A starch-enhanced carbon aerogel and a preparation method thereof

Abstract

The present invention relates to a starch-enhanced carbon aerogel and a preparation method thereof. The method comprises: 1) mixing starch and water, stirring, and heating to obtain gelatinized starch; 2) mixing resorcinol, formaldehyde, and sodium carbonate to obtain mixture A; mixing the mixture A with the gelatinized starch, stirring, and first aging for 1 day to obtain mixture B; 3) adding a complexing agent to the mixture B, and second aging to obtain a wet gel; the mass ratio of the added complexing agent to the starch is 1:40-60; 4) performing solvent replacement on the wet gel, and then drying and carbonizing to obtain a carbon aerogel. The present invention needs to control the time of adding the complexing agent when adding the complexing agent, and needs to add the complexing agent after the gelatinized starch is mixed with the mixture and aged for one day, so that the complexing reaction and the phenolic gelation reaction can be carried out simultaneously, thereby achieving the purpose of introducing a long-chain starch reinforcement into the carbon aerogel and improving the strength of the carbon aerogel.

Description

Technical Field

[0001] The invention belongs to the technical field of carbon aerogel preparation, and in particular relates to starch-reinforced carbon aerogel and a preparation method thereof. Background Art

[0002] Carbon aerogel has a nano-continuous porous network structure and a high specific surface area and porosity. Therefore, carbon aerogel has a low thermal conductivity and has a wide range of applications in many fields.

[0003] At present, carbon aerogels are mainly divided into two types. One is pure carbon aerogel, which has low strength and is brittle, limiting its application. The other is carbon aerogels with reinforcing fibers introduced into them. The addition of reinforcing fibers can effectively improve the strength of carbon aerogels and expand the scope of use of carbon aerogels. Generally, reinforcing fibers are mainly carbon fibers, alumina or silica fibers, etc. The addition of reinforcing fibers can improve the strength of carbon aerogels to a certain extent, but it will also bring certain side effects. For example, when reinforcing fibers are alumina or silica fibers, alumina or silica fibers are prone to carbon thermal reduction reaction with carbon at high temperatures, resulting in the carbon aerogel being unable to be used in high temperature environments. When reinforcing fibers are carbon fibers, carbonization treatment is required during the preparation of carbon aerogels. During the carbonization process, the shrinkage of carbon aerogels and carbon fibers does not match, and large gaps are easily formed, resulting in high thermal conductivity and poor thermal insulation performance of the composite material. Summary of the invention

[0004] The main purpose of the present invention is to provide a starch-reinforced carbon aerogel and a preparation method thereof, and the technical problem to be solved is to provide a starch-reinforced carbon aerogel with high strength, low thermal conductivity and excellent elastic modulus.

[0005] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. According to a method for preparing starch-enhanced carbon aerogel proposed in the present invention, the method comprises:

[0006] 1) mixing starch and water, stirring, and heating to obtain gelatinized starch;

[0007] 2) mixing resorcinol, formaldehyde and sodium carbonate to obtain a mixture A; mixing the mixture A with the gelatinized starch, stirring, and aging for a first time for 1 day to obtain a mixture B;

[0008] 3) adding a complexing agent to the mixture B, performing a second aging to obtain a wet gel; the mass ratio of the added complexing agent to the starch is 1:40-60;

[0009] 4) The wet gel is subjected to solvent replacement, and then dried and carbonized to obtain carbon aerogel.

[0010] Preferably, in the aforementioned preparation method, the complexing agent is selected from at least one of a water-soluble salt of calcium, a water-soluble salt of magnesium, a water-soluble salt of iron, a water-soluble salt of aluminum and a water-soluble salt of barium.

[0011] Preferably, in the aforementioned preparation method, in step 1), the mass ratio of starch to water is 1-20:100, and the heating temperature is 100-120°C.

[0012] Preferably, in the aforementioned preparation method, the mass ratio of starch to water is 2 to 8:100.

[0013] Preferably, in the aforementioned preparation method, the molar ratio of water to resorcinol is 150-250:1; and the first aging temperature is 23-26°C.

[0014] Preferably, in the aforementioned preparation method, the second aging is first aging at 60-70° C. for 1-2 days, and then aging at 80-100° C. for 3-4 days.

[0015] Preferably, in the aforementioned preparation method, in step 4), the solvent replacement step is as follows: the wet gel is completely immersed in ethanol, the ethanol is replaced every 12-24 hours, and this is repeated 3 to 6 times.

[0016] Preferably, in the aforementioned preparation method, in step 4), the carbonization process is: heating to 900-1100°C at 2-5°C / min, keeping warm for 1-2h, then cooling to 600°C at 2-4°C / min, and finally cooling to 23-25°C with the furnace.

[0017] The purpose of the present invention and the technical problem solved by the present invention are also achieved by the following technical solutions: According to a starch-enhanced carbon aerogel proposed by the present invention, the carbon aerogel includes long-chain starch.

[0018] Preferably, the aforementioned carbon aerogel is prepared by the aforementioned method for preparing starch-enhanced carbon aerogel.

[0019] By means of the above technical solution, the starch-enhanced carbon aerogel and the preparation method thereof proposed in the present invention have at least the following advantages:

[0020] The carbon aerogel prepared by the present invention contains a long-chain starch reinforcement, and the addition of the long-chain starch reinforcement can enhance the strength of the carbon aerogel and reduce the thermal conductivity of the material. In terms of the selection of starch, the present invention selects corn starch, potato starch, wheat starch, mung bean starch, etc.

[0021] The present invention uses resorcinol and formaldehyde as raw materials, reacts under the condition of sodium carbonate as a catalyst to prepare a mixture, then mixes gelatinized starch with the mixture, and ages it for one day. During the one-day aging time, resorcinol and formaldehyde will undergo a preliminary reaction. After one day of aging, a complexing agent is added, and the added complexing agent is selected from at least one of calcium water-soluble salt, magnesium water-soluble salt, iron water-soluble salt, aluminum water-soluble salt and barium water-soluble salt. The addition of the complexing agent can complex the long-chain structure of starch, thereby improving the strength of the carbon aerogel.

[0022] The present invention needs to control the time of adding the complexing agent, that is, the gelatinized starch needs to be mixed with the mixture and added after aging for one day, at which time the resorcinol and formaldehyde have just undergone a phenolic gelation reaction, and after the complexing agent is added, the starch molecules also begin a complexation reaction, so that the complexation reaction and the phenolic gelation reaction can proceed simultaneously, thereby achieving the purpose of introducing a long-chain starch reinforcement into the carbon aerogel and improving the strength of the carbon aerogel.

[0023] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows. DETAILED DESCRIPTION

[0024] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of a starch-enhanced carbon aerogel and its preparation method according to the present invention, its specific implementation, structure, characteristics and effects in combination with the preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0025] The present invention provides a method for preparing starch-reinforced carbon aerogel, the method comprising:

[0026] 1) mixing starch and water, stirring, and heating to obtain gelatinized starch;

[0027] 2) mixing resorcinol, formaldehyde and sodium carbonate to obtain a mixture A; mixing the mixture A with the gelatinized starch, stirring, and aging for a first time for 1 day to obtain a mixture B;

[0028] 3) adding a complexing agent to the mixture B, performing a second aging to obtain a wet gel; the mass ratio of the added complexing agent to the starch is 1:40-60;

[0029] 4) The wet gel is subjected to solvent replacement, and then dried and carbonized to obtain carbon aerogel.

[0030] The complexing agent is added after the gelatinized starch and the mixture are mixed and aged for one day. At this time, resorcinol and formaldehyde have just undergone phenolic gelation reaction. After the complexing agent is added at this time, the starch molecules also begin complexation reaction, so that the complexation reaction and the phenolic gelation reaction can be carried out simultaneously, thereby realizing the introduction of long-chain starch reinforcement into the carbon aerogel. The introduction of the long-chain starch reinforcement can ensure that the carbonization of the reinforcement is consistent with the carbonization shrinkage of phenolic at the molecular level, thereby avoiding the generation of large pores and gaps in the carbonization process of the carbon aerogel, and avoiding the high thermal conductivity and poor thermal insulation performance of the composite material.

[0031] When resorcinol and formaldehyde undergo phenolic gelation reaction, the required solvent is an aqueous solution. The present invention utilizes water in gelatinized starch as the solvent for the phenolic gelation reaction, which can effectively control the water content in the reaction system and save production costs.

[0032] Preferably, in the aforementioned preparation method, the complexing agent is selected from at least one of a water-soluble salt of calcium, a water-soluble salt of magnesium, a water-soluble salt of iron, a water-soluble salt of aluminum and a water-soluble salt of barium.

[0033] The complexing agents added in the present invention are all water-soluble salts. The addition of the complexing agents can complex the long-chain structure of starch. Introducing the long-chain starch reinforcement into the carbon aerogel can improve the strength of the carbon aerogel.

[0034] Preferably, in the aforementioned preparation method, in step 1), the mass ratio of starch to water is 1-20:100, and the heating temperature is 100-120°C.

[0035] Preferably, in the aforementioned preparation method, the mass ratio of starch to water is 2 to 8:100.

[0036] Preferably, in the aforementioned preparation method, in step 2), the molar ratio of resorcinol to formaldehyde is 1:1.5-2.5; the molar ratio of resorcinol to sodium carbonate is 350-450:1; the molar ratio of resorcinol to water is 1:150-250; the molar ratio of water to resorcinol is 150-250:1; and the first aging temperature is 23-26°C.

[0037] The amount of gelatinized starch added is proportional to the strength of the carbon aerogel. The more gelatinized starch is added, the higher the strength of the carbon aerogel is. The present invention can control the amount of gelatinized starch and mixture A added by controlling the molar ratio of water to resorcinol to be 150-250:1 and the mass ratio of starch to water to be 1-20:100. If the amount of starch added is too much, the thermal conductivity of the material is too high. If the amount of starch added is too little, the strength of the material is low and it is difficult to achieve the enhancement effect.

[0038] Preferably, in the aforementioned preparation method, the second aging is first aging at 60-70° C. for 1-2 days, and then aging at 80-100° C. for 3-4 days.

[0039] Preferably, in the aforementioned preparation method, in step 4), the solvent replacement step is as follows: the wet gel is completely immersed in ethanol, the ethanol is replaced every 12-24 hours, and this is repeated 3 to 6 times.

[0040] Preferably, in the aforementioned preparation method, in step 4), the carbonization process is: heating to 900-1100°C at 2-5°C / min, keeping warm for 1-2h, then cooling to 600°C at 2-4°C / min, and finally cooling to 23-25°C with the furnace.

[0041] Preferably, in the aforementioned preparation method, the starch is one or more of corn starch, potato starch, wheat starch and mung bean starch.

[0042] The present invention also provides a starch-reinforced carbon aerogel, wherein the carbon aerogel comprises long-chain starch.

[0043] Preferably, the aforementioned carbon aerogel is prepared by the aforementioned method for preparing starch-enhanced carbon aerogel.

[0044] The present invention will be further described below in conjunction with specific embodiments, but this should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by technicians in this field based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0045] Unless otherwise specified, the materials, reagents, etc. involved below are all commercially available products well known to those skilled in the art; unless otherwise specified, the methods described are all methods well known in the art. Unless otherwise defined, the technical terms or scientific terms used should have the common meanings understood by ordinary technicians in the field to which the present invention belongs.

[0046] Example 1

[0047] 1) Mix 2 g corn starch and 100 g water, stir evenly, heat to 100 ° C and stir for 2 min to obtain gelatinized starch;

[0048] 2) mixing resorcinol, formaldehyde and sodium carbonate to obtain a mixture A; the molar ratio of the resorcinol to formaldehyde is 1:2; the molar ratio of the resorcinol to sodium carbonate is 380:1; mixing the mixture A with the gelatinized starch, stirring, and aging in an oven at 25° C. for 1 day to obtain a mixture B; the molar ratio of the resorcinol to water is 1:220;

[0049] 3) adding a complexing agent to the mixture B, placing it in an oven at 60° C. for aging for 1 day, and then placing it in an oven at 90° C. for aging for 3 days to obtain a wet gel; the mass ratio of the added complexing agent to the starch is 1:50;

[0050] 4) The wet gel was completely immersed in ethanol, and the ethanol was replaced every 18 hours, and repeated 4 times.

[0051] Then supercritical drying was carried out with a drying pressure of 10 MPa and a drying temperature of 45°C. After drying, the temperature was raised to 900°C at a rate of 3°C / min, kept for 2 hours, then cooled to 600°C at a rate of 3°C / min, and finally cooled to 24°C to obtain starch-reinforced carbon aerogel.

[0052] Example 2

[0053] 1) Mix 10 g corn starch and 100 g water, stir evenly, heat to 100 ° C and stir for 2 min to obtain gelatinized starch;

[0054] 2) mixing resorcinol, formaldehyde and sodium carbonate to obtain a mixture A; the molar ratio of the resorcinol to formaldehyde is 1:2; the molar ratio of the resorcinol to sodium carbonate is 380:1; mixing the mixture A with the gelatinized starch, stirring, and aging in an oven at 25° C. for 1 day to obtain a mixture B; the molar ratio of the resorcinol to water is 1:220;

[0055] 3) adding a complexing agent to the mixture B, placing it in an oven at 60° C. for aging for 1 day, and then placing it in an oven at 90° C. for aging for 3 days to obtain a wet gel; the mass ratio of the added complexing agent to the starch is 1:50;

[0056] 4) The wet gel was completely immersed in ethanol, and the ethanol was replaced every 18 hours, and repeated 4 times.

[0057] Then supercritical drying was carried out with a drying pressure of 10 MPa and a drying temperature of 45°C. After drying, the temperature was raised to 900°C at a rate of 3°C / min, kept for 2 hours, then cooled to 600°C at a rate of 3°C / min, and finally cooled to 24°C to obtain starch-reinforced carbon aerogel.

[0058] Example 3

[0059] 1) Mix 20 g corn starch and 100 g water, stir evenly, heat to 100 ° C and stir for 2 min to obtain gelatinized starch;

[0060] 2) mixing resorcinol, formaldehyde and sodium carbonate to obtain a mixture A; the molar ratio of resorcinol to formaldehyde is 1:2; the molar ratio of resorcinol to sodium carbonate is 380:1; mixing the mixture A with the gelatinized starch, stirring, and aging in an oven at 26° C. for 1 day to obtain a mixture B; the molar ratio of resorcinol to water is 1:220;

[0061] 3) adding a complexing agent to the mixture B, placing it in an oven at 70° C. for aging for 1 day, and then placing it in an oven at 100° C. for aging for 3 days to obtain a wet gel; the mass ratio of the added complexing agent to the starch is 1:50;

[0062] 4) The wet gel was completely immersed in ethanol, and the ethanol was replaced every 18 hours, and repeated 6 times.

[0063] Then supercritical drying was carried out with a drying pressure of 10 MPa and a drying temperature of 45°C. After drying, the temperature was raised to 1100°C at 5°C / min, kept for 2h, then cooled to 600°C at 4°C / min, and finally cooled to 25°C to obtain starch-reinforced carbon aerogel.

[0064] Example 4

[0065] 1) Mix 2 g potato starch and 100 g water, stir evenly, heat to 100 ° C and stir for 2 min to obtain gelatinized starch;

[0066] 2) mixing resorcinol, formaldehyde and sodium carbonate to obtain a mixture A; the molar ratio of the resorcinol to formaldehyde is 1:2; the molar ratio of the resorcinol to sodium carbonate is 380:1; mixing the mixture A with the gelatinized starch, stirring, and aging in an oven at 25° C. for 1 day to obtain a mixture B; the molar ratio of the resorcinol to water is 1:220;

[0067] 3) adding a complexing agent to the mixture B, placing it in an oven at 60° C. for aging for 1 day, and then placing it in an oven at 90° C. for aging for 3 days to obtain a wet gel; the mass ratio of the added complexing agent to the starch is 1:50;

[0068] 4) The wet gel was completely immersed in ethanol, and the ethanol was replaced every 18 hours, and repeated 4 times.

[0069] Then supercritical drying was carried out with a drying pressure of 10 MPa and a drying temperature of 45°C. After drying, the temperature was raised to 900°C at a rate of 3°C / min, kept for 2 hours, then cooled to 600°C at a rate of 3°C / min, and finally cooled to 24°C to obtain starch-reinforced carbon aerogel.

[0070] Example 5

[0071] 1) Mix 2 g potato starch and 100 g water, stir evenly, heat to 120° C. and stir for 2 min to obtain gelatinized starch;

[0072] 2) mixing resorcinol, formaldehyde and sodium carbonate to obtain a mixture A; the molar ratio of resorcinol to formaldehyde is 1:2.5; the molar ratio of resorcinol to sodium carbonate is 450:1; mixing the mixture A with the gelatinized starch, stirring, and aging in an oven at 25° C. for 1 day to obtain a mixture B; the molar ratio of resorcinol to water is 1:250;

[0073] 3) adding a complexing agent to the mixture B, placing it in an oven at 70° C. for aging for 2 days, and then placing it in an oven at 100° C. for aging for 4 days to obtain a wet gel; the mass ratio of the added complexing agent to the starch is 1:60;

[0074] 4) The wet gel was completely immersed in ethanol, and the ethanol was replaced every 24 hours, and repeated 5 times.

[0075] Then supercritical drying was carried out with a drying pressure of 10 MPa and a drying temperature of 45°C. After drying, the temperature was raised to 1100°C at 5°C / min, kept for 2h, then cooled to 600°C at 4°C / min, and finally cooled to 25°C to obtain starch-reinforced carbon aerogel.

[0076] Example 6

[0077] 1) Mix 1g wheat starch and 100g water, stir evenly, heat to 120°C and stir for 2min to obtain gelatinized starch;

[0078] 2) mixing resorcinol, formaldehyde and sodium carbonate to obtain a mixture A; the molar ratio of resorcinol to formaldehyde is 1:1.5; the molar ratio of resorcinol to sodium carbonate is 350:1; mixing the mixture A with the gelatinized starch, stirring, and aging in an oven at 23° C. for 1 day to obtain a mixture B; the molar ratio of resorcinol to water is 1:150;

[0079] 3) adding a complexing agent to the mixture B, placing it in an oven at 60° C. for aging for 1 day, and then placing it in an oven at 80° C. for aging for 3 days to obtain a wet gel; the mass ratio of the added complexing agent to the starch is 1:40;

[0080] 4) The wet gel was completely immersed in ethanol, and the ethanol was replaced every 12 hours, and repeated 3 times.

[0081] Then supercritical drying was carried out with a drying pressure of 10 MPa and a drying temperature of 45°C. After drying, the temperature was raised to 900°C at 2°C / min, kept for 1 hour, then cooled to 600°C at 2°C / min, and finally cooled to 23°C to obtain starch-reinforced carbon aerogel.

[0082] Comparative Example 1

[0083] 1) Mix 2 g corn starch and 100 g water, stir evenly, heat to 100 ° C and stir for 2 min to obtain gelatinized starch;

[0084] 2) mixing resorcinol, formaldehyde and sodium carbonate to obtain a mixture A; the molar ratio of the resorcinol to formaldehyde is 1:2; the molar ratio of the resorcinol to sodium carbonate is 380:1; mixing the mixture A with the gelatinized starch, stirring, and aging in an oven at 25° C. for 1 day to obtain a mixture B; the molar ratio of the resorcinol to water is 1:220;

[0085] 3) placing the mixture B in an oven at 60° C. for aging for 1 day, and then placing it in an oven at 90° C. for aging for 3 days to obtain a wet gel;

[0086] 4) The wet gel was completely immersed in ethanol, and the ethanol was replaced every 18 hours, and repeated 4 times.

[0087] Then supercritical drying was carried out with a drying pressure of 10 MPa and a drying temperature of 45°C. After drying, the temperature was raised to 900°C at a rate of 3°C / min, kept for 2 hours, then cooled to 600°C at a rate of 3°C / min, and finally cooled to 24°C to obtain starch-reinforced carbon aerogel.

[0088] Comparative Example 2

[0089] 1) resorcinol, formaldehyde, sodium carbonate and water are mixed, aged at 25°C for 1 day, placed in an oven at 60°C for 1 day, and then placed in an oven at 90°C for 3 days to obtain a wet gel;

[0090] 2) The wet gel is completely immersed in ethanol, the ethanol is replaced every 12 hours, and the process is repeated 3 times, followed by supercritical drying at a drying pressure of 10 MPa and a drying temperature of 45°C. After drying, the temperature is increased to 900°C at a rate of 3°C / min, kept at this temperature for 2 hours, then decreased to 600°C at a rate of 2°C / min, and finally cooled to 23°C to obtain a low thermal conductivity composite structure carbon aerogel.

[0091] The thermal conductivity of Examples 1 to 4 and Comparative Examples 1 to 2 was tested, and the results are shown in the following table:

[0092] Table 1

[0093]

[0094]

[0095] The elastic modulus tests were performed on Examples 1 to 4 and Comparative Examples 1 to 2, and the results are shown in the following table:

[0096] Table 2

[0097]

[0098] Compared with Example 1, no complexing agent is added to Comparative Example 1. It can be seen from the data in Table 1 that the thermal conductivity of Example 1 at 2000°C is less than that of Comparative Example 1 at 2000°C. It can be seen from the data in Table 2 that the elastic modulus of Example 1 is greater than that of Comparative Example 1, indicating that the addition of a complexing agent can introduce starch reinforcement into the carbon aerogel, and the introduction of starch reinforcement can increase the elastic modulus of the carbon aerogel. By comparing Example 1 and Example 2, it can be seen that the higher the amount of starch added, the higher the strength of the prepared carbon aerogel, and correspondingly, the thermal conductivity of the material also increases with the increase of starch content.

[0099] Compared with Example 1 and Example 4, Example 1 uses corn starch and Example 4 uses potato starch. By comparing the data in Table 1 and Table 2, it can be concluded that the carbon aerogel prepared with potato starch as raw material has higher strength than the carbon aerogel prepared with corn starch as raw material. The reason is that compared with corn starch, potato starch is straight-chain starch with a smaller molecular weight, while potato starch contains both straight-chain starch and amylopectin, and amylopectin accounts for a larger proportion and has a larger molecular weight. This is the reason why the various properties of Example 4 are better than those of Example 1.

[0100] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0101] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for preparing starch-enhanced carbon aerogel, characterized in that: The method comprises: 1) Mixing starch and water, stirring, and heating to obtain gelatinized starch; 2) mixing resorcinol, formaldehyde and sodium carbonate to obtain a mixture A; mixing the mixture A with the gelatinized starch, stirring, and aging for a first time for 1 day to obtain a mixture B; 3) adding a complexing agent to the mixture B, performing a second aging to obtain a wet gel; the mass ratio of the added complexing agent to the starch is 1:40-60; 4) The wet gel is subjected to solvent replacement, and then dried and carbonized to obtain carbon aerogel.

2. The preparation method according to claim 1, characterized in that: The complexing agent is selected from at least one of a calcium water-soluble salt, a magnesium water-soluble salt, an iron water-soluble salt, an aluminum water-soluble salt and a barium water-soluble salt.

3. The preparation method according to claim 1, characterized in that: In step 1), the mass ratio of starch to water is 1-20:100, and the heating temperature is 100-120°C.

4. The preparation method according to claim 3, characterized in that: The mass ratio of starch to water is 2 to 8:

100.

5. The preparation method according to claim 3 or 4, characterized in that: The molar ratio of water to resorcinol is 150-250:1; and the first aging temperature is 23-26°C.

6. The preparation method according to claim 1, characterized in that: The second aging is first aging at 60-70° C. for 1-2 days, and then aging at 80-100° C. for 3-4 days.

7. The preparation method according to claim 1, characterized in that: In step 4), the solvent replacement step is as follows: the wet gel is completely immersed in ethanol, the ethanol is replaced every 12-24 hours, and this is repeated 3 to 6 times.

8. The preparation method according to claim 1, characterized in that: In step 4), the carbonization process is as follows: heating to 900-1100°C at 2-5°C / min, keeping the temperature for 1-2h, cooling to 600°C at 2-4°C / min, and finally cooling to 23-25°C with the furnace.

9. A starch-enhanced carbon aerogel, characterized in that: The starch-enhanced carbon aerogel comprises long-chain starch; the long-chain starch is dispersed in the carbon aerogel in a complexed form; The carbon aerogel is prepared by the method for preparing the starch-enhanced carbon aerogel according to any one of claims 1 to 8.

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