Phase change microcapsule, aerogel sealing gasket, preparation method of aerogel sealing gasket, battery pack and electric device

Abstract

The invention provides a phase change microcapsule, an aerogel sealing gasket, a preparation method of the aerogel sealing gasket, a battery pack and an electric device. The phase change microcapsule comprises a capsule wall and a capsule core, the capsule wall comprises a thermoplastic resin matrix, and the thermoplastic resin matrix comprises at least one of homopolymers or copolymers of the following monomers: an acrylonitrile monomer, an acrylic acid monomer, an acrylic ester monomer, an acrylamide monomer and a styrene monomer; the capsule core comprises liquid alkane with a boiling point of less than or equal to 85 DEG C. The problem that a traditional aerogel heat insulation pad is poor in heat insulation effect is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal insulation materials, in particular to a phase change microcapsule, an aerogel sealing gasket, a preparation method thereof, a battery pack and an electric device. BACKGROUND

[0002] Thermal runaway is the main cause of power battery safety accidents, and collision, needle puncture, overcharge and overdischarge can cause thermal runaway of lithium batteries. The aerogel thermal insulation plate is mainly used between the battery cells and has certain thermal insulation and buffering functions, and plays a role in preventing thermal runaway. While the aerogel has thermal insulation, as a buffer material between the battery cells, it also needs a certain degree of expansion to adapt to the stress changes during the charging and discharging process of the battery cells. The traditional aerogel has limited thermal insulation effect. SUMMARY

[0003] The present application is made in view of the above-mentioned problems, and aims to provide a phase change microcapsule, an aerogel sealing gasket, a preparation method thereof, a battery pack and an electric device, which solves the problem of poor thermal insulation effect of the traditional aerogel thermal insulation pad.

[0004] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions.

[0005] The first aspect of the present application provides a phase change microcapsule, comprising a capsule wall and a capsule core; the capsule wall comprises a thermoplastic resin matrix, and the thermoplastic resin matrix comprises at least one of the following monomers: acrylonitrile monomers, acrylic monomers, acrylate monomers, acrylamide monomers and styrene monomers; the capsule core comprises a liquid alkane with a boiling point of ≤85℃.

[0006] Thus, the present application uses low-boiling-point alkanes as the capsule core and specific types of polymers as the thermoplastic resin matrix, and utilizes the synergistic effect between the two to improve the heat absorption effect and expansion force of the phase change microcapsule, so that the phase change microcapsule can improve the thermal insulation effect and the expansion durability of the material when added to the aerogel thermal insulation pad.

[0007] In any embodiment, the alkane comprises at least one of the following compounds: butane, pentane, hexane, cyclohexane, petroleum ether;

[0008] And / or, the acrylonitrile monomer comprises any one or a combination of at least two of acrylonitrile, methacrylonitrile, alpha-chloroacrylonitrile or alpha-ethoxyacrylonitrile;

[0009] And / or, the acrylic monomer comprises any one or a combination of at least two of acrylic acid, methacrylic acid, ethyl acrylic acid;

[0010] And / or, the propylene ester monomers include any one or a combination of at least two of the following: methyl acrylate, methyl methacrylate, methyl 2-methacrylate, ethyl 2-methacrylate, isooctyl acrylate, ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, butylene diacrylate, and butylene dimethacrylate.

[0011] And / or, the acrylamide monomers include any one or a combination of at least two of acrylamide, methacrylamide, isopropylacrylamide, hydroxymethylacrylamide, N-trimethylolmethylacrylamide, dimethylacrylamide, diethylacrylamide, and diacetoneacrylamide;

[0012] And / or, the styrene monomers include any one or a combination of at least two of styrene, α-methylstyrene, tert-butylstyrene, and divinylbenzene.

[0013] By using the above-mentioned combinations of alkanes and monomers, phase change microcapsules exhibit higher endothermic properties and expansion capacity.

[0014] In any embodiment, the thermoplastic resin matrix comprises a polymer formed by polymerization of acrylamide monomers, and / or a polymer formed by copolymerization of acrylamide monomers with at least one of acrylonitrile monomers, acrylic monomers, propylene ester monomers, and styrene monomers. When the monomers contain acrylamides, the degree of crosslinking during polymerization is higher, resulting in a resin with stronger toughness and better expansion durability.

[0015] In any embodiment, the thermoplastic resin matrix comprises a polymer copolymerized from acrylonitrile, methyl methacrylate, acrylamide, and ethylene glycol di(meth)acrylate. Resins formed by the polymerization of these monomers exhibit good mechanical properties, such as strength.

[0016] In any embodiment, the alkane in the phase change microcapsule accounts for 20%-30% by mass.

[0017] The second aspect of this application provides a method for preparing phase change microcapsules of the first aspect, comprising: mixing composition A and composition B separately, then mixing the two together, reacting under heating conditions, and drying the product to obtain phase change microcapsules;

[0018] The composition A comprises a monomer combination, a liquid alkane with a boiling point ≤85°C, an initiator, and an optional solvent; the monomer combination comprises at least one of the following monomers: acrylonitrile monomers, acrylic monomers, propylene ester monomers, acrylamide monomers, and styrene monomers;

[0019] The composition B comprises water, a dispersant, and a first emulsifier.

[0020] Therefore, the main component of composition A is oil phase, and the main component of composition B is aqueous phase. After the raw materials are classified and mixed according to the properties of oil and water phases, they are then mixed together for polymerization, which can promote the uniformity of dispersion of the components and help to uniformly and more tightly coat the alkane core in the resin capsule wall, thereby improving the stability of the resulting capsule.

[0021] In any embodiment, the dispersant comprises one or more combinations of colloidal silica, calcium carbonate, calcium phosphate, calcium sulfate, calcium oxalate, and barium carbonate.

[0022] And / or, the first emulsifier comprises any one or a combination of at least two of the following: polyvinyl alcohol, sodium lauryl sulfate, polyvinylpyrrolidone, sodium stearate, sodium lauryl sulfonate, silica sol, polyvinylpyrrolidone, styrene-maleic anhydride copolymer, carboxymethyl cellulose, polyaziridinium, gelatin protein, and lecithin.

[0023] The above types of dispersants and emulsifiers have better compatibility with alkanes and selected monomers, which is more conducive to the uniform and complete polymerization reaction.

[0024] In any embodiment, the mass ratio of the monomer combination, alkane and initiator in composition A is 50-80:20-30:1-3;

[0025] And / or, the mass ratio of dispersant to first emulsifier in composition B is 2-10:0.5-2;

[0026] And / or, the mass ratio of composition A to composition B is 1-1.5:2-10.

[0027] Controlling the proportions of each component and the ratios between components within the above ranges is beneficial for leveraging the synergistic effect of the capsule wall and core, thereby improving the heat absorption and expansion durability of the capsule.

[0028] In any embodiment, composition B further includes at least one of a chloride salt and a polymerization inhibitor;

[0029] And / or, the pH value of composition B is 1 to 3.

[0030] Adding chloride salts can enhance the ionic strength of the solution, promoting rapid and stable polymerization and improving dispersibility. Adding polymerization inhibitors can appropriately control the extent of the polymerization reaction, resulting in polymers with better elasticity. Simultaneously, maintaining a strongly acidic environment with the pH value controlled between 1 and 3 can prevent metal ion precipitation and improve monomer solubility.

[0031] In any embodiment, the polymerization inhibitor includes at least one of sodium nitrite, potassium nitrite, potassium dichromate, and sodium dichromate.

[0032] In any embodiment, the mass ratio of dispersant, first emulsifier, chloride salt, and polymerization inhibitor in composition B is 2-10:0.5-2:1-9:0.5-1. Controlling the dispersant, first emulsifier, chloride salt, and polymerization inhibitor within the above range can promote the fusion of the oil and aqueous phases and accelerate the reaction.

[0033] In any embodiment, the monomer combination comprises acrylonitrile, methyl methacrylate, acrylamide, and ethylene glycol di(meth)acrylate in a mass ratio of 40-50:10-20:3-8:2-4.

[0034] The third aspect of this application provides an aerogel thermal insulation pad, including an aerogel, and phase change microcapsules prepared by the method of the first aspect or the preparation method of the second aspect.

[0035] Therefore, this application incorporates phase change microcapsules into aerogel to create a heat insulation pad, which can significantly improve heat insulation and expansion durability, thus better addressing the issues of cell heating and expansion.

[0036] In any embodiment, it includes: 40-60 parts by weight of aerogel and 15-25 parts by weight of phase change microcapsules.

[0037] If the mass ratio of aerogel to phase change microcapsules is controlled within the above range, the thermal insulation effect and mechanical stability can be better balanced.

[0038] In any embodiment, the aerogel includes at least one of silica aerogel and zirconia aerogel. These aerogels themselves have low thermal conductivity, resulting in better thermal insulation performance when used as the main material of thermal insulation pads. The porosity of the aerogel material can reach over 90%, and the pore size in the aerogel can be in the mesoporous range of 2-50 nm.

[0039] In any embodiment, it further includes at least one of a second emulsifier, a light-blocking agent, a light-blocking agent, and high-silica glass fiber.

[0040] The second emulsifier helps to achieve uniform dispersion between the aerogel and the phase change microcapsules. The light-blocking agent can further enhance the thermal insulation effect while protecting the aerogel.

[0041] In any embodiment, a complexing agent and an amphoteric hydroxide are also included. Adding these two components to the raw materials can form a complex, which can promote the uniform fusion of the aerogel and the phase change microcapsules.

[0042] In any embodiment, the second emulsifier includes one or more of the following: hydroxymethyl cellulose, polyvinylpyrrolidone, sodium alginate, guar gum, starch, polyethylene glycol distearate, styrene-maleic anhydride copolymer, and fatty alcohol polyoxyethylene ether.

[0043] And / or, the light-blocking agent comprises potassium hexatite whiskers.

[0044] In any embodiment, the complexing agent includes at least one selected from sodium citrate, potassium citrate, potassium phosphate, and sodium phosphate; the amphoteric hydroxide includes at least one selected from magnesium hydroxide and aluminum hydroxide. Using a combination of these raw materials can achieve both good thermal insulation performance.

[0045] In any embodiment, it includes: 40-60 parts by weight of aerogel, 15-25 parts by weight of a second emulsifier, 15-25 parts by weight of phase change microcapsules, 3-5 parts by weight of opacifier, and 5-10 parts by weight of high silica glass fiber.

[0046] A fourth aspect of the present invention provides a method for preparing an aerogel heat insulation pad according to the third aspect, comprising:

[0047] After mixing all the ingredients, the mixture is hot-pressed, dried, and then an aerogel heat insulation pad is obtained.

[0048] A fifth aspect of the invention provides a battery pack including the aerogel heat insulation pad of the third aspect.

[0049] A sixth aspect of the present invention provides an electrical device comprising a battery pack according to the fifth aspect. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the structural changes of an aerogel thermal insulation pad containing phase change microcapsules during heat absorption and expansion.

[0051] Figure 2 The thermal conductivity of the insulating pads obtained before and after adding phase change microcapsules varies with temperature. Detailed Implementation

[0052] The following detailed description, with appropriate reference to the accompanying drawings, discloses embodiments of the positive electrode active material, its manufacturing method, positive electrode sheet, secondary battery, battery module, battery pack, and electrical device of this application. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided for the purpose of enabling those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0053] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0054] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0055] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0056] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0057] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0058] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0059] Phase change microcapsules are tiny particles formed by encapsulating solid or liquid phase change materials with film-forming materials. They are materials that can responsively absorb or release energy from the outside world in the form of latent heat through phase transitions, and have good energy storage (cold storage, heat storage) performance. In recent years, they have been widely used in aerospace, building energy conservation, industrial waste heat recovery and other fields. However, there are few reports on their application in the field of battery insulation.

[0060] Current research on phase change microcapsules mainly focuses on their endothermic properties. However, when applying phase change microcapsules to thermal insulation products between battery cells, they require high or stable expansion properties to cope with stress changes during cell charging and discharging. Currently available phase change microcapsules are insufficient to meet these cell expansion requirements.

[0061] Based on this, this application proposes a phase change microcapsule with an improved capsule wall material. The capsule core is a low-boiling-point alkane, and the matrix is ​​a specific type of polymer. The synergistic effect between the two improves the heat absorption effect and expansion force of the phase change microcapsule. Thus, when added to an aerogel insulation pad, it can improve the heat insulation effect and the expansion durability of the material.

[0062] Specifically, the phase change microcapsule of this application includes a capsule wall and a capsule core; the capsule wall includes a thermoplastic resin matrix, and the thermoplastic resin matrix includes at least one of the following monomers homopolymers or copolymers: acrylonitrile monomers, acrylic monomers, propylene ester monomers, acrylamide monomers and styrene monomers; the capsule core includes liquid alkanes with a boiling point ≤85℃.

[0063] Therefore, on the one hand, the low boiling point of alkanes allows them to easily absorb heat and vaporize in a thermal environment, achieving rapid heat absorption and volume expansion. On the other hand, a polymer formed from a specific type of monomer is selected as the thermoplastic resin matrix. This resin has the advantages of high toughness and good elasticity, allowing it to undergo elastic deformation under the impetus of the vaporization and expansion of the internal core, thus expanding in volume. Even after the internal core liquefies and shrinks, it retains high mechanical stability after repeated expansion and contraction, making it less prone to breakage. In other words, the thermoplastic resin of this application, as the wall material, absorbs the volume change of the phase change material during the phase change process, preventing core leakage to a certain extent and reducing the reaction between the phase change material and the external environment, thereby improving the chemical stability of the phase change microcapsules. Therefore, the phase change microcapsules provided in this application have the characteristics of good heat absorption and high expansion durability, which can meet the working environment requirements of the battery cell.

[0064] Taking a thermal insulation pad used between adjacent battery cells as an example, the mechanism by which phase change microcapsules are added to an aerogel thermal insulation pad to exert its thermal insulation effect is mainly as follows. (See also...) Figure 1 When the thermal insulation pad comes into contact with the heat of the battery cell, the core of the phase change microcapsule changes from a liquid to a gaseous state, expanding in volume. The expanded microspheres randomly fill the pores in the aerogel framework, effectively preventing air convection by restricting the free flow of internal air. Furthermore, heat conduction occurs along the pore walls, which are elongated after filling, further reducing heat conduction. Additionally, the expansion of the microspheres thickens the pore walls, reducing radiative heat transfer. Therefore, the phase change microcapsules doped with the pad reduce at least three heat transfer mechanisms: convection, radiation, and conduction, thus improving the pad's heat insulation capability. Moreover, the battery cell undergoes slight volume changes during charging and discharging; the increased internal expansion force of the phase change microcapsule-doped pad effectively alleviates stress changes around the pad. In conclusion, applying the phase change microcapsules of this application to thermal insulation pads between battery cells improves both insulation performance and expansion durability.

[0065] In the aforementioned phase change microcapsules, the core contains liquid alkanes with a boiling point ≤85℃, and may also include additives to prevent alkane escape. Liquid alkanes refer to hydrocarbons that are liquid under normal conditions, thus allowing for heat absorption or release through vaporization-liquefaction phase change. Specifically, the boiling point of liquid alkanes can be ≤85℃, ≤70℃, ≤60℃, or 60~85℃, etc. Boiling point refers to the temperature at which a liquid boils, that is, the temperature at which the saturated vapor pressure of the liquid equals the external pressure. The boiling point of a liquid is usually determined by distillation or fractional distillation. In some embodiments, the liquid alkanes include at least one of the following compounds: butane, pentane, hexane, cyclohexane, and petroleum ether. For example, any one of the above compounds can be used as the core, or a combination of different compounds can be used as the core, thus adapting to heat absorption in different temperature environments. It can be a combination of two alkanes with significantly different boiling points, and the ratio of the combination can be adjusted. In addition to the thermoplastic resin matrix, the capsule wall may also contain additives that improve beneficial properties such as membrane sealing, elasticity, or weather resistance. The monomers used to synthesize the thermoplastic resin matrix can be any one of acrylonitrile monomers, acrylic monomers, propylene ester monomers, acrylamide monomers, and styrene monomers, or copolymers of two, three, four, or all five of these monomers. Specific examples include, but are not limited to, the following: a copolymer of an acrylonitrile monomer and an acrylic monomer, or a copolymer of an acrylic monomer and an propylene ester monomer, or a copolymer of an acrylamide monomer and a styrene monomer, or a copolymer of a styrene monomer and an acrylonitrile monomer, or an acrylamide monomer... A copolymer of a monomer and an acrylonitrile monomer, or a copolymer of an acrylic acid monomer, an acrylate monomer, an acrylamide monomer and a styrene monomer, or a copolymer of an acrylonitrile monomer, an acrylamide monomer and a styrene monomer, or a copolymer of an acrylonitrile monomer, an acrylate monomer and an acrylamide monomer, or a copolymer of an acrylonitrile monomer, two acrylate monomers and an acrylamide monomer, or two acrylonitrile monomers, or two acrylic acid monomers, or two acrylate monomers, or two acrylamide monomers and a styrene monomer.

[0066] For each type of monomer, such as acrylonitrile monomers, acrylic acid monomers, propylene ester monomers, acrylamide monomers, and styrene monomers, they refer to acrylonitrile, acrylic acid, propylene ester, acrylamide, and styrene, or derivatives of the above compounds, respectively. In practical applications, the endothermic properties and expansion force of phase change microcapsules can be improved by selecting different types of alkanes and monomer combinations.

[0067] For example, in some embodiments, the acrylonitrile monomer may include any one or a combination of at least two of acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, or α-ethoxyacrylonitrile.

[0068] In some embodiments, the acrylic monomer may include any one or a combination of at least two of acrylic acid, methacrylic acid, and ethylacrylic acid.

[0069] In some embodiments, propylene monomers may include any one or a combination of at least two of the following: methyl acrylate, methyl methacrylate, methyl 2-methacrylate, ethyl 2-methacrylate, isooctyl acrylate, ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, butylene diacrylate, and dibutylene dimethacrylate.

[0070] In some embodiments, the acrylamide monomer may include any one or a combination of at least two of acrylamide, methacrylamide, isopropylacrylamide, hydroxymethylacrylamide, N-trimethylolmethylmethacrylamide, dimethylacrylamide, diethylacrylamide, and diacetoneacrylamide.

[0071] In some embodiments, styrene monomers may include any one or a combination of at least two of styrene, α-methylstyrene, tert-butylstyrene, and divinylbenzene.

[0072] When the monomer contains acrylamides, the polymerization crosslinking degree is higher, resulting in a resin with stronger toughness and better expansion durability. For example, in some embodiments, the thermoplastic resin matrix may include a polymer formed by polymerization of acrylamide monomers, and / or a polymer formed by copolymerization of acrylamide monomers with at least one of acrylonitrile monomers, acrylic monomers, propylene ester monomers, and styrene monomers.

[0073] The compounds of the various monomers listed above can be combined arbitrarily. For example, in some embodiments, the thermoplastic resin matrix includes a polymer copolymerized from acrylonitrile, methyl methacrylate, acrylamide, and ethylene glycol di(meth)acrylate. Resins polymerized from these monomers have better mechanical properties, such as strength.

[0074] The mass ratio of the capsule core to the capsule wall in the phase change microcapsules of this application can be adjusted. For example, in some embodiments, the mass ratio of alkanes in the phase change microcapsules is 30%, which can increase the latent heat of the phase change microcapsules and improve the encapsulation efficiency.

[0075] The phase change microcapsules of this application can be obtained using a process that simultaneously performs polymerization and coating, which can reduce core loss and improve coating uniformity. For example, in some embodiments, the process of phase change microcapsules includes: separately mixing an oil phase and an aqueous phase, and then mixing them together for reaction. Specifically, it may include a material formed by polymerizing composition A and composition B. Composition A includes a monomer combination, a liquid alkane with a boiling point ≤85°C, an initiator, and optionally a solvent; the monomer combination includes at least one of the following monomers: acrylonitrile monomers, acrylic monomers, propylene ester monomers, acrylamide monomers, and styrene monomers; composition B includes water, a dispersant, and a first emulsifier.

[0076] Therefore, the main components of composition A are oil phase components, and the main components of composition B are aqueous phase components. After the raw materials are classified and mixed according to the properties of the oil and aqueous phases, they are then mixed together for polymerization. This can promote the uniformity of dispersion of the components, which is beneficial to uniformly and more tightly encapsulate the alkane core in the resin capsule wall and improve the stability of the resulting capsule.

[0077] In the preparation method, the addition of an additional organic solvent to composition A can be selected depending on the type of monomer. For example, if some monomers themselves act as solvents, no additional organic solvent needs to be added. The amount of water added to composition B can be adjusted appropriately according to the type and mass of the reactants. The dispersant in composition B improves the uniformity of dispersion, which helps the polymerization reaction proceed rapidly. The primary emulsifier acts as an emulsifier, which can increase the contact area between the oil phase and the aqueous phase, thereby improving the mass transfer efficiency.

[0078] In some embodiments, the dispersant includes one or more combinations of colloidal silica, calcium carbonate, calcium phosphate, calcium sulfate, calcium oxalate, and barium carbonate.

[0079] In some embodiments, the first emulsifier includes any one or a combination of at least two of polyvinyl alcohol, sodium lauryl sulfate, polyvinylpyrrolidone, sodium stearate, sodium lauryl sulfonate, silica sol, polyvinylpyrrolidone, styrene-maleic anhydride copolymer, carboxymethyl cellulose, polyaziridinium, gelatin protein, and lecithin.

[0080] The above-mentioned types of dispersants and primary emulsifiers have better compatibility with alkanes and selected monomers, which is more conducive to the uniform and complete polymerization reaction.

[0081] In the polymerization reactions of the two compositions described above, the amount of alkane is usually determined based on the predetermined coating amount, requiring consideration of both heat absorption and capsule expansion performance; the amount of initiator needs to consider the molecular weight of the resin and its corresponding mechanical properties. For example, in some embodiments, the mass ratio of monomer combination, liquid alkane, and initiator in composition A is 50-80:20-30:1-3, including but not limited to those shown in Table 1 below. In this case, controlling the component ratios of each composition or the ratios between compositions within the above ranges is beneficial for leveraging the synergistic effect of the capsule wall and core, thereby improving the capsule's heat absorption and expansion durability.

[0082] Table 1

[0083]

[0084] Similarly, in some embodiments, the mass ratio of dispersant to first emulsifier in composition B is 2-10:0.5-2, including but not limited to 2:0.5, 2:1, 2:1.5, 2:2, 3:0.5, 3:1, 3:1.5, 3:2, 5:0.5, 5:1, 5:1.5, 5:2, 7:0.5, 7:1, 7:1.5, 7:2, 9:0.5, 9:1, 9:1.5, 9:2, 10:0.5, 10:1, 10:1.5, 10:2, etc. In some embodiments, the mass ratio of dispersant to first emulsifier in composition B is 6-10:0.5-1.5.

[0085] In some embodiments, the mass ratio of composition A to composition B is 1-1.5:2-10.

[0086] In addition, additives that control the extent of the reaction can be added to composition B. For example, in some embodiments, composition B further includes at least one of a chloride salt and a polymerization inhibitor; in this case, the pH value of composition B can be controlled within the range of 1 to 3. Adding a chloride salt can enhance the ionic strength of the solution, promoting a rapid and stable polymerization reaction, while also improving dispersibility. Adding a polymerization inhibitor can appropriately control the extent of the polymerization reaction, resulting in a polymer with better elasticity. Simultaneously, maintaining a strongly acidic environment at a pH value of 1 to 3 can prevent metal ion precipitation and improve monomer solubility. In some embodiments, inorganic acids such as dilute hydrochloric acid or dilute sulfuric acid can be added to adjust the pH value.

[0087] The type of polymerization inhibitor can be selected based on the monomer type and its residual effect on capsule performance. In some embodiments, the polymerization inhibitor may include at least one of sodium nitrite, potassium nitrite, potassium dichromate, and sodium dichromate.

[0088] In some embodiments, the mass ratio of dispersant, first emulsifier, chloride salt, and polymerization inhibitor in composition B is 2-10:0.5-2:1-9:0.5-1. Controlling the dispersant, first emulsifier, chloride salt, and polymerization inhibitor within these ranges can promote the fusion of the oil and aqueous phases and accelerate the reaction.

[0089] In some embodiments, the monomer combination includes acrylonitrile, methyl methacrylate, acrylamide, and ethylene glycol di(meth)acrylate in a mass ratio of 40-50:10-20:3-8:2-4.

[0090] The specific preparation process of phase change microcapsules may include: mixing composition A and composition B separately, then combining them and reacting them under heating conditions. The product is then dried to obtain phase change microcapsules. Mixing can be aided by stirring, sonication, or other methods. The heating temperature and duration can be determined based on the type of polymerization reaction and the desired resin molecular weight / degree of polymerization. A degassing step can be added after the reaction and before drying, for example, degassing under a negative pressure of 0.5 MPa followed by centrifugation at 4000 rpm for approximately 10 minutes. Before drying, the microcapsules can be washed multiple times with ethanol or an ethanol-water solution.

[0091] When the monomer composition includes acrylonitrile, methyl methacrylate, acrylamide, and ethylene glycol di(meth)acrylate, the four monomers can be first mixed at 500 rpm for about 45 minutes, then liquid alkane and initiator are added and mixed thoroughly to form an oil phase. Alternatively, mixing can be achieved by stirring at 0.5 MPa pressure and 800 rpm for 60 minutes. The oil phase is then mixed with the aqueous phase for reaction. Heating and stirring can be used to promote mixing. Stirring can also be performed during the subsequent reaction. The polymerization reaction is typically carried out in an inert atmosphere.

[0092] In addition, capsules with specific particle size ranges can be obtained by means of shearing during the preparation process.

[0093] In addition to aerogel insulation pads, the phase change microcapsules described above in this application can also be applied to coatings, textile composites, and other fields.

[0094] When specifically used in aerogel insulation pads, the insulation pad may include aerogel and the phase change microcapsules described above.

[0095] Therefore, this application incorporates phase change microcapsules into aerogel to create a heat insulation pad, which can significantly improve heat insulation and expansion durability, thus better addressing the issues of cell heating and expansion.

[0096] The doping amount of phase change microcapsules can be determined according to the overall performance requirements of the microcapsules. For example, in some embodiments, it includes: 40-60 parts by mass of aerogel and 15-25 parts by mass of phase change microcapsules. Controlling the mass ratio of aerogel to phase change microcapsules within the above range can better balance thermal insulation effect and mechanical stability.

[0097] Aerogels with good thermal insulation properties are preferred. For example, in some embodiments, the aerogel includes at least one of silica aerogel and zirconia aerogel. These aerogels themselves have low thermal conductivity, resulting in better thermal insulation when used as the main material of the insulation pad.

[0098] Aerogel insulation pads may also contain at least one of a second emulsifier, a light-blocking agent, a light-blocking agent, and high-silica glass fiber.

[0099] The second emulsifier helps to achieve uniform dispersion between the aerogel and the phase change microcapsules. The light-blocking agent further enhances the thermal insulation effect while protecting the aerogel. High-silica glass fiber, as a scaffold material, improves the mechanical properties of the aerogel.

[0100] In addition, a complexing agent and an amphoteric hydroxide can be added simultaneously. Adding these two components to the raw material forms a complex, which promotes the uniform fusion of the aerogel and phase change microcapsules. The complexing agent may include at least one of sodium citrate, potassium citrate, potassium phosphate, and sodium phosphate; the amphoteric hydroxide may include at least one of magnesium hydroxide and aluminum hydroxide. Using this combination of raw materials can achieve both good thermal insulation performance.

[0101] The second emulsifier can be of the same type as the first emulsifier, or it can be selected differently. For example, in some embodiments, the second emulsifier includes one or more of the following: hydroxymethyl cellulose, polyvinylpyrrolidone, sodium alginate, guar gum, starch, polyethylene glycol distearate, styrene-maleic anhydride copolymer, and fatty alcohol polyoxyethylene ether.

[0102] In some embodiments, the light-blocking agent includes potassium hexatite whiskers.

[0103] In some embodiments, the composition includes: 40-60 parts by weight of aerogel, 15-25 parts by weight of a secondary emulsifier, 15-25 parts by weight of phase change microcapsules, 3-5 parts by weight of a light-blocking agent, and 5-10 parts by weight of high-silica glass fiber. Mixing the components in the above-mentioned mass ratio can achieve a better synergistic effect.

[0104] The aerogel thermal insulation pads described above can be prepared using the following methods:

[0105] After mixing all the ingredients, the mixture is hot-pressed, dried, and then an aerogel heat insulation pad is obtained.

[0106] The mixing process can involve adding the components in stages; degassing can be performed before hot pressing; and drying can be carried out in a vacuum drying oven. Hot pressing can also be replaced by other methods, such as 3D printing.

[0107] Aerogel insulation pads can be any shape and size, such as a flat plate with uniform thickness, or a plate with convex ends and concave middle, and the thickness can be arbitrary.

[0108] The above aerogel insulation pads can be used for insulation between battery cells, or in other products that require insulation.

[0109] Taking a battery cell as an example, an aerogel heat insulation pad can be placed in a battery pack consisting of a single battery cell, or it can be placed in a battery pack consisting of multiple battery cells, between adjacent battery cells.

[0110] Furthermore, the battery pack can be used in an electrical device, which may include the battery pack provided in this application. The battery pack can be used as a power source for the electrical device, or as an energy storage unit for the electrical device. The electrical device may include, but is not limited to, mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.

[0111] Example

[0112] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0113] The meanings of the English abbreviations for reagents in the preparation examples and embodiments below are as follows.

[0114] AN: Acrylonitrile; MMA: Methyl methacrylate; AM: Acrylamide; EGDMA: Ethylene glycol di(meth)acrylate; PVA: Polyvinyl alcohol; HMC: Hydroxymethyl cellulose; PEG150: Polyethylene glycol distearate; AIBN: Azobisisobutyronitrile; KOTi: Potassium hexatite whiskers; SOD CITR: Sodium citrate; LPO: Lauroyl peroxide; UREA: Urea; SDS: Sodium dodecyl sulfate; DVB: Divinylbenzene; MEM: Melamine.

[0115] In the preparation examples and comparative examples, "parts" represents parts by weight, and the monomer ratio is by weight.

[0116] Preparation of phase change microcapsules

[0117] Preparation Examples 1-11

[0118] A phase change microcapsule

[0119] Preparation Examples 1-11 used the raw materials and amounts shown in Table 1, and the same preparation process was used to prepare phase change microcapsules. The specific process is described in steps one to three. Step one: The monomers were combined in a polymerization reactor and mixed at 500 rpm for 45 min. Then, the initiator azobisisobutyronitrile and liquid alkane were added. After stirring at 0.5 MPa pressure and 800 rpm for 60 min, a complete oil phase was obtained.

[0120] Step 2: Add dispersant, emulsifier, 5 parts by mass of sodium chloride and 0.5 parts by mass of polymerization inhibitor - potassium dichromate to 300ml of deionized water. Stir at 500rpm for 30min, then add dilute hydrochloric acid to adjust the pH to 3 to obtain the aqueous phase.

[0121] Step 3: Pour the oil phase into the aqueous phase and stir the mixture at 1000 rpm for 15 minutes at 80°C to form an oil / water emulsion. Then pour the emulsion into a three-necked flask, purge with nitrogen, and react at 90°C and 500 rpm for 12 hours. After the reaction, degas the mixture under a negative pressure of 0.5 MPa and centrifuge at 4000 rpm for 10 minutes to obtain microcapsules. The obtained sample is washed three times with 30 wt% ethanol solution, filtered, and then dried in a vacuum oven at 35°C for 24 hours to obtain phase change microcapsules.

[0122] Comparative Example 1

[0123] A phase change microcapsule

[0124] Step 1: In the polymerization reactor, formaldehyde and urea are mixed in weakly alkaline ammonia water at 500 rpm for 45 min. During the pH adjustment process, a trace amount of melamine is added to generate a relatively stable hydroxymethylurea monomer. Then, lauroyl peroxide and liquid alkanes are added to the mixture. After stirring at 0.5 MPa pressure and 800 rpm for 60 min, a complete oil phase can be obtained.

[0125] Step 2: Add dispersant, emulsifier, 5 parts by weight of sodium chloride and 0.5 parts by weight of potassium dichromate to 300ml of deionized water. Stir at 500rpm for 30min, then add dilute hydrochloric acid to adjust the pH to 3 to obtain the aqueous phase.

[0126] Step 3: Pour the oil phase into the aqueous phase and stir the mixture at 1000 rpm for 15 minutes at 80°C to form an oil / water emulsion. Then pour the emulsion into a three-necked flask, purge with nitrogen, and react at 90°C and 500 rpm for 12 hours. After the reaction, degas the mixture under a negative pressure of 0.5 MPa and centrifuge at 4000 rpm for 10 minutes to obtain microcapsules. The obtained sample is washed three times with 30 wt% ethanol solution, filtered, and then dried in a vacuum oven at 35°C for 24 hours to obtain phase change microcapsules.

[0127] Table 2

[0128]

[0129]

[0130] Preparation Examples 12-14

[0131] A phase change microcapsule

[0132] The main difference between Preparation Examples 12-14 and Preparation Example 1 is that the amounts of sodium chloride and polymerization inhibitor added in step three are different, see Table 2; the rest of the process is the same as Preparation Example 1, as follows.

[0133] Step 1: Mix the monomer combination (AN:MMA:AM:EGDMA = 45:15:5:3, a total of 68 parts) in a polymerization reactor at 500 rpm for 45 min. Then add 2 parts of initiator - azobisisobutyronitrile and 25 parts of liquid alkane - isopentane. Stir at 0.5 MPa pressure and 800 rpm for 60 min to obtain a complete oil phase.

[0134] Step 2: Add 5 parts of dispersant-SiO2 and 2 parts of emulsifier-PVA to 300ml of deionized water, stir at 500rpm for 30min, then add dilute hydrochloric acid to adjust the pH to 3 to obtain the aqueous phase.

[0135] Step 3: Pour the oil phase into the aqueous phase and stir the mixture at 1000 rpm for 15 minutes at 80°C to form an oil / water emulsion. Then pour the emulsion into a three-necked flask, purge with nitrogen, and react at 90°C and 500 rpm for 12 hours. After the reaction, degas the mixture under a negative pressure of 0.5 MPa and centrifuge at 4000 rpm for 10 minutes to obtain microcapsules. The obtained sample is washed three times with 30 wt% ethanol solution, filtered, and then dried in a vacuum oven at 35°C for 24 hours to obtain phase change microcapsules.

[0136] Table 3

[0137] Sodium chloride Potassium dichromate Preparation example 1 5 parts 0.5 parts Preparation example 12 0 parts 0 parts Preparation example 13 1 part 0.1 part Preparation example 14 10 parts 1 part

[0138] Preparation of aerogel sealing gaskets

[0139] Examples 1-14

[0140] An aerogel sealing pad

[0141] Step 1: Mix 27.5 parts by weight of silica aerogel (porosity of over 90%, pore size in the mesoporous range of 2-50nm), 10 parts by weight of polyethylene glycol distearate, 1 part by weight of hydroxymethyl cellulose and 16.5 parts by weight of water in a mixing tank and mechanically stir at 750 rpm for 20 minutes until uniformly mixed to obtain an aerogel slurry.

[0142] Step 2: Add 6 parts by weight of sodium citrate to the aerogel slurry, then add 17 parts by weight of phase change microcapsules (see Table 4) and stir at 1000 rpm for 10 min. Then reduce the stirring speed to 300 rpm and add 10 parts by weight of aluminum hydroxide, 5 parts by weight of potassium hexatitanate whiskers, and 7 parts by weight of high-silica glass fiber in sequence. A preliminary mixed slurry is obtained.

[0143] Step 3: After mixing the slurry for 20 minutes, it is placed in a negative pressure mixing tank and vacuum stirred and degassed under a speed of 600 rpm and a negative pressure of 0.8 MPa to obtain a degassed slurry.

[0144] Step 4: Add the defoamed slurry to a mold preheated to 100℃, and press it under a hydraulic pressure of 200 kg / cm². 3 The mold was placed in a hydraulic press at 150℃ and heated to form the material. The resulting sheet was then dried in a vacuum drying oven at 85℃ for 6 hours to obtain a phase change aerogel insulation pad with a thickness of 10mm.

[0145] Comparative Example 1

[0146] Except for the phase change microcapsules, the rest is the same as in Example 1.

[0147] Comparative Example 2

[0148] No phase change microcapsules were added; otherwise, it was the same as in Example 1.

[0149] Performance testing

[0150] 1. Thermal conductivity

[0151] The thermal insulation performance of the insulation pads was assessed using their thermal conductivity. Referring to GB / T 10295 2008, the thermal conductivity (100℃) of the insulation pads in each embodiment and comparative example was tested. During measurement, the insulation pad sample was inserted between two flat plates, with a specific temperature gradient established. A calibrated heat flow sensor was used to measure the heat flow through the sample, with the sensor in contact with the sample between the flat plates. The thermal conductivity of the sample was calculated by measuring the sample thickness, the temperature gradient between the upper and lower plates, and the heat flow through the sample.

[0152] The thermal conductivity curves of the insulation pads obtained in Example 1 (after the addition of phase change microcapsules) and Comparative Example 2 (before the addition of phase change microcapsules) as a function of temperature are shown below. Figure 2 .

[0153] 2. Expansion performance

[0154] The limit of expansion: The sample is heated to 100°C, and the thickness of the sample after expansion is measured at this temperature. The rate of change of the maximum thickness after expansion is calculated compared with the initial thickness (10 mm).

[0155] Expansion durability: The aerogel insulation pad was placed in a 100°C heating chamber, then removed and allowed to cool to room temperature, constituting one cycle. This cycle was repeated three times. The insulation pad thickness during the change process was recorded as the maximum thickness retention rate compared to the expandable limit.

[0156] Table 4

[0157]

[0158]

[0159] The results showed that the implemented case was significantly superior to the comparative case. This was attributed to the enhanced expansion force of the acrylonitrile monomer composite wall material resin on the aerogel insulation pad, and the performance of the composite monomers was better than that of the polymerization of a single monomer. The addition of amides improved the overall performance of the product, enhancing its heat resistance and wear resistance, making it suitable for filler reinforcement modification. The increase of alkanes improved the phase change effect to some extent, but was detrimental to expansion performance. The addition of metal salts improved dispersibility and uniformity to some extent, but excessive addition may have an adverse effect on polymerization inhibition.

[0160] Examples 15-16

[0161] The difference from Example 1 is that the doping amount of the phase change microcapsules is different (the total number of components remains the same), otherwise it is the same as Example 1.

[0162] Table 5

[0163]

[0164] The results showed that when the proportion of phase change microcapsules was too high, the improvement in thermal conductivity of the aerogel insulation pad was limited, and the stability decreased. When the proportion of aerogel was too high, the thermal conductivity and expansion were very poor. The addition of phase change microcapsules could improve the expansion of the aerogel insulation pad.

[0165] Example 17

[0166] The difference from Example 1 is that the type of aerogel is different (the total number of parts remains the same), otherwise it is the same as Example 1.

[0167] Table 6

[0168] Aerogel Thermal conductivity W / (m*K) Limit value of expandability Swelling durability Example 1 Silicon dioxide 0.027 106.7％ 98.6％ Example 17 Aluminium oxide 0.030 105.4％ 98.7％

[0169] The results showed that alumina aerogel had a better thermal conductivity than silica, resulting in a product with lower thermal insulation performance than silica aerogel.

[0170] Example 18

[0171] The difference from Example 1 is that sodium citrate and aluminum hydroxide were not added in step two; otherwise, it is the same as Example 1.

[0172] Table 7

[0173] Thermal conductivity W / (m*K) Limit value of expandability Swelling durability Example 1 0.027 106.7％ 98.6％ Example 18 0.032 105.3％ 98.2％

[0174] The results showed that the addition of sodium citrate and aluminum hydroxide could increase the viscosity of the mixed emulsion through complexation reaction, further preventing the agglomeration of solids in the emulsion, and preventing uneven dispersion of phase change capsules and unsatisfactory heat insulation effect.

[0175] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A phase change microcapsule, characterized in that, It includes a capsule wall and a capsule core; the capsule wall includes a thermoplastic resin matrix, which includes at least one homopolymer or copolymer of the following monomers: acrylonitrile monomers, acrylic monomers, propylene ester monomers, acrylamide monomers, and styrene monomers; the capsule core includes liquid alkanes with a boiling point ≤85℃.

2. The phase change microcapsule according to claim 1, characterized in that, Liquid alkanes with a boiling point ≤85℃ include at least one of the following compounds: butane, pentane, hexane, cyclohexane, and petroleum ether.

3. The phase change microcapsule according to claim 1, characterized in that, The acrylonitrile monomers include any one or a combination of at least two of acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, or α-ethoxyacrylonitrile. And / or, the acrylic monomers include any one or a combination of at least two of acrylic acid, methacrylic acid, and ethylacrylic acid; And / or, the propylene ester monomers include any one or a combination of at least two of the following: methyl acrylate, methyl methacrylate, methyl 2-methacrylate, ethyl 2-methacrylate, isooctyl acrylate, ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, butylene diacrylate, and butylene dimethacrylate. And / or, the acrylamide monomers include any one or a combination of at least two of acrylamide, methacrylamide, isopropylacrylamide, hydroxymethylacrylamide, N-trimethylolmethylacrylamide, dimethylacrylamide, diethylacrylamide, and diacetoneacrylamide; And / or, the styrene monomers include any one or a combination of at least two of styrene, α-methylstyrene, tert-butylstyrene, and divinylbenzene.

4. The phase change microcapsule according to any one of claims 1-3, characterized in that, The thermoplastic resin matrix includes polymers formed by polymerizing acrylamide monomers, and / or polymers formed by copolymerizing acrylamide monomers with at least one of acrylonitrile monomers, acrylic monomers, propylene ester monomers, and styrene monomers.

5. The phase change microcapsule according to claim 4, characterized in that, The thermoplastic resin matrix comprises a polymer copolymerized from acrylonitrile, methyl methacrylate, acrylamide, and ethylene glycol di(meth)acrylate.

6. The phase change microcapsule according to any one of claims 1-3, characterized in that, The alkane in the phase change microcapsules accounts for 20%-30% by mass.

7. The method for preparing phase change microcapsules according to any one of claims 1-6, characterized in that, include: Composition A and composition B were mixed separately, then the two were combined and reacted under heating conditions. The product was dried to obtain phase change microcapsules. The composition A comprises a monomer combination, a liquid alkane with a boiling point ≤85°C, an initiator, and an optional solvent; the monomer combination comprises at least one of the following monomers: acrylonitrile monomers, acrylic monomers, propylene ester monomers, acrylamide monomers, and styrene monomers; The composition B comprises water, a dispersant, and a first emulsifier.

8. The preparation method according to claim 7, characterized in that, The dispersant includes one or more combinations of colloidal silica, calcium carbonate, calcium phosphate, calcium sulfate, calcium oxalate, and barium carbonate. And / or, the first emulsifier comprises one or more combinations of polyvinyl alcohol, sodium lauryl sulfate, polyvinylpyrrolidone, sodium stearate, sodium lauryl sulfonate, silica sol, polyvinylpyrrolidone, styrene-maleic anhydride copolymer, carboxymethyl cellulose, polyaziridinium, gelatin protein, and lecithin. And / or, in composition A, the mass ratio of monomer combination, alkane and initiator is 50-80:20-30:1-3; And / or, the mass ratio of dispersant to first emulsifier in composition B is 2-10:0.5-2; And / or, the mass ratio of composition A to composition B is 1-1.5:2-10.

9. The preparation method according to claim 7, characterized in that, The composition B further includes at least one of a chloride salt and a polymerization inhibitor; And / or, the pH value of composition B is 1 to 3.

10. The preparation method according to claim 9, characterized in that, The polymerization inhibitor includes at least one of sodium nitrite, potassium nitrite, potassium dichromate, and sodium dichromate.

11. The preparation method according to claim 9 or 10, characterized in that, The mass ratio of dispersant, first emulsifier, chloride salt and polymerization inhibitor in composition B is 2-10:0.5-2:1-9:0.5-1.

12. The preparation method according to any one of claims 7-11, characterized in that, The monomer combination includes acrylonitrile, methyl methacrylate, acrylamide, and ethylene glycol di(meth)acrylate, with a mass ratio of 40-50:10-20:3-8:2-4.

13. An aerogel heat insulation pad, characterized in that, Its features are, Including aerogels and phase change microcapsules as described in any one of claims 1-12.

14. The aerogel thermal insulation pad according to claim 13, characterized in that, include: By weight, 40-60 parts of aerogel and 15-25 parts of phase change microcapsules.

15. The aerogel thermal insulation pad according to claim 13 or 14, characterized in that, The aerogel includes at least one of silica aerogel and zirconia aerogel.

16. The aerogel thermal insulation pad according to claim 13 or 14, characterized in that, It also includes at least one of a second emulsifier, a light-blocking agent, and high-silica glass fiber; And / or, also includes complexing agents and amphoteric hydroxides.

17. The aerogel thermal insulation pad according to claim 16, characterized in that, The second emulsifier includes one or more of the following: hydroxymethyl cellulose, polyvinylpyrrolidone, sodium alginate, guar gum, starch, polyethylene glycol distearate, styrene-maleic anhydride copolymer, and fatty alcohol polyoxyethylene ether. And / or, the light-blocking agent comprises potassium hexatite whiskers.

18. The aerogel thermal insulation pad according to claim 16, characterized in that, The complexing agent includes at least one of sodium citrate, potassium citrate, potassium phosphate, and sodium phosphate; the amphoteric hydroxide includes at least one of magnesium hydroxide and aluminum hydroxide.

19. The aerogel thermal insulation pad according to claim 16, characterized in that, include: By weight, 40-60 parts aerogel, 15-25 parts emulsifier, 15-25 parts phase change microcapsules, 3-5 parts opacifier, and 5-10 parts high silica glass fiber.

20. The aerogel thermal insulation pad according to claim 16, characterized in that, Also includes: By mass, 8-10 parts of amphoteric hydroxide and 5-10 parts of complexing agent.

21. A method for preparing the aerogel thermal insulation pad according to any one of claims 13-20, characterized in that, include: After mixing all the ingredients, the mixture is hot-pressed, dried, and then an aerogel heat insulation pad is obtained.

22. A battery pack comprising the aerogel insulation pad according to any one of claims 13-20.

23. An electrical device comprising the battery pack of claim 22.

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