THERMAL CONTROL MEMBERS INCLUDING WET GEL BLANKETS - Patent application

Abstract

The present invention relates to a thermal control element including a wet gel blanket and a battery including the same.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0050758, filed on April 18, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a thermal control element including a wet gel blanket and a battery including the same. [Background technology]

[0003] There is a need in the electronics, industrial, and automotive technologies for suitable insulation that reliably controls heat from heat-generating parts in small spaces, providing product safety and preventing fire spread. Insulation sheets with excellent properties when compressed are useful, for example, as separators in lithium-ion battery modules.

[0004] More specifically, various insulating materials, including aerogel, are being used to prevent fires caused by thermal runaway in batteries in electric vehicles and ships. However, insulating function alone is not enough to fundamentally prevent fires. In particular, due to the limited space available inside batteries where thermal control components can be applied, it is difficult to ensure the necessary insulating thickness to fundamentally block fires, and the only effect is to delay the spread of the fire as much as possible.

[0005] Electronic products such as laptops, OLEDs, and TVs have hot spots due to heat sources, which can partially dissipate heat on the device surface, reducing the perceived quality felt by consumers. Furthermore, if a simple insulation material is used and the heat is not properly dispersed to the outside, excessive heat buildup can cause system failure, shorten the product's lifespan, or in severe cases, cause an explosion or fire. To address these heat-related issues, various insulation materials have been applied, but an optimal insulation material that is thin and has excellent insulation performance has yet to be developed, and various research and technological development efforts are currently underway.

[0006] To solve these conventional problems, some applications have focused on aerogel, which is attracting attention as a highly efficient heat insulating material. Aerogel is a highly porous material composed of nanoparticles, and has a high porosity, specific surface area, and low thermal conductivity. It is a material that has attracted attention as a highly efficient heat insulating material, soundproofing material, and other applications.

[0007] However, because such aerogels have very low mechanical strength due to their porous structure, they have been used to manufacture aerogel composites in which aerogel is impregnated and bonded to conventional insulating fibers, such as inorganic or organic fibers. However, the adhesion between the fibers and the aerogel in such aerogel composites is weak, and aerogel particles separate during processing such as cutting and bending, resulting in dust generation and reduced durability. This can cause damage to the equipment when used as an insulating material for electronic products, etc.

[0008] Thus, the reduction in battery capacity and the increase in size of battery modules and battery packs are not problems, and there is a strong need to develop materials that can prevent flames caused by ignition and explosion of battery modules and battery packs from spreading to adjacent battery modules. Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to provide a thermal control element that contains a wet gel blanket with a moisture content of 50% by weight or more, thereby effectively realizing heat insulation and fire suppression performance. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention provides a thermal control element, a battery including the thermal control element, and a method for manufacturing the thermal control element. (1) The present invention provides a thermal control element comprising a wet gel blanket having a moisture content of 50% by weight or more according to the following formula 1, and a case in which the wet gel blanket is housed.

[0011] [Formula 1] Moisture content (%)=[(ab) / a]×100

[0012] In the formula 1, a is the weight of the wet gel blanket before drying; b is the weight of the wet gel blanket after drying in a convection oven at 150°C for 24 hours.

[0013] (2) The present invention provides the thermal control element according to (1) above, wherein the wet gel blanket has a water content of 60 to 90%. (3) The present invention provides the thermal control element according to (1) or (2) above, wherein when the wet gel blanket is dried in a convection oven at 150°C for 24 hours, the average pore size of the wet gel is 1 to 50 nm.

[0014] (4) The present invention provides a thermal control element according to any one of (1) to (3), wherein the wet gel blanket has a thermal conductivity of 30 to 70 mW / mK when dried in a convection oven at 150°C for 24 hours.

[0015] (5) The present invention provides the thermal control element according to any one of (1) to (4) above, wherein the wet gel blanket is a silica wet gel blanket.

[0016] (6) The present invention provides a thermal control element according to any one of (1) to (5), wherein the wet gel blanket comprises a wet gel and a blanket substrate, and the blanket substrate is one or more selected from the group consisting of a film, a sheet, a net, a fiber, a porous material, a foam, and a nonwoven fabric. (7) The present invention provides the thermal control element according to any one of (1) to (6) above, wherein the case is a pouch.

[0017] (8) In the present invention, there is provided the thermal control element according to (7) above, wherein the pouch is made of polyethylene (PE), polyester (PET), polypropylene (PP), aluminum, or a composite material thereof. (9) The present invention provides a battery including the thermal control element according to any one of (1) to (8) above.

[0018] (10) The present invention provides a method for manufacturing a thermal control element, including the steps of: 1) preparing a silica sol; 2) preparing a case with a blanket substrate housed therein; 3) injecting the silica sol into the case to impregnate the blanket substrate with the silica sol, and sealing the case; and 4) gelling the silica sol impregnated into the blanket substrate to form a silica wet gel blanket. [Effects of the Invention]

[0019] The wet gel blanket contained in the thermal control device according to the present invention has a high internal moisture content and exhibits excellent heat absorption and fire extinguishing properties, and when used in an article, it can effectively prevent fire outbreak and spread. Furthermore, compared to aerogel blankets used as conventional thermal insulation materials, the manufacturing process is shortened, reducing manufacturing costs and improving economic efficiency. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a graph showing the pore distribution of the wet gel blankets of Examples 2 to 4 after drying. [Figure 2] FIG. 2 is a schematic diagram showing a method for evaluating flame blocking performance. DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention will now be described in more detail so that the present invention may be more easily understood. The terms and words used in the description of the present invention and the claims should not be interpreted in a limited way to their ordinary or dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of ​​the present invention, based on the principle that the inventors can appropriately define the concepts of terms in order to best describe their inventions.

[0022] The present invention will be described in detail below. The thermal control element of the present invention is characterized by including a wet gel blanket having a moisture content of 50% by weight or more according to the following formula 1, and a case in which the wet gel blanket is housed.

[0023] [Formula 1] Moisture content (%)=[(ab) / a]×100

[0024] In the formula 1, a is the weight of the wet gel blanket before drying; b is the weight of the wet gel blanket after drying in a convection oven at 150°C for 24 hours.

[0025] In the present invention, the term "wet gel" refers to a network-structured product produced by a gelation reaction of a sol, and refers to a gel containing a solvent before drying. Wet gels contain a large amount of water inside. When exposed to high temperatures, such as during thermal runaway in a battery, the water evaporates and absorbs heat, preventing the temperature on the opposite side from rising until all the water has evaporated. Once all the water has evaporated and the gel has dried, it can function as a silica gel-based blanket insulation material with nanopores.

[0026] The wet gel blanket included in the thermal control device of the present invention does not function as a heat insulator in everyday life because the wet gel is contained in a sealed case with moisture in the pores. However, when a problem such as thermal runaway occurs, the moisture inside evaporates and the blanket functions as a thermal control material.

[0027] In the present invention, the moisture content according to the above formula 1 is the moisture content contained inside the wet gel blanket, and indicates the weight ratio of moisture to the total weight including the wet gel and blanket. This can be calculated from the amount of evaporated moisture obtained by comparing the weight before drying with the weight lost after drying the wet gel blanket in a convection oven at 150°C for 24 hours according to the formula 1.

[0028] In the present invention, the water content according to the formula 1 is 50% by weight or more, and more specifically may be 60 to 90%, 50% by weight or more, 60 to 90%, 60% or more, 65% or more, 90% or less, or 85% or less.

[0029] In the present invention, the wet gel may have an average pore size of 1 to 50 nm, specifically 5 to 50 nm, more specifically 10 to 40 nm. The average pore size can be measured after drying the wet gel blanket in a convection oven at 150°C for 24 hours. The wet gel used in the present invention has the property of having a small average pore size as described above, and therefore can exhibit excellent heat insulating properties.

[0030] In the present invention, the wet gel blanket may have a thermal conductivity of 30 to 70 mW / mK, specifically 40 to 60 mW / mK. The thermal conductivity can be measured after drying the wet gel blanket in a convection oven at 150°C for 24 hours.

[0031] Due to the above-mentioned properties, the thermal control element of the present invention can suppress the spread of a fire by absorbing heat in the early stages of the fire, and thereafter act as a heat insulator, effectively blocking heat transfer to the surrounding area.

[0032] In the present invention, the wet gel blanket includes a wet gel and a blanket substrate. Here, the blanket substrate according to an embodiment of the present invention may be specifically a porous substrate. When a porous blanket substrate is used, silica sol easily penetrates into the substrate, forming a uniform wet gel inside the blanket substrate, thereby allowing the manufactured wet gel blanket to have excellent thermal insulation properties.

[0033] According to one embodiment of the present invention, the blanket substrate may be a film, sheet, net, fiber, foam, nonwoven fabric, or a laminate of two or more layers thereof. Furthermore, depending on the application, the surface may be roughened or patterned. More specifically, the blanket substrate may be a fiber that includes spaces or voids that allow for easy insertion of a wet gel, thereby further improving the insulation performance. Furthermore, the blanket substrate preferably has low thermal conductivity.

[0034] The blanket substrate may be specifically polyamide, polybenzimidazole, polyaramid, acrylic resin, phenolic resin, polyester, polyether ether ketone (PEEK), polyolefin (e.g., polyethylene, polypropylene, or copolymers thereof), cellulose, carbon, cotton, wool, hemp, nonwoven fabric, glass fiber, ceramic wool, or ceramic paper, and more specifically, the blanket substrate in the present invention may be ceramic paper.

[0035] In the present invention, the case accommodates the wet gel blanket, and the sealing shape of the wet gel blanket is not limited. The case may be, but is not limited to, a pouch type, a square type, a cylindrical type, etc. Any type that can accommodate the wet gel blanket and include it in the thermal control element in a properly sealed state is applicable.

[0036] The material of the pouch is not particularly limited, and may be a material that can effectively block moisture, such as polyethylene (PE), polyester (PET), polypropylene (PP), aluminum, or a composite material thereof.

[0037] The thermal control element of the present invention may also be included in a battery. The thermal control element of the present invention contains a large amount of water, and when thermal runaway occurs in a battery cell, the water can evaporate to absorb heat and prevent heat from being transferred to adjacent cells, effectively cooling the cell in which thermal runaway has occurred and extinguishing the fire.

[0038] In addition, after all the moisture inside has evaporated, it acts as a heat insulator, effectively blocking the transfer of uncooled heat from a cell experiencing thermal runaway to adjacent cells, thereby preventing a chain reaction of thermal runaway in battery cells and fires in electric vehicles.

[0039] Specifically, the thermal control member of the present invention is disposed on the outside of a bus bar for electrically connecting electrode leads or is applied to the inside of at least a portion of a battery pack case, thereby preventing oxygen in excess of the minimum amount required for combustion from flowing into the battery module or battery pack where ignition and flames have occurred, and preventing the heat and flames inside the battery module or battery pack from diffusing to the outside.

[0040] Specifically, when a battery module catches fire, the thermal control element of the present invention first effectively cools the cells through its heat absorption effect, and then acts as a high-performance insulating material with micropores, thereby performing both the functions of preventing the spread of fire and subsequent treatment.

[0041] The wet gel blanket of the present invention may also be a silica wet gel blanket, and for example, the thermal control element of the present invention may be produced by the following method.

[0042] Specifically, the silica wet gel blanket may be manufactured by a method including the steps of: 1) preparing a silica sol; 2) preparing a case with a blanket substrate housed therein; 3) injecting the silica sol into the case to impregnate the blanket substrate with the silica sol, and sealing the case; and 4) gelling the silica sol impregnated into the blanket substrate to form a silica wet gel blanket.

[0043] Step 1) Step 1 is a step for producing a silica sol, which may be produced by mixing a silica precursor with a gelling catalyst, and water may be further added as needed.

[0044] Specifically, the silica precursor may be a water glass solution, and the gelling catalyst in the silica sol may be added in an amount of 2.8 to 17% by weight based on the water glass in the water glass solution.

[0045] The water glass solution may be a diluted solution obtained by adding distilled water to water glass and mixing it, and the water glass may be sodium silicate (Na2SiO3), potassium silicate, or lithium silicate, which is an alkali silicate obtained by melting silicon dioxide (SiO2) and an alkali.

[0046] The water glass dispersion may contain 3 to 30 wt % silicon dioxide (SiO2). If the silicon dioxide content in the water glass dispersion is lower than this range, a gel structure cannot be properly formed. If the silicon dioxide content is higher than this range, silicon dioxide precipitates upon addition of the catalyst, forming a gel with non-uniform pores, which may reduce the pore size and specific surface area.

[0047] The gelling catalyst is not particularly limited, and may be one or more of organic acids, inorganic acids, and carbonates, such as one or more selected from the group consisting of acetic acid, oxalic acid, nitric acid, hydrochloric acid, sulfuric acid, hydrofluoric acid, and ethylene carbonate. Specifically, ethylene carbonate may be used.

[0048] The acid catalyst may be contained in an amount that causes the pH of the silica sol to be 4 to 8. If the pH of the silica sol is outside this range, the gelation in step 3) described below may not be easy or the gelation rate may be excessively slow, which may result in a decrease in processability.

[0049] Step 2) Step 2) is a step of preparing a case that contains the blanket substrate inside.

[0050] When storing the blanket substrate inside the case, for example, if the case is a pouch, the blanket substrate can be placed on one side of the pouch sealed on three sides, or films can be placed above and below the blanket substrate and the films on the three outer sides of the blanket substrate can be attached to each other to create a pouch with one side open.

[0051] Step 3) The step 3) is a step of injecting the silica sol into a case, impregnating the blanket substrate with the silica sol, and sealing the case.

[0052] Once the silica sol is completely injected into the case, the opening side of the case can be sealed to seal the case. To thoroughly remove the air inside the case, the sealing process may be performed under a low vacuum of 1 to 760 Torr. To improve the bonding between the blanket substrate and the silica sol inside the sealed case, the blanket substrate can be lightly pressed to thoroughly impregnate the silica sol. Then, the blanket substrate is pressed to a certain thickness with a certain pressure, and in step 4) described below, the thickness of the silica wet gel blanket can be made uniform.

[0053] Step 4) Step 4) is a step of gelling the silica sol impregnated into the blanket substrate to form a silica wet gel blanket.

[0054] Here, the gelation refers to a sol-gel reaction, and the "sol-gel reaction" may be a reaction that causes a network structure to be formed from silicon unit precursor materials.

[0055] Here, the network structure may refer to a planar network structure in which certain polygons having one or more types of atomic arrangements are connected, or a structure in which vertices, corners, faces, etc. of certain polyhedra are shared to form a three-dimensional skeletal structure.

[0056] In the method according to one embodiment of the present invention, after the gelation in step 4), a step of aging the produced silica wet gel blanket may be further carried out. The aging is not particularly limited, but may be carried out by leaving the mixture at a temperature of 50° C. to 90° C. for 1 hour to 24 hours, for example.

[0057] In the manufacturing method according to one embodiment of the present invention, the silica wet gel blanket is subjected to the above-mentioned aging process after production, so that the network structure of the wet gel in the silica wet gel blanket can be formed more firmly, and thus the pore characteristics can be improved.

[0058] [Example] The present invention will be described in more detail below with reference to examples. However, the following examples are for illustrative purposes only and the scope of the present invention is not limited to these examples.

[0059] Example 1 Silica sol was prepared by mixing 12 parts by weight of water glass and 75 parts by weight of water. Then, 2 parts by weight of acetic acid was added to the silica sol as a gelation catalyst to prepare a catalyzed sol. A 3mm-thick ceramic paper blanket substrate was placed in a PE / aluminum / PP pouch sealed on three sides, and the catalyzed sol was then poured into the pouch to impregnate the blanket substrate. The open side was then depressurized using a vacuum sealer and sealed by applying heat. The silica sol impregnated into the substrate was gelled inside the sealed pouch to produce a wet gel blanket.

[0060] Examples 2 to 6 A wet gel blanket was prepared in the same manner as in Example 1, except for the changes shown in Table 1 below.

[0061] Example 7 Silica sol was prepared by mixing 21 parts by weight of water glass and 67 parts by weight of water. Five parts by weight of acetic acid was then added to the silica sol as a gelation catalyst to prepare a catalyzed sol. A 2 mm thick ceramic paper blanket substrate was placed in a PE / aluminum / PP pouch sealed on three sides, and the catalyzed sol was then poured into the pouch to impregnate the blanket substrate. The open side was then depressurized using a vacuum sealer and sealed by applying heat. The silica sol impregnated into the substrate was gelled inside the sealed pouch to produce a wet gel blanket.

[0062] Example 8 Silica sol was prepared by mixing 21 parts by weight of water glass and 67 parts by weight of water. Five parts by weight of acetic acid was then added to the silica sol as a gelation catalyst to prepare a catalyzed sol. A 3mm-thick organic fiber blanket substrate was placed in a PE / aluminum / PP pouch sealed on three sides, and the catalyzed sol was then poured into the pouch to impregnate the blanket substrate. The open side was then depressurized using a vacuum sealer and sealed by applying heat. The silica sol impregnated into the substrate was gelled inside the sealed pouch to produce a wet gel blanket.

[0063] Example 9 Silica sol was prepared by mixing 20 parts by weight and 64 parts by weight of water glass and water. Five parts by weight of acetic acid was then added to the silica sol as a gelation catalyst to prepare a catalyzed sol. PET films were placed on the top and bottom of 3 mm-thick ceramic paper, and the top and bottom PET films were adhered to the three outer sides of the ceramic paper with acrylic adhesive to seal the three sides. The catalyzed sol was poured into the pouch through the open side, impregnating the blanket substrate, and the PET film on the open side was adhered with acrylic adhesive to seal the pouch. The silica sol impregnated into the substrate was gelled inside the sealed pouch to produce a wet gel blanket.

[0064] [Table 1]

[0065] Comparative Example 1 Silica sol was prepared by mixing 28 parts by weight of water glass and 54 parts by weight of water. Then, 7 parts by weight of acetic acid was added to the silica sol as a gelation catalyst to prepare a catalyzed sol. A 3 mm thick ceramic paper was placed in a mold, impregnated with the catalyzed sol, and gelation was carried out to prepare a wet gel blanket.

[0066] The wet gel blanket was dried in a convection oven at 150°C for 24 hours to remove as much moisture as possible from the gel, and a dried blanket was obtained. The dried blanket was placed in a PE / aluminum / PP pouch sealed on three sides, and the open side was vacuum sealed using a vacuum sealer and then heated to seal it.

[0067] Comparative Example 2 Tetraethyl orthosilicate (TEOS) and water were mixed in a 1:4 molar ratio, and ethanol was added in a 1:1 weight ratio to the TEOS to prepare a silica precursor solution. To promote hydrolysis, hydrochloric acid was added to the silica precursor solution until the pH was below 3, and the mixture was stirred for at least two hours to prepare a hydrated TEOS solution. A silica sol was prepared by adding ethanol in a 1:4 weight ratio to the hydrated TEOS solution. To improve thermal insulation and flame retardancy, an opacifying agent and a flame retardant were added in a weight ratio of 0.2 per 100 parts by weight of the silica sol.

[0068] The catalyzed sol was mixed with a base catalyst solution (5 wt% NaOH aqueous solution) at a volume ratio of 99:1 to produce a catalyzed sol. The catalyzed sol was impregnated into a blanket substrate for gelation. It was then aged and surface-modified in a 10 wt% TMES solution at 60°C for 16 hours. The resulting wet gel blanket was placed in a supercritical extractor, CO2 was injected, and the temperature inside the extractor was raised to 60°C for 1 hour. Supercritical drying was then performed at 60°C and 100 bar to produce a hydrophobic aerogel blanket.

[0069] Comparative Example 3 0.6 parts by weight of starch was added to 77.4 parts by weight of water and dispersed to prepare an aqueous solution, which was then absorbed into 22 parts by weight of superabsorbent polymer (SAP) to prepare a hydrogel.

[0070] The prepared hydrogel was placed in a PE / aluminum / PP pouch sealed on three sides, and the open side was vacuum sealed using a vacuum sealer, followed by heat sealing. The final thickness of the sealed pouch was 3 mm.

[0071] Experimental Example 1: Water content (wt%) The weight (a) of the wet gel blanket was measured, and then it was dried in a convection oven at 150°C for 24 hours, and the weight (b) after drying was measured. The moisture content of the wet gel blanket was calculated using the following equation 1. [Formula 1] Moisture content (%)=[(ab) / a]×100

[0072] Experimental example 2: Time (sec) for the backside temperature to reach 100°C for a 1000°C torch A sample measuring 20 cm x 20 cm was prepared and placed vertically on a table. Temperature sensors were positioned in the center of the front and back of the sample.

[0073] A torch flame using butane gas was injected at the position of the sample front temperature sensor, and the distance between the sample and the torch was adjusted so that the front temperature was 1000°C. The time it took for the sample back temperature to reach 100°C was recorded via the back temperature sensor.

[0074] [Table 2]

[0075] As shown in Table 2, when a high-temperature torch flame is sprayed onto a sample, a wet gel blanket containing excess moisture inside the gel absorbs heat until all the moisture evaporates, preventing the backside temperature from exceeding 100°C. This significantly delays the time it takes for the backside temperature to reach 100°C compared to a dry gel without moisture. In addition, the moisture in the area directly exposed to the torch flame dries quickly, functioning as a nanoporous insulator and demonstrating excellent insulation performance, resulting in a delay in the time it takes for the backside temperature to reach 100°C.

[0076] In the case of Comparative Examples 1 and 2, since the gel did not contain moisture, the back surface temperature increased very rapidly compared to the Examples. In Comparative Example 2, an aerogel blanket was manufactured, and its heat insulation performance was very excellent compared to Comparative Example 1, so the rise in the back surface temperature was relatively delayed. However, since it does not have a heat absorption function, the back surface temperature will reach 100 °C in a very short time compared to the Examples.

[0077] In the case of Comparative Example 3, unlike the Examples of the present application using silica sol, a hydrogel was used. The moisture content in the gel showed a high value similar to that of the Examples. However, different from the Examples, there was no base material for the blanket and a hard gel structure was not formed. Therefore, during the 1000 °C torch test, the moisture boiled, the seal of the pouch was damaged due to the pressure, and the phenomenon that the gel spurted out to the outside was confirmed. As a result, a large amount of the gel disappeared, showing significantly lower heat insulation performance compared to the Examples. When heat was continuously applied, after all the moisture evaporated, there was no heat insulation structure remaining inside, so the tendency for the back surface temperature to rise at a very high speed was confirmed.

[0078] Experimental Example 3: Observation of Pore Distribution The wet gel blanket was dried in a convection oven at 150 °C for 24 hours to obtain a sample in which all the moisture was removed. 0.1 g of the dried sample was placed in a BET专用 glass, connected to a pretreatment device, and pretreated at 150 °C for 12 hours while reducing the pressure from 1 to 760 Torr to remove impurities including moisture in the sample. The pore distribution of the pretreated sample was analyzed by the adsorption / desorption amount of nitrogen at a partial pressure (0.11 < p / p0 < 1) using a 3 FLEX device (Micrometrics).

[0079] As shown in Fig. 1, it was confirmed that the wet gel blankets corresponding to Examples 2 to 4 showed a very uniform and narrow pore distribution after drying, and thus it was confirmed that they had excellent heat insulation performance. In particular, since most of the pores exist in the region of 10 to 50 nm, which is the mesopore region, the heat insulation performance is even more excellent. From this, it was understood that the wet gel blanket can act as an excellent heat insulation material even after being exposed to a high temperature and all the drying of the moisture is completed.

Claims

1. A wet gel blanket having a moisture content of 50% by weight or more according to the following formula 1; a case containing the wet gel blanket. [Formula 1] Moisture content (%) = [(ab) / a] x 100 In the formula 1, a is the weight of the wet gel blanket before drying; b is the weight of the wet gel blanket after drying in a convection oven at 150° C. for 24 hours.

2. The thermal control element of claim 1 , wherein the wet gel blanket has a moisture content of 60% or more and 90% or less.

3. 2. The thermal control element of claim 1, wherein the wet gel has an average pore size of 1 nm or more and 50 nm or less when the wet gel blanket is dried in a convection oven at 150°C for 24 hours.

4. 2. The thermal control element of claim 1, wherein the wet gel blanket has a thermal conductivity of 30 mW / mK or more and 70 mW / mK or less when dried in a convection oven at 150°C for 24 hours.

5. The thermal control element of claim 1 , wherein the wet gel blanket is a silica wet gel blanket.

6. The wet gel blanket includes a wet gel and a blanket substrate; 2. The thermal control element according to claim 1, wherein the blanket substrate is at least one selected from the group consisting of a film, a sheet, a net, a fiber, a porous body, a foam, and a nonwoven fabric body.

7. The thermal control element of claim 1 , wherein the case is a pouch.

8. The thermal control element of claim 7 , wherein the pouch is made of polyethylene (PE), polyester (PET), polypropylene (PP), aluminum, or a composite material thereof.

9. A battery comprising the thermal control element of any one of claims 1 to 8.

10. 1) providing a silica sol; 2) preparing a case containing a blanket substrate therein; 3) injecting the silica sol into a case, impregnating the blanket substrate with the silica sol, and sealing the case; 4) gelling the silica sol impregnated into the blanket substrate to form a silica wet gel blanket.

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