophobic aerogel according to claim 1, characterized in that: 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 mixed liquid is 25 / 1000-62.5 / 1000.

11. The method for preparing the hydrophobic aerogel according to claim 1, characterized in that: 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 mixed liquid is 37.5 / 1000-62.5 / 1000.

12. The method for preparing the hydrophobic aerogel according to claim 1, characterized in that: The hydrophobic agent is dimethyldiethoxysilane; The environment temperature of the prepolymer mixed solution to obtain the prepolymer wet gel is 10°C-70°C; The mass ratio of the hydrophobic agent to the prepolymer mixed liquid is 25 / 1000-62.5 / 1000.

13. The method for preparing the hydrophobic aerogel according to claim 1, characterized in that: The catalyst is propyltriethoxysilane; The environment temperature of the prepolymer mixed solution to obtain the prepolymer wet gel is 10°C-70°C; The mass ratio of the hydrophobic agent to the prepolymer mixed liquid is 37.5 / 1000-62.5 / 1000.

14. A method for preparing a hydrophobic aerogel composite material, characterized in that: include: Providing a prepolymer mixed solution in the method for preparing the hydrophobic aerogel provided in any one of claims 1 to 13; The prepolymer mixture is mixed with a 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, characterized in that: The matrix includes a fiber mat, and the steps of mixing the prepolymer mixture with the matrix and reacting the prepolymer mixture to obtain a prepolymer wet gel include: forming the prepolymer mixture directly on the fiber mat, or placing the prepolymer mixture on the fiber mat; and causing the prepolymer mixture on the fiber mat to gel to obtain a wet gel / fiber mat composite material; The step of drying the wet gel comprises: drying the wet gel on the fiber felt to obtain a hydrophobic aerogel / fiber felt composite material.

16. A hydrophobic aerogel composite material, characterized in that: The hydrophobic aerogel is a hydrophobic aerogel composite material prepared by the method for preparing a hydrophobic aerogel composite material according to claim 14 or 15; Wherein, after the hydrophobic aerogel composite material is taken out after being immersed in water for 30 minutes, the increased weight is less than or equal to 10% of the initial weight.

17. The hydrophobic aerogel composite material according to claim 16, characterized in that: 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; A plurality of battery cells are arranged in the box; and A heat insulating member, disposed between the plurality of battery cells; It is characterized in that the material of the thermal insulation element is the hydrophobic aerogel composite material as described in claim 14 or 15.

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