Self-repairing sealant based on ionic clusters as well as preparation method and application of self-repairing sealant

Abstract

The invention belongs to the technical field of photovoltaic device packaging, and relates to a self-repairing sealant based on ionic clusters and a preparation method and application thereof. The method comprises the following steps: dissolving N-vinyl imidazole and alkoxy bromide in dimethyl sulfoxide, and carrying out alkyl substitution reaction to obtain a mixed solution A; cooling the mixed solution A, adding ethyl acetate, standing for layering, dissolving a lower-layer crude product in water, washing, and drying to obtain a viscous liquid; dissolving the viscous liquid and a lithium salt in deionized water, and carrying out an ion exchange reaction to obtain a precipitate B; washing and drying the precipitate B to obtain a precipitate C; dissolving the precipitate C in dimethyl sulfoxide, adding an initiator, and carrying out a free radical polymerization reaction to obtain a mixed solution D; cooling the mixed solution D, then adding ethyl acetate, standing for layering, dissolving a lower-layer crude product in water, washing and drying to obtain the self-repairing sealant, which has the advantage of rapid low-temperature self-healing and can realize lossless packaging.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic device packaging, and relates to a self-repairing sealant based on ion clusters, and a preparation method and application thereof. Background Art

[0002] The encapsulation of photovoltaic devices is crucial for ensuring their long-term stable operation. Encapsulation materials must effectively block moisture and oxygen permeation, and protect against UV radiation, temperature and humidity fluctuations, and mechanical stress, thereby ensuring the module's photovoltaic conversion efficiency and service life. Currently, mainstream encapsulation materials include ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), silicone, and polyurethane. EVA dominates the market due to its low cost and excellent adhesion, but it suffers from drawbacks such as hydrolysis and yellowing. While POE offers excellent weather resistance and barrier properties, it faces processing difficulties and high costs. Silicone and polyurethane materials are limited by insufficient adhesion and poor high-temperature resistance. Furthermore, with the long-term use of photovoltaic modules in complex outdoor environments, encapsulation materials must continuously withstand harsh conditions such as mechanical stress, temperature fluctuations, and UV radiation. Traditional encapsulation materials are prone to performance degradation due to the accumulation of microscopic damage over time, leading to reduced module efficiency or even failure.

[0003] To meet the durability requirements of packaging materials, self-healing technology is seen as a potential breakthrough. Existing self-healing systems are mostly based on dynamic covalent bonds or supramolecular interactions (such as hydrogen bonds and host-guest interactions). While these systems can achieve certain repair functions, the repair process typically relies on external stimuli such as high temperature and light, and can take hours to days. This makes it difficult to meet the urgent need for rapid, autonomous repair of photovoltaic modules in complex outdoor environments.

[0004] Therefore, how to develop sealant packaging materials with rapid low-temperature self-healing while meeting the packaging performance requirements is a key problem that needs to be solved urgently in the current photovoltaic device field. Summary of the Invention

[0005] To solve the problems in the prior art, the present invention provides a self-repairing sealant based on ion clusters, a preparation method and application thereof, which has the advantages of rapid low-temperature self-healing and realizes lossless packaging.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a method for preparing a self-repairing sealant based on ion clusters, comprising the following steps: S1: N-vinylimidazole and alkoxy bromide are dissolved in dimethyl sulfoxide to undergo an alkyl substitution reaction to obtain a mixed solution A; ethyl acetate is added to the mixed solution A after cooling, and the solution is allowed to stand to separate layers; the crude product in the lower layer is dissolved in water, washed, and dried to obtain a viscous liquid; S2: dissolving the viscous liquid and lithium salt in deionized water to perform an ion exchange reaction to obtain a precipitate B; washing and drying the precipitate B to obtain a precipitate C; S3: dissolving the precipitate C in dimethyl sulfoxide, adding an initiator, and conducting a free radical polymerization reaction to obtain a mixed solution D; after the mixed solution D is cooled, ethyl acetate is added, and the mixed solution is allowed to stand to separate into layers, and the crude product in the lower layer is dissolved in water, and after washing and drying, the self-healing sealant based on ion clusters is obtained.

[0007] Preferably, the molar ratio of the N-vinylimidazole to the alkoxy bromide is 1:(1-2).

[0008] Preferably, the molar ratio of the viscous liquid to the lithium salt is 1:(1-2).

[0009] Preferably, the mass of the initiator is 1% to 3% of the mass of the precipitate.

[0010] Preferably, the alkoxy bromide is 1-(2-(2-ethoxyethoxy)ethyl) bromide.

[0011] Preferably, the lithium salt is lithium bis(trifluoromethylsulfonyl)imide.

[0012] Preferably, the photoinitiator is azobisisobutyronitrile.

[0013] Preferably, the reaction conditions of the alkyl substitution reaction are: stirring the reaction at 70-90°C for 24-48 hours; the reaction conditions of the ion exchange reaction are: stirring the reaction at 20-30°C for 6-12 hours; and the reaction conditions of the free radical polymerization reaction are: stirring the reaction at 70-90°C for 12-24 hours.

[0014] In a second aspect, the present invention provides a self-healing sealant based on ion clusters.

[0015] In a third aspect, the present invention provides an application of a self-repairing sealant based on ion clusters in the field of photovoltaic device packaging technology, comprising the following steps: heating the self-repairing sealant based on ion clusters and uniformly coating it on the cover glass; covering the cover glass on the surface of the solar photovoltaic device to be encapsulated, applying pressure and maintaining it for a preset time, and standing it until the sealant is completely cured to obtain an encapsulated solar photovoltaic device.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention introduces dynamically reversible ion cluster structures into the sealant packaging material. This technology leverages the highly tunable, easily aggregated, and highly reversible nature of ion clusters to significantly accelerate their association and dissociation, endowing the packaging material with rapid self-healing properties. Furthermore, by restricting the free movement of adjacent molecular chains and acting as physical crosslinking points, the ion clusters enhance the mechanical strength and interfacial stability of the sealant packaging material, reducing the probability of damage to photovoltaic devices due to stress concentration or environmental erosion. This invention not only simplifies the maintenance process for packaged devices, but also significantly reduces costs and increases the service life of packaged devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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 therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is an electron microscope image of the self-repairing sealant based on ion clusters of the present invention; Figure 2 is a diagram of the self-repairing process of the self-repairing sealant of the present invention; Figure 3 This is a graph showing the change in photoelectric conversion efficiency of perovskite solar cells before and after encapsulation; Figure 4 This is a stability test chart of damaged and undamaged perovskite solar cells encapsulated with the self-repairing sealant of the present invention under hot and humid conditions. DETAILED DESCRIPTION

[0019] To facilitate understanding of the features and effects of the present invention by those skilled in the art, the following provides a general description and definition of the terms and expressions used in the specification and claims. Unless otherwise indicated, all technical and scientific terms used herein have the ordinary meanings as understood by those skilled in the art regarding the present invention. In the event of conflict, the definitions in this specification shall prevail.

[0020] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0021] All features, such as values, amounts, contents, and concentrations, described herein as numerical ranges or percentage ranges are provided for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to include and specifically disclose all possible subranges and individual values within the range (including integers and fractions).

[0022] In this document, unless otherwise specified, “include,” “including,” “contains,” “has” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0023] In this document, for the sake of brevity, not all possible combinations of the various technical features in each embodiment or example are described. Therefore, as long as there are no contradictions in the combination of these technical features, the various technical features in each embodiment or example can be combined in any way, and all possible combinations should be considered to be within the scope of this specification.

[0024] The present invention is described in further detail below with reference to the accompanying drawings: The first object of the present invention is to provide a method for preparing a self-repairing sealant based on ion clusters, comprising the following steps: S1: Dissolve N-vinylimidazole and alkoxy bromide in dimethyl sulfoxide in a molar ratio of 1:(1-2) and stir at 70-90°C for 24-48 hours to carry out an alkyl substitution reaction to obtain a mixed solution A. After the mixed solution A is cooled, ethyl acetate is added and allowed to stand to separate layers. The crude product in the lower layer is dissolved in water, washed with ethyl acetate, and dried to obtain a viscous liquid. S2: dissolving the viscous liquid and lithium salt in a molar ratio of 1:(1-2) in deionized water, stirring and reacting at 20-30°C for 6-12 hours to perform an ion exchange reaction to obtain a precipitate B; washing and drying the precipitate B to obtain a precipitate C; S3: The precipitate C is dissolved in dimethyl sulfoxide, and an initiator accounting for 1% to 3% of the mass of the precipitate is added, and the mixture is stirred and reacted at 70 to 90°C for 12 to 24 hours to perform a free radical polymerization reaction to obtain a mixed solution D; after the mixed solution D is cooled, ethyl acetate is added, and the mixture is allowed to stand to separate into layers, and the crude product in the lower layer is dissolved in water, washed with ethyl acetate, and dried to obtain the self-healing sealant based on ion clusters.

[0025] In this invention, N-vinylimidazole serves as the primary monomer, with its imidazole ring providing coordination sites and vinyl groups participating in polymerization. Alkoxy bromides introduce functional side chains through alkyl substitution reactions. Lithium salts form dynamic ion pairs through ion exchange, and an initiator induces free radical polymerization to form a polymer network. Through a three-step reaction (alkyl substitution, ion exchange, and free radical polymerization), the invention introduces a dynamically reversible ion cluster structure into the sealant encapsulant. The anions and cations (imidazole anions and lithium cations) in the polymer (sealant) aggregate through strong electrostatic interactions to form ion clusters, which are dispersed within the polymer matrix. This approach leverages the highly tunable, easily aggregated, and highly reversible nature of ion clusters to significantly accelerate the association-dissociation process within the sealant, imparting rapid self-healing properties to the encapsulant. Furthermore, by restricting the free movement of adjacent molecular chains and acting as physical crosslinking points, the ion clusters enhance the mechanical strength and interfacial stability of the sealant encapsulant, reducing the likelihood of damage to photovoltaic devices due to stress concentration or environmental erosion. When the sealant is subjected to different environments and strain forces and cracks are generated, that is, when it breaks, the electrostatic binding force between anions and cations in the sealant material weakens, causing the ions to dissociate from their original ion clusters and migrate to the crack interface to provide charge compensation and form new ion pairs or ion clusters. At the same time, the polymer chain segments covalently linked to the ionic groups diffuse into the crack area under the action of ion migration, filling the crack gaps to maintain the stability of the mechanical properties before and after repair.

[0026] The alkoxy bromide is 1-(2-(2-ethoxyethoxy)ethyl) bromide, which has high reactivity and can ensure the rapid completion of the alkyl substitution reaction. At the same time, the moderate chain length structure achieves a balance between reactivity and flexibility, so that the sealant has both efficient self-healing properties and excellent mechanical strength.

[0027] The lithium salt lithium bis(trifluoromethylsulfonyl)imide has good ion dissociation ability and cost advantages, can form a stable ion cluster network, and enables the sealant to achieve rapid self-repair; at the same time, it has excellent chemical stability and hydrophobicity, and is suitable for photovoltaic packaging in high humidity environments.

[0028] The photoinitiator is azobisisobutyronitrile, etc., which can ensure that the free radical polymerization proceeds smoothly and avoids violent polymerization.

[0029] The second object of the present invention is to provide a self-healing sealant based on ion clusters, which enables the packaging material to complete active self-healing in a short time and at low temperature through the association-dissociation characteristics of ion clusters. This not only simplifies the maintenance process of the packaging device, but also greatly reduces the cost and improves the service life of the packaging device.

[0030] The third object of the present invention is to provide an application of a self-repairing sealant based on ion clusters in the field of photovoltaic device packaging technology, comprising the following steps: heating the self-repairing sealant based on ion clusters at 90-120°C for 2 minutes and then evenly coating it on the cover glass; covering the cover glass on the surface of the solar photovoltaic device to be encapsulated, applying a pressure of 30KPa and maintaining it for 3 minutes, and standing at room temperature until the sealant is completely cured to obtain an encapsulated solar photovoltaic device.

[0031] The self-healing sealant based on ion clusters provided by this invention, with its unique dynamic ion network structure, imparts self-healing capabilities to the packaging system, enabling devices to maintain stable photoelectric conversion efficiency over long periods of time even in extreme hot and humid environments. Compared to traditional packaging technologies, this sealant not only significantly reduces the impact of the packaging process on device performance but also can self-repair after external mechanical damage, effectively preventing environmental erosion of the device. This significantly extends the service life of photovoltaic devices under harsh operating conditions and has broad market application prospects.

[0032] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0033] The following examples were prepared using conventional instruments and equipment in the art. Experimental methods in the following examples, where specific conditions are not specified, were generally performed under conventional conditions or according to the conditions recommended by the manufacturer. The various raw materials used in the following examples, unless otherwise specified, were conventional commercially available products, with specifications conventional in the art. In the present specification and the following examples, unless otherwise specified, "%" indicates percentage by weight, "part" indicates parts by weight, and "ratio" indicates weight ratio.

[0034] Example 1 At room temperature, 0.1 mol of N-vinylimidazole was dissolved in 50 mL of dimethyl sulfoxide. 0.1 mol of 1-(2-(2-ethoxyethoxy)ethyl)bromide was added to the reaction system, and the mixture was stirred at 90°C for 24 h. After the mixed solution was cooled to room temperature, ethyl acetate was added. The mixed solution separated into layers. The crude product in the lower layer was dissolved in water, washed five times with ethyl acetate, and dried under vacuum at 60°C for 24 h to obtain 1-(2-(2-ethoxyethoxy)ethyl)-3-vinylimidazole bromide.

[0035] Dissolve 0.05 mol of the aforementioned 1-(2-(2-ethoxyethoxy)ethyl)-3-vinylimidazolium bromide (6 g) in 80 mL of deionized water. Add 0.05 mol of lithium bis(trifluoromethylsulfonyl)imide to the reaction system and stir at 25°C for 9 h to obtain a precipitate. Wash the precipitate five times with deionized water and vacuum dry at 65°C for 24 h to obtain 1-(2-(2-ethoxyethoxy)ethyl)-3-vinylimidazolium bis(trifluoromethylsulfonyl)imide salt.

[0036] The above-mentioned 1-(2-(2-ethoxyethoxy)ethyl)-3-vinylimidazole bis(trifluoromethanesulfonyl)imide salt (4 g) was dissolved in 50 mL of dimethyl sulfoxide. Azobisisobutyronitrile (0.04 g) was added to the reaction system, and the mixture was stirred at 80°C for 18 hours. After the mixed solution was cooled to room temperature, ethyl acetate was added. The mixed solution separated into two layers. The crude product in the lower layer was washed five times with ethyl acetate and dried in vacuo at 60°C for 24 hours to obtain a polymerized 1-(2-(2-ethoxyethoxy)ethyl)-3-vinylimidazole bis(trifluoromethanesulfonyl)imide sealant.

[0037] The self-healing sealant is heated at 90°C for 2 minutes and then applied to cut glass. The cover glass coated with the sealant is then placed over the surface of the perovskite solar cell to be encapsulated. The sealant is maintained at a pressure of 30 kPa for 3 minutes and then allowed to stand at room temperature until the sealant is fully cured, resulting in an encapsulated solar photovoltaic device. Solar cells can heat up during normal operation and easily exceed 50°C. The sealant can self-heal after just 10 minutes at 50°C.

[0038] Test results: The device efficiency before packaging was 22.19%, and the efficiency after packaging was 21.73%. The complete packaged device was subjected to 85% relative humidity and 85°C damp heat conditions for 500 hours. Then, the edge sealant of the packaged device was artificially damaged. Due to its rapid self-repair ability, the damaged packaged device still maintained its initial efficiency of 90.3% after the subsequent 500-hour damp heat test.

[0039] Example 2 At room temperature, 0.1 mol of N-vinylimidazole was dissolved in 50 mL of dimethyl sulfoxide. 0.15 mol of 1-(2-(2-ethoxyethoxy)ethyl)bromide was added to the reaction system, and the mixture was stirred at 80°C for 36 hours. After the mixed solution was cooled to room temperature, ethyl acetate was added. The mixed solution separated into layers. The crude product in the lower layer was dissolved in water, washed five times with ethyl acetate, and dried in vacuo at 60°C for 24 hours to obtain 1-(2-(2-ethoxyethoxy)ethyl)-3-vinylimidazole bromide.

[0040] Dissolve 0.05 mol of the aforementioned 1-(2-(2-ethoxyethoxy)ethyl)-3-vinylimidazolium bromide in 80 mL of deionized water. Add 0.075 mol of lithium bis(trifluoromethylsulfonyl)imide to the reaction system and stir at 20°C for 12 hours to obtain a precipitate. Wash the precipitate five times with deionized water and vacuum dry at 65°C for 24 hours to obtain 1-(2-(2-ethoxyethoxy)ethyl)-3-vinylimidazolium bis(trifluoromethylsulfonyl)imide salt.

[0041] The above-mentioned 1-(2-(2-ethoxyethoxy)ethyl)-3-vinylimidazole bis(trifluoromethanesulfonyl)imide salt (4 g) was dissolved in 50 mL of dimethyl sulfoxide. Azobisisobutyronitrile (0.08 g) was added to the reaction system, and the mixture was stirred at 70°C for 24 hours. After the mixed solution was cooled to room temperature, ethyl acetate was added. The mixed solution separated into two layers. The crude product in the lower layer was washed five times with ethyl acetate and dried in vacuo at 60°C for 24 hours to obtain a polymerized 1-(2-(2-ethoxyethoxy)ethyl)-3-vinylimidazole bis(trifluoromethanesulfonyl)imide sealant.

[0042] The self-healing sealant was heated at 100°C for 2 minutes and then applied to cut glass. The cover glass coated with the sealant was then placed over the surface of the perovskite solar cell to be encapsulated. The sealant was maintained at a pressure of 30 kPa for 3 minutes, and then allowed to stand at room temperature for 3 minutes until the sealant was fully cured, resulting in the encapsulated solar photovoltaic device. During normal operation, solar cells can heat up and easily exceed 50°C. The sealant was able to self-heal after just 6 minutes at 50°C.

[0043] Test results: The device efficiency before packaging was 22.15%, and the efficiency after packaging was 22.11%. The complete packaged device was subjected to 85% relative humidity and 85°C damp heat conditions for 500 hours. Then, the edge sealant of the packaged device was artificially damaged. Due to its rapid self-repair ability, the damaged packaged device still maintained its initial efficiency of 92.8% after the subsequent 500-hour damp heat test.

[0044] Example 3 At room temperature, 0.1 mol of N-vinylimidazole was dissolved in 50 mL of dimethyl sulfoxide. 0.2 mol of 1-(2-(2-ethoxyethoxy)ethyl)bromide was added to the reaction system, and the mixture was stirred at 70°C for 48 hours. After the mixed solution was cooled to room temperature, ethyl acetate was added. The mixed solution separated into layers. The crude product in the lower layer was dissolved in water, washed five times with ethyl acetate, and dried in vacuo at 60°C for 24 hours to obtain 1-(2-(2-ethoxyethoxy)ethyl)-3-vinylimidazole bromide.

[0045] Dissolve 0.05 mol of the aforementioned 1-(2-(2-ethoxyethoxy)ethyl)-3-vinylimidazolium bromide in 80 mL of deionized water. Add 0.10 mol of lithium bis(trifluoromethylsulfonyl)imide to the reaction system and stir at 30°C for 6 h to obtain a precipitate. Wash the precipitate five times with deionized water and vacuum dry at 65°C for 24 h to obtain 1-(2-(2-ethoxyethoxy)ethyl)-3-vinylimidazolium bis(trifluoromethylsulfonyl)imide salt.

[0046] The above-mentioned 1-(2-(2-ethoxyethoxy)ethyl)-3-vinylimidazole bis(trifluoromethanesulfonyl)imide salt (4 g) was dissolved in 50 mL of dimethyl sulfoxide. Azobisisobutyronitrile (0.12 g) was added to the reaction system, and the mixture was stirred at 90°C for 12 hours. After the mixed solution was cooled to room temperature, ethyl acetate was added. The mixed solution separated into two layers. The crude lower layer was washed five times with ethyl acetate and dried under vacuum at 60°C for 24 hours to obtain a polymerized 1-(2-(2-ethoxyethoxy)ethyl)-3-vinylimidazole bis(trifluoromethanesulfonyl)imide sealant.

[0047] The self-healing sealant was heated at 120°C for 2 minutes and then applied to cut glass. The cover glass coated with the sealant was then placed over the surface of the perovskite solar cell to be encapsulated. The sealant was maintained at a pressure of 30 kPa for 3 minutes, and then allowed to stand at room temperature for 3 minutes until the sealant was fully cured, resulting in the encapsulated solar photovoltaic device. During normal operation, solar cells can heat up and easily exceed 50°C. The sealant self-healed after 20 minutes at 50°C.

[0048] Test results: The device efficiency before packaging was 22.05%, and the efficiency after packaging was 21.68%. The complete packaged device was subjected to 85% relative humidity and 85°C damp heat conditions for 500 hours. Then, the edge sealant of the packaged device was artificially damaged. Due to its rapid self-repair ability, the damaged packaged device still maintained its initial efficiency of 84.6% after the subsequent 500-hour damp heat test.

[0049] Figure 1 This is an electron microscope image of the self-repairing sealant based on ion clusters prepared in Example 1 of the present invention. It can be seen that the anions and cations in the sealant polymer aggregate to form ion clusters through strong electrostatic interactions.

[0050] Figure 2 This is an optical microscope image of the self-repairing process of the self-repairing sealant prepared in Example 1 of the present invention at 50°C. It can be seen that the sealant of the present invention can achieve self-healing at 50°C.

[0051] like Figure 3As shown, the perovskite device encapsulated with the self-repairing sealant prepared in Example 1 of the present invention does not show significant efficiency degradation before and after encapsulation compared with the unencapsulated perovskite device, which shows that the process of the present invention can achieve lossless encapsulation.

[0052] Figure 4 This is a stability test of damaged and undamaged perovskite solar cells encapsulated with the self-repairing sealant of Example 1 of the present invention during a wet heat test. Specifically, undamaged means that the encapsulated device remains intact during the 1000 h of the wet heat test, and damaged means that the encapsulated device remains intact during the initial 500 h of the wet heat test. Then, the sealant on one side of the device is artificially damaged, and then a subsequent 500 h wet heat stability test is performed.

[0053] Test results show that the device efficiency decay of perovskite cells before and after encapsulation is ≤0.5%, and the fully encapsulated devices survived 500 hours under 85% relative humidity and 85°C damp heat conditions. The rapid self-repair ability of the damaged edge sealant of the encapsulated device allowed the damaged device to maintain 85%-93% of its initial efficiency after a subsequent 500-hour damp heat test. In comparison, conventional encapsulation processes result in an efficiency loss of 3%-5%, and under the same damp heat test conditions, the efficiency of the damaged conventionally encapsulated device decreased by approximately 50% after 744 hours. This invention achieves safe and long-life operation of photovoltaic devices, has outstanding industrial potential, and provides important support for accelerating the commercial application of perovskite photovoltaic technology.

[0054] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a self-repairing sealant based on ion clusters, characterized in that: The following steps are involved: S1: N-vinylimidazole and alkoxy bromide are dissolved in dimethyl sulfoxide to undergo an alkyl substitution reaction to obtain a mixed solution A; ethyl acetate is added to the mixed solution A after cooling, and the solution is allowed to stand to separate layers; the crude product in the lower layer is dissolved in water, washed, and dried to obtain a viscous liquid; S2: dissolving the viscous liquid and lithium salt in deionized water to perform an ion exchange reaction to obtain a precipitate B; washing and drying the precipitate B to obtain a precipitate C; S3: dissolving the precipitate C in dimethyl sulfoxide, adding an initiator, and conducting a free radical polymerization reaction to obtain a mixed solution D; after the mixed solution D is cooled, ethyl acetate is added, and the mixed solution is allowed to stand to separate into layers, and the crude product in the lower layer is dissolved in water, and after washing and drying, the self-healing sealant based on ion clusters is obtained.

2. The method for preparing a self-repairing sealant based on ion clusters according to claim 1, characterized in that: The molar ratio of the N-vinylimidazole to the alkoxy bromide is 1:(1-2).

3. The method for preparing a self-repairing sealant based on ion clusters according to claim 1, characterized in that: The molar ratio of the viscous liquid to the lithium salt is 1:(1-2).

4. The method for preparing a self-repairing sealant based on ion clusters according to claim 1, characterized in that: The mass of the initiator is 1% to 3% of the mass of the precipitate.

5. The method for preparing a self-repairing sealant based on ion clusters according to claim 1, characterized in that: The alkoxy bromide is 1-(2-(2-ethoxyethoxy)ethyl) bromide.

6. The method for preparing a self-repairing sealant based on ion clusters according to claim 1, characterized in that: The lithium salt is lithium bis(trifluoromethylsulfonyl)imide.

7. The method for preparing a self-repairing sealant based on ion clusters according to claim 1, characterized in that: The photoinitiator is azobisisobutyronitrile.

8. The method for preparing a self-repairing sealant based on ion clusters according to claim 1, characterized in that: The reaction conditions of the alkyl substitution reaction are: stirring the reaction at 70-90° C. for 24-48 hours; the reaction conditions of the ion exchange reaction are: stirring the reaction at 20-30° C. for 6-12 hours; and the reaction conditions of the free radical polymerization reaction are: stirring the reaction at 70-90° C. for 12-24 hours.

9. A self-repairing sealant based on ion clusters, characterized in that: The method is prepared according to any one of claims 1 to 8.

10. Application of the self-repairing sealant based on ion clusters in the field of photovoltaic device packaging technology according to claim 9, characterized in that: The following steps are involved: The self-healing sealant based on ion clusters is heated and evenly coated on the cover glass; the cover glass is covered on the surface of the solar photovoltaic device to be encapsulated, pressure is applied and maintained for a preset time, and the sealant is allowed to stand until it is completely cured to obtain an encapsulated solar photovoltaic device.

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