Self-repairable flexible phase change energy storage material constructed based on water-in-oil emulsification system and preparation method of self-repairable flexible phase change energy storage material

Abstract

The invention discloses a self-repairing flexible phase change energy storage material constructed based on a water-in-oil emulsion system and a preparation method of the self-repairing flexible phase change energy storage material, and belongs to the field of energy storage materials.The self-repairing flexible phase change energy storage material is prepared through the water-in-oil emulsion system, amino silicon oil jointly modified by isophorone diisocyanate and 4, 4 '-diaminodiphenyl disulfide is adopted as a continuous phase, and the self-repairing flexible phase change energy storage material is prepared through the water-in-oil emulsion system. The crystallized hydrated salt phase-change material is used as a dispersion phase, and the flexible phase-change material with a bean-pod-shaped structure is finally formed by using high-speed emulsification and silicone oil cross-linking curing technologies. The phase change energy storage material disclosed by the invention has excellent flexibility, thermal stability and leak-proof performance, is suitable for various energy storage application scenes, and has the advantages of simple and easily-controlled reaction process, short production period and low production cost.

Description

Technical Field

[0001] The present invention belongs to the field of energy storage materials and relates to a self-repairing flexible phase-change energy storage material constructed based on an oil-in-water emulsion system and a preparation method thereof. Background Art

[0002] The continuous growth of energy demand and the excessive consumption of fossil fuels have led to a series of environmental problems and exacerbated the global greenhouse effect. This has made the development of new renewable clean energy and the improvement of energy utilization efficiency the key topics in the current research field in order to cope with the energy crisis and environmental challenges. In this context, phase change energy storage materials play a key role in alleviating the imbalance between energy supply and demand because they can effectively store large amounts of renewable and sustainable thermal energy through reversible heat storage mechanisms. In addition, phase change energy storage materials have shown significant advantages in energy storage capacity, energy efficiency improvement, temperature regulation and thermal management. They have been widely used in thermal energy storage and thermal management systems, providing important support for sustainable energy utilization.

[0003] Common phase change energy storage materials include higher aliphatic hydrocarbons (n-hexadecane, n-octadecane, paraffin, etc.), fatty acids and their esters (stearic acid, palmitic acid, etc.), crystalline hydrated salts (Na2SO4·10H2O, Mn(NO3)2·6H2O, Na2HPO4·12H2O, etc.), molten salts (LiF, NaF, CaF2, etc.), metals and alloys (lead-tin alloy, etc.) and polymers (polyethylene glycol, etc.). However, these materials have the following problems in practical applications:

[0004] Liquid leakage problem: Traditional phase change materials are prone to liquid leakage during the solid-liquid phase change process, affecting their service life and safety.

[0005] Strong rigidity and lack of flexibility: Most phase change materials exhibit strong rigidity in the solid state, making it difficult to adapt to devices or scenarios with complex shapes.

[0006] Poor thermal cycling stability: After multiple thermal cycles, some phase change materials will experience phase separation or performance degradation.

[0007] Existing technologies typically address these issues by embedding phase-change materials into inorganic porous materials (such as silica aerogels) or organic polymer matrices. However, these approaches suffer from complex preparation processes, limited flexibility, and high costs. Consequently, there is a lack of a flexible phase-change energy storage material that is simple to prepare and offers excellent performance. Summary of the Invention

[0008] The purpose of the present invention is to provide a self-repairing flexible phase change energy storage material constructed based on an oil-in-water emulsion system and a preparation method thereof, which solves the current problem of the lack of a phase change energy storage material that is simple to prepare, has excellent performance and is flexible.

[0009] The technical solution adopted in the present invention is as follows:

[0010] A self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system, comprising a continuous phase, a dispersed phase, and an additive;

[0011] The continuous phase is modified amino silicone oil, and the modified amino silicone oil includes isophorone diisocyanate, 4,4'-diaminodiphenyl disulfide and amino silicone oil;

[0012] The dispersed phase includes an inorganic phase change material;

[0013] The auxiliary agents include emulsifiers and catalysts.

[0014] In the present invention, isophorone diisocyanate and 4,4'-diaminodiphenyl disulfide modified amino silicone oil are used as the main components of the continuous phase. The R-NH2 functional group in the amino silicone oil and the R-NH2 functional group in 4,4'-diaminodiphenyl disulfide react with the -N=C=O bond in the isophorone diisocyanate to form an -NH-CO-NH- structure under the action of a catalyst such as an organic tin catalyst, thereby constructing a three-dimensional cross-linked network structure, which can adjust the hardness, elasticity and flexibility of the material; at the same time, the modified amino silicone oil has a dynamic disulfide bond and can play a role in Self-healing effect; emulsifiers are used to stabilize the oil-in-water emulsion system to prevent phase separation between the dispersed phase and the continuous phase; catalysts (such as organic tin catalysts) are used to accelerate the cross-linking reaction between amino silicone oil, 4,4'-diaminodiphenyl disulfide and isophorone diisocyanate, and promote the formation of a three-dimensional network structure; during the emulsification process, the phase change material is encapsulated in the continuous phase to form tiny droplets, which are fixed in the continuous phase to form a pod-like structure. This structure not only improves the dispersion uniformity of the phase change material, but also enhances the mechanical properties and thermal stability of the material.

[0015] Furthermore, the inorganic phase change material is a crystalline hydrated salt material.

[0016] Furthermore, the inorganic phase change material is at least one of Na2SO4·10H2O, Mn(NO3)2·6H2O, Na2HPO4·12H2O, CaCl2·6H2O, Na2CO3·10H2O, LiClO3·3H2O, FeCl3·6H2O, and MgSO4·7H2O.

[0017] Furthermore, the amino silicone oil has a 3-aminopropyl functional group and the -NH2 content of the amino silicone oil is 0.23 to 0.9 wt%.

[0018] Furthermore, the mass ratio of the amino silicone oil, isophorone diisocyanate, and 4,4'-diaminodiphenyl disulfide is (14-64): (1.3-3.1):1.

[0019] Furthermore, the emulsifier is at least one of sorbitan monooleate, sorbitan trioleate, polysorbate 80, polysorbate-20, PEG-10 polydimethylsiloxane, and cetyl polyethylene glycol / polypropylene glycol-10 / 1 dimethylsiloxane copolymer; the amount of the emulsifier is 2% to 5% of the mass of the inorganic phase change material.

[0020] Furthermore, the catalyst is an organic tin catalyst, which includes at least one of dibutyltin dilaurate, dibutyltin didodecylsulfide, and dibutyltin diacetate catalysts; the amount of the organic tin catalyst is 0.3% to 0.6% of the mass of the modified amino silicone oil.

[0021] Furthermore, the mass ratio of the inorganic phase change material to the modified amino silicone oil is 1:0.7-5.

[0022] A method for preparing a self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system comprises the following steps:

[0023] S1. Add amino silicone oil, isophorone diisocyanate, 4,4'-diaminodiphenyl disulfide, and emulsifier into a high-speed disperser with a stirring speed of 2000-8000 rpm and a reaction temperature of 20-80°C. Slowly add the molten inorganic phase change material under high-speed dispersion and keep stirring for 0.5-3 hours to form a stable water-in-oil emulsion;

[0024] S2. Add a catalyst to the water-in-oil emulsion, stir evenly, pour the emulsion into a mold, and cure it at 40-100°C for 12-48 hours to obtain a self-repairable flexible phase change energy storage material.

[0025] Furthermore, the self-repairable flexible phase change energy storage material is a pod-shaped flexible phase change material.

[0026] The reaction path of the present invention is as follows:

[0027]

[0028] The present invention is based on the above formula and reuses high-speed emulsification and silicone oil cross-linking and curing technology to finally form a flexible phase change material with a pod-like structure. The phase change material is dispersed in a discontinuous state, which greatly improves the flexibility of the material and is suitable for various complex application scenarios; the phase change material of the present invention is completely wrapped by the silicone matrix, fundamentally solving the performance defect of liquid leakage during the solid-liquid phase change process of the phase change material.

[0029] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0030] 1. The present invention's self-repairable, flexible phase-change energy storage material, constructed based on a water-in-oil emulsion system, features a phase-change material completely encapsulated by an organosilicon matrix, fundamentally resolving the performance drawback of liquid leakage during the solid-liquid phase transition of the phase-change material.

[0031] 2. The phase-change energy storage material of the present invention has a pod-like structure, and the phase-change material is dispersed in a discontinuous state, which greatly improves the flexibility of the material and is suitable for various complex application scenarios;

[0032] 3. The preparation method of the phase change energy storage material of the present invention adopts an oil-in-water emulsification system and silicone oil cross-linking and curing technology, which is simple and easy to implement and can be easily industrialized. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be considered as limiting the scope. A person of ordinary skill in the art can also derive other relevant drawings based on these drawings without inventive effort, among which:

[0034] Figure 1 is a DSC graph of the product obtained in Example 1;

[0035] Figure 2 It is a mechanical property curve diagram of the product obtained in Example 1. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present invention and are not intended to limit the present invention. That is, the embodiments described herein are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and illustrated in the drawings herein may be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely intended to represent selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0038] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0039] The present invention discloses a self-repairing flexible phase change energy storage material based on a water-in-oil emulsion system, comprising a continuous phase, a dispersed phase and an additive;

[0040] The continuous phase is modified amino silicone oil, and the modified amino silicone oil includes isophorone diisocyanate, 4,4'-diaminodiphenyl disulfide and amino silicone oil;

[0041] The dispersed phase includes an inorganic phase change material;

[0042] The auxiliary agents include emulsifiers and catalysts.

[0043] The inorganic phase change material is a crystalline hydrated salt material, and the inorganic phase change material is at least one of Na2SO4·10H2O, Mn(NO3)2·6H2O, Na2HPO4·12H2O, CaCl2·6H2O, Na2CO3·10H2O, LiClO3·3H2O, FeCl3·6H2O, and MgSO4·7H2O.

[0044] The amino silicone oil has a 3-aminopropyl functional group and the -NH2 content of the amino silicone oil is 0.23 to 0.9 wt%.

[0045] The mass ratio of the amino silicone oil, isophorone diisocyanate and 4,4'-diaminodiphenyl disulfide is (14-64): (1.3-3.1):1.

[0046] The emulsifier is at least one of sorbitan monooleate, sorbitan trioleate, polysorbate 80, polysorbate-20, PEG-10 polydimethylsiloxane, and cetyl polyethylene glycol / polypropylene glycol-10 / 1 dimethylsiloxane copolymer; the amount of the emulsifier used is 2% to 5% of the mass of the inorganic phase change material.

[0047] The catalyst is an organic tin catalyst, which includes at least one of dibutyltin dilaurate, dibutyltin didodecylsulfide and dibutyltin diacetate. The amount of the organic tin catalyst is 0.3% to 0.6% of the mass of the modified amino silicone oil.

[0048] The mass ratio of the inorganic phase change material to the modified amino silicone oil is 1:0.7-5.

[0049] A method for preparing a self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system comprises the following steps:

[0050] S1. Add amino silicone oil, isophorone diisocyanate, 4,4'-diaminodiphenyl disulfide, and emulsifier into a high-speed disperser with a stirring speed of 2000-8000 rpm and a reaction temperature of 20-80°C. Slowly add the molten inorganic phase change material under high-speed dispersion and keep stirring for 0.5-3 hours to form a stable water-in-oil emulsion;

[0051] S2. Add a catalyst to the water-in-oil emulsion, stir evenly, pour the emulsion into a mold, and cure it at 40-100°C for 12-48 hours to obtain a self-repairable flexible phase change energy storage material.

[0052] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0053] Example 1

[0054] A preferred embodiment of the present invention provides a method for preparing a self-repairable flexible phase change energy storage material based on an oil-in-water emulsion system, comprising the following steps:

[0055] 89.8g of amino silicone oil (-NH2 content of 0.4wt%), 7.4g of isophorone diisocyanate, 2.8g of 4,4'-diaminodiphenyl disulfide, and 4g of cetyl polyethylene glycol / polypropylene glycol-10 / 1 dimethylsiloxane copolymer were added to a high-speed disperser. After heating to 50°C, 100g of molten calcium chloride hexahydrate (CaCl2·6H2O) was slowly added under high-speed dispersion (speed of 4000rpm) and stirred for 1h to form a stable oil-in-water emulsion; 0.3g of dibutyltin disilicic acid was added to the emulsion, stirred evenly, and then poured into a mold and cured at 60°C for 24h to obtain a self-healing flexible phase change energy storage material.

[0056] The product prepared in this example is a yellow film-like solid, and the DSC spectrum is as follows Figure 1 As shown in FIG1 , the phase transition point of the flexible phase change energy storage film prepared in Example 1 during the heating process is about 29.2°C, and the phase change enthalpy is 95.3 J / g; the mechanical properties test diagram of the flexible phase change energy storage film prepared in Example 1 is shown in FIG1 Figure 2 As shown, the flexible phase-change energy storage film prepared in Example 1 has an elongation at break of 286% and a fracture stress of 2.07 MPa in a tensile test.

[0057] Example 2

[0058] This embodiment provides a method for preparing a self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system, comprising the following steps:

[0059] 70.5 g of amino silicone oil (-NH2 content of 0.23 wt%), 3.4 g of isophorone diisocyanate, 1.1 g of 4,4'-diaminodiphenyl disulfide, and 2 g of PEG-10 polydimethylsiloxane were added to a high-speed disperser. After heating to 80°C, 100 g of molten sodium carbonate decahydrate Na2CO3·10H2O was slowly added under high-speed dispersion (speed of 2000 rpm) and stirred for 0.5 h to form a stable oil-in-water emulsion; 0.3 g of dibutyltin(dodecylsulfide) was added to the emulsion, stirred evenly, and then poured into a mold. After curing at 100°C for 12 h, a self-healing flexible phase change energy storage material was obtained.

[0060] Example 3

[0061] This embodiment provides a method for preparing a self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system, comprising the following steps:

[0062] 426.8 g of amino silicone oil (-NH2 content of 0.6 wt%), 53.4 g of isophorone diisocyanate, 19.8 g of 4,4'-diaminodiphenyl disulfide, and 5 g of polysorbate 20 were added to a high-speed disperser. After the reaction temperature reached 20°C, 100 g of molten lithium chlorite trihydrate LiClO3·3H2O was slowly added under high-speed dispersion (speed of 8000 rpm) and stirred for 3 hours to form a stable oil-in-water emulsion; 1.5 g of dibutyltin diacetate catalyst was added to the emulsion, stirred evenly, and then poured into a mold. After curing at 80°C for 18 hours, a self-healing flexible phase change energy storage material was obtained.

[0063] Example 4

[0064] This embodiment provides a method for preparing a self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system, comprising the following steps:

[0065] 159.1g of amino silicone oil (-NH2 content of 0.9wt%), 29.8g of isophorone diisocyanate, 11.1g of 4,4'-diaminodiphenyl disulfide, and 3g of polysorbate 80 were added to a high-speed disperser. After heating to 80°C, 100g of molten ferric chloride hexahydrate FeCl3·6H2O was slowly added under high-speed dispersion (speed of 5000rpm) and stirred for 2h to form a stable oil-in-water emulsion; 1.2g of dibutyltin diosilicate was added to the emulsion, stirred evenly, and then poured into a mold. After curing at 60°C for 24h, a self-healing flexible phase change energy storage material was obtained.

[0066] Example 5

[0067] This embodiment provides a method for preparing a self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system, comprising the following steps:

[0068] 79.5 g of amino silicone oil (-NH2 content of 0.9 wt%), 14.9 g of isophorone diisocyanate, 5.6 g of 4,4'-diaminodiphenyl disulfide, and 3 g of sorbitan trioleate were added to a high-speed disperser. After heating to 70°C, 100 g of molten magnesium sulfate heptahydrate MgSO4·7H2O was slowly added under high-speed dispersion (speed of 8000 rpm) and stirred for 1.5 hours to form a stable oil-in-water emulsion; 0.5 g of dibutyltin(dodecylsulfide) was added to the emulsion, stirred evenly, and then poured into a mold. After curing at 40°C for 48 hours, a self-healing flexible phase change energy storage material was obtained.

[0069] Example 6

[0070] This embodiment provides a method for preparing a self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system, comprising the following steps:

[0071] 230.4 g of amino silicone oil (-NH2 content of 0.3 wt%), 14.3 g of isophorone diisocyanate, 5.3 g of 4,4'-diaminodiphenyl disulfide, and 3 g of sorbitan monooleate were added to a high-speed disperser. After heating to 60°C, 100 g of molten disodium hydrogen phosphate dodecahydrate Na2HPO4·12H2O was slowly added under high-speed dispersion (speed of 6000 rpm) and stirred for 2 hours to form a stable oil-in-water emulsion; 1 g of dibutyltin diacetate was added to the emulsion, stirred evenly, and then poured into a mold. The emulsion was cured at 100°C for 12 hours to obtain a self-healing flexible phase change energy storage material.

[0072] Test example

[0073] The performance of the self-repairable flexible phase change energy storage materials obtained in Examples 1-6 was tested. The test results are shown in Table 1. The test method is as follows:

[0074] 1. DSC test: A Perkin-Elmer DSC 8500 differential scanning calorimeter was used. The test temperature and thermal enthalpy were calibrated with high-purity standard indium samples. About 5 mg of sample was accurately weighed. The atmosphere was N2 (flow rate was 20 mL / min), the heating rate was 10°C / min, and the scanning range was from 10 to 70°C.

[0075] 2. Mechanical properties test: A universal mechanical testing machine from Istron, USA, was used with a tensile rate of 30 mm / min, equipped with a 200 N load cell, and sample size: 30 mm × 10 mm × 2 mm.

[0076] Table 1 Product performance test

[0077] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Phase transition point (temperature) 29.2℃ 33.3℃ 8.1℃ 37.4℃ 48.6℃ 38.7℃ Phase change enthalpy 95.3J / g 152.8J / g 42.7J / g 74.3J / g 101.7 J / g 79.6J / g Elongation at break 286％ 215％ 396％ 315％ 284％ 369％ fracture stress 2.07MPa 1.76MPa 2.43MPa 2.28MPa 2.04MPa 2.52MPa

[0078] Combined with the above data, it can be seen that the phase change energy storage material of the present invention has excellent flexibility, thermal stability and energy storage density; among them, Example 1 has the best comprehensive indicators.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made by any technician familiar with the field within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system, characterized by: Including continuous phase, dispersed phase and additives; The continuous phase is modified amino silicone oil, and the modified amino silicone oil includes isophorone diisocyanate, 4,4'-diaminodiphenyl disulfide and amino silicone oil; The dispersed phase includes an inorganic phase change material; The auxiliary agents include emulsifiers and catalysts.

2. The self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system according to claim 1, characterized in that: The inorganic phase change material is a crystalline hydrated salt material.

3. The self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system according to claim 2, characterized in that: The inorganic phase change material is at least one of Na2SO4·10H2O, Mn(NO3)2·6H2O, Na2HPO4·12H2O, CaCl2·6H2O, Na2CO3·10H2O, LiClO3·3H2O, FeCl3·6H2O, and MgSO4·7H2O.

4. The self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system according to claim 1, characterized in that: The amino silicone oil has a 3-aminopropyl functional group and the -NH2 content of the amino silicone oil is 0.23 to 0.9 wt%.

5. The self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system according to claim 1, characterized in that: The mass ratio of the amino silicone oil, isophorone diisocyanate and 4,4'-diaminodiphenyl disulfide is (14-64): (1.3-3.1):

1.

6. The self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system according to claim 1, characterized in that: The emulsifier is at least one of sorbitan monooleate, sorbitan trioleate, polysorbate 80, polysorbate-20, PEG-10 polydimethylsiloxane, and cetyl polyethylene glycol / polypropylene glycol-10 / 1 dimethylsiloxane copolymer; the amount of the emulsifier used is 2% to 5% of the mass of the inorganic phase change material.

7. The self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system according to claim 1, characterized in that: The catalyst is an organic tin catalyst, which includes at least one of dibutyltin dilaurate, dibutyltin didodecylsulfide and dibutyltin diacetate. The amount of the organic tin catalyst is 0.3% to 0.6% of the mass of the modified amino silicone oil.

8. The self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system according to claim 1, characterized in that: The mass ratio of the inorganic phase change material to the modified amino silicone oil is 1:0.7-5.

9. A method for preparing a self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Add amino silicone oil, isophorone diisocyanate, 4,4'-diaminodiphenyl disulfide, and emulsifier into a high-speed disperser with a stirring speed of 2000-8000 rpm and a reaction temperature of 20-80°C. Slowly add the molten inorganic phase change material under high-speed dispersion and keep stirring for 0.5-3 hours to form a stable water-in-oil emulsion; S2. Add a catalyst to the water-in-oil emulsion, stir evenly, pour the emulsion into a mold, and cure it at 40-100°C for 12-48 hours to obtain a self-repairable flexible phase change energy storage material.

10. A method for preparing a self-repairable flexible phase change energy storage material based on a water-in-oil emulsion system according to claim 9, characterized in that: The self-repairable flexible phase change energy storage material is a pod-shaped flexible phase change material.

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