In-situ curing gel structure electrolyte and preparation method and application thereof

Abstract

The invention relates to an in-situ curing gel structure electrolyte as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) mixing a resin matrix with a pore-forming agent, then adding a curing agent for mixing to obtain a mixed solution, and pouring the mixed solution into a closed mold for curing to obtain a resin film; soaking and drying the resin film to obtain porous resin; and (2) mixing 4-styrene sulfonyl (phenylsulfonyl) imide lithium salt, polyethylene glycol methyl ether acrylate, polyethylene glycol dimethacrylate, ethylene carbonate and azodiisobutyronitrile to prepare a mixed solution, and soaking the porous resin in the mixed solution to react and cure, thereby obtaining the in-situ curing gel structure electrolyte. The preparation method is simple, and the prepared in-situ curing gel structure electrolyte can improve the mechanical property, the battery capacity and the cycle performance of the in-situ curing gel structure electrolyte.

Description

Technical Field

[0001] The present invention relates to the technical field of solid electrolytes, and in particular to an in-situ solidified gel structure electrolyte and a preparation method and application thereof. Background Art

[0002] Solid-state electrolytes are often considered potential alternatives to traditional liquid electrolytes due to their advantages, including improved safety, stability, a wider operating temperature range, higher energy density, improved cycling performance, and effective suppression of lithium dendrite growth. Solid-state electrolytes can significantly improve battery safety and stability. They are primarily used in the installation and application of solid-state electrolyte batteries and have broad application prospects in a variety of fields, including energy storage, sensor technology, micro- and nanoelectronic devices, automotive manufacturing, and microelectronics.

[0003] Conventional energy storage materials such as structural energy storage composite materials and button batteries using porous resin membranes as separators can only use liquid electrolytes as transmission media, which severely limits the range of options and various functions of the electrolytes. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide an in-situ cured gel structure electrolyte and its preparation method and application. The preparation method of the present invention is simple, and the prepared in-situ cured gel structure electrolyte can improve the mechanical properties, battery capacity and cycle performance of the in-situ cured gel structure electrolyte.

[0005] The technical solution of the present invention to solve the above technical problems is as follows:

[0006] The first object of the present invention is to provide a method for preparing an in-situ solidified gel structure electrolyte, comprising the following steps:

[0007] (1) mixing a resin matrix with a pore-forming agent, and then adding a curing agent to mix to obtain a mixed solution, pouring the mixed solution into a closed mold and curing it to obtain a resin film; soaking the resin film and then drying it to obtain a porous resin;

[0008] (2) 4-styrenesulfonyl (phenylsulfonyl) imide lithium salt, polyethylene glycol methyl ether acrylate, polyethylene glycol dimethacrylate, ethylene carbonate, and azobisisobutyronitrile are mixed to prepare a mixed solution, and the porous resin is immersed in the mixed solution for reaction and solidification, thereby preparing an in-situ solidified gel structure electrolyte.

[0009] The beneficial effects of the present invention are as follows: the polymer is immersed in the porous resin in the monomer state, and is in-situ polymerized and cured to obtain a structural gel electrolyte. The present invention introduces the gel electrolyte into the pore structure, transforms the porous resin into a solid structure of the porous resin-gel electrolyte, and can improve the mechanical properties, battery capacity and cycle performance of the in-situ cured gel structure electrolyte.

[0010] On the basis of the above technical solution, the present invention can also be improved as follows.

[0011] Furthermore, in step (1), the mass ratio of the resin matrix, the pore-forming agent, and the curing agent is 1:2-4:0.1-0.7;

[0012] The resin matrix is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, special resin, and multifunctional resin; the curing agent is an amine curing agent; and the pore-forming agent is at least one of polyethylene glycol, glucose, ethylene carbonate (EC), and N,N-dimethylformamide (DMF).

[0013] Furthermore, the mass ratio of the 4-styrenesulfonyl (phenylsulfonyl) imide lithium salt, the polyethylene glycol methyl ether acrylate, the polyethylene glycol dimethacrylate, ethylene carbonate, and the azobisisobutyronitrile is 0.3-0.5: 0.6-0.8: 0.2-0.4: 1.4-1.6: 2-4×10 -3 .

[0014] Furthermore, the curing temperature in step (2) is 65-75° C. and the curing time is 10-14 hours.

[0015] Furthermore, the preparation method of the 4-styrenesulfonyl (phenylsulfonyl) imide lithium salt comprises the following steps:

[0016] S1. Mixing anhydrous acetonitrile, sodium 4-styrenesulfonate, and N,N-dimethylformamide to obtain a mixture A, adding oxalyl chloride to the mixture A, stirring, and filtering to obtain a filtrate; concentrating the filtrate by rotary evaporation to obtain a concentrated solution, and adding anhydrous acetonitrile to the concentrated solution to obtain an anhydrous acetonitrile solution of 4-styrenesulfonyl chloride;

[0017] S2, trifluoromethylsulfonamide, 4-dimethylaminopyridine and triethylamine were sequentially added to anhydrous acetonitrile to dissolve to obtain a mixture B, the mixture B was cooled, and an anhydrous acetonitrile solution of 4-styrenesulfonyl chloride was added to obtain a reaction mixture, and then the reaction mixture was kept at a low temperature for a period of time, stirred at room temperature, and finally rotary evaporated to obtain a brown substance; the brown substance was dissolved in dichloromethane, washed and purified, and dichloromethane was added again to dissolve, and rotary evaporated to obtain a viscous brown liquid;

[0018] S3, K2CO3 and the viscous brown liquid are stirred and reacted, and then vacuum dried to obtain lithium 4-styrenesulfonyl (trifluoromethylsulfonyl) imide; the lithium 4-styrenesulfonyl (trifluoromethylsulfonyl) imide and lithium perchlorate are reacted in CH3CN, and rotary evaporation is performed to obtain lithium 4-styrenesulfonyl (phenylsulfonyl) imide.

[0019] Furthermore, the mass parts of the raw materials in step S1 are specifically as follows: the usage ratio of the anhydrous acetonitrile, the oxalyl chloride, the N,N-dimethylformamide, and the sodium salt of 4-styrenesulfonate is 110-130 ml: 5-8 ml: 0.1-0.4 g: 10-14 g.

[0020] Furthermore, the mass fractions of the raw materials in step S2 are specifically as follows: the usage ratio of the trifluoromethylsulfonamide, the 4-dimethylaminopyridine, the triethylamine, the anhydrous acetonitrile, and the anhydrous acetonitrile solution of 4-styrenesulfonyl chloride is 7-9 g: 0.1-0.8 g: 23-25 ml: 90-110 ml: 8-12 ml.

[0021] Furthermore, in step S3, the usage ratio of the lithium 4-styrenesulfonyl (trifluoromethylsulfonyl) imide, the lithium perchlorate, and the CH3CN is 3-7 g: 1.5-2.5 g: 100-110 ml.

[0022] A second object of the present invention is to provide an in-situ solidified gel structure electrolyte.

[0023] The third object of the present invention is to provide an application of an in-situ solidified gel structure electrolyte, wherein the in-situ solidified gel structure electrolyte is used in the preparation of a battery.

[0024] Furthermore, the battery includes at least one of a button battery and a structural energy storage composite material battery.

[0025] Furthermore, the preparation steps of the structural energy storage composite material battery are specifically as follows:

[0026] (1) mixing a resin matrix with a pore-forming agent, and then adding a curing agent to mix to obtain a mixed solution, pouring the mixed solution into a closed mold and curing it to obtain a resin film; soaking the resin film and then drying it to obtain a porous resin;

[0027] (2) The carbon fiber coated LFP / NCM positive electrode material, glass fiber separator, and carbon fiber coated Gr / LTO negative electrode material were stacked and vacuum bagged. The porous resin and polyethylene glycol 200 were fully stirred at a mass ratio of 1:2-4 for 20-30 minutes, and then 4,4'-diaminodicyclohexylmethane (the mass ratio of porous resin to 4,4'-diaminodicyclohexylmethane was 100:57.5) was added and stirred again for 15-20 minutes. The bubbles were removed by filtration, and the above mixture was introduced into the vacuum bag by vacuum infusion; two-step curing, first heating to 130 ° C for 60 minutes, and then heating to 180 ° C and maintaining for 30 minutes, with a heating rate of 5 ° C / min, and then naturally cooled to room temperature to obtain the cured material. The cured material was removed, soaked in water for 24-48 hours (changing the water every 3-5 hours), and then dried; finally, a concentration of 1-4 mmol was injected. The 4-styrenesulfonyl (phenylsulfonyl) imide lithium salt solution is assembled with the positive and negative electrodes, sealed, heated for curing, and allowed to stand for 24 to 36 hours to obtain a structural energy storage composite material. DETAILED DESCRIPTION

[0028] The principles and features of the present invention are described below. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention. Where specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in this field or the product instructions are used. Where the manufacturers of the reagents or instruments used are not specified, they are all conventional products that can be purchased through regular channels.

[0029] Example 1: Preparation of in-situ solidified gel structure electrolyte

[0030] Synthesis of 4-styrenesulfonyl (phenylsulfonyl) imide lithium salt:

[0031] (1) Anhydrous acetonitrile, sodium 4-styrenesulfonate, and N,N-dimethylformamide were added to a two-necked flask in a ratio of 120 ml: 12 g: 0.261 g, and stirred uniformly at room temperature under an argon atmosphere. An ice-water bath was added, and 6.0 ml of oxalyl chloride was added dropwise to the mixture, and stirred at room temperature for 24 h to obtain a mixed solution A. The mixed solution A was filtered to remove solid residues to obtain a filtrate, and the filtrate was concentrated to 10 ml using a rotary evaporator to obtain a concentrated solution.

[0032] (2) Trifluoromethylsulfonamide (8.67 g, 58.2 mmol), 4-dimethylaminopyridine DMAP (0.63 g, 5.16 mmol), triethylamine (24.3 ml, 0.174 mmol), and anhydrous acetonitrile (100 ml) were added to a three-necked flask and stirred to dissolve to obtain a mixture B. The treated concentrate was added to the mixture B in an ice-water bath and stirred at room temperature for 48 h. The acetonitrile was removed by rotary evaporation, and the obtained brown solid was dissolved in dichloromethane, washed, and the dichloromethane was evaporated to obtain a viscous brown liquid.

[0033] (3) Prepare an excess of K2CO3 solution with distilled water and stir the viscous brown liquid vigorously in an ice-water bath for 2 hours, filter, remove the filter cake and dry it under vacuum at 50°C to obtain KSTFSI. 4-Styrenesulfonyl (trifluoromethylsulfonyl) imide lithium salt (LiSTFSI) is synthesized by a displacement reaction of KSTFSI and lithium perchlorate (LiClO4) in CH3CN. In a round-bottom flask, KSTFSI (6.8 g, 0.019 mol) was added to CH3CN (100 ml), followed by LiClO4 (2.05 g, 0.019 mol), and stirred at room temperature overnight to obtain a mixed solution. After cooling, the precipitated LiClO4 was filtered off, and the solvent was removed by rotary evaporation to obtain a white solid. The residual trace solvent was evaporated under vacuum conditions at 40° C. overnight, and the solvent was removed using a rotary evaporator (IKARV10; IKA). The obtained solid was weighed to obtain 4-styrenesulfonyl (phenylsulfonyl) imide lithium salt.

[0034] Preparation of in-situ solidified gel structure electrolyte:

[0035] (1) Tetrafunctional 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane (McLean) and PEG200 (McLean) were mixed and stirred in a mass ratio of 1:3 to form a mixed solution; 4,4'-methylenebis(cyclohexylamine) (a mixture of isomers) epoxy resin curing agent (Aladdin) with a mass of 57.5% of tetrafunctional 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane was added to the mixed solution and stirred to obtain a stirred solution; the stirred solution was poured into a closed mold (length, width and thickness 150mm*150mm*5mm), heated to 130℃ and cured for 60min, then heated to 180℃ and cured for 30min, with a heating rate of 5℃ / min, and then naturally cooled to room temperature to obtain a cured resin film; the resin film was immersed in ultrapure water for 24h and dried for 24h to obtain a porous resin;

[0036] (2) 0.75 g of polyethylene glycol methyl ether acrylate, 0.3 g of polyethylene glycol dimethacrylate, 1.5 g of ethylene carbonate, and 3.75 mg of azobisisobutyronitrile were added to 0.45 g of 4-styrenesulfonyl (phenylsulfonyl) imide lithium salt to prepare a mixed solution, which was then transferred to a conventional 20 mL sample bottle. A porous resin disc weighing about 0.03 g, having a diameter of 12 mm and a thickness of about 0.2 mm was completely immersed in the mixed solution in the conventional 20 mL sample bottle (this mixed solution can completely immerse 6 pieces of the same porous resin discs mentioned above). The solution was allowed to stand for 3-5 hours to allow the electrolyte solution to completely infiltrate the porous resin discs. The gel electrolyte was then heated to cure in situ at a curing temperature of 65-75 ° C and a curing time of 10-14 hours to obtain an in situ cured gel structure electrolyte.

[0037] Example 2: Preparation of in-situ solidified gel structure electrolyte II

[0038] The only difference between this embodiment and embodiment 1 is that in step (1) of preparing the in-situ solidified gel structure electrolyte, the mass ratio of the resin to the pore-forming agent is 1:4, and the remaining steps, conditions and raw materials are the same as those in embodiment 1.

[0039] Example 3: Preparation of structural energy storage composite material

[0040] Preparation of porous resin:

[0041] Tetrafunctional 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane (McLean) and PEG200 (McLean) are mixed and stirred in a mass ratio of 1:3 to form a mixed solution; 4,4'-methylenebis(cyclohexylamine) (a mixture of isomers) epoxy resin curing agent (Aladdin) with a mass of 57.5% of tetrafunctional 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane is added to the mixed solution and stirred to obtain a stirred solution; the stirred solution is poured into a closed mold (length, width and thickness of 150 mm*150 mm*5 mm), heated to 130°C for curing for 60 minutes, and then heated to 180°C for curing for 30 minutes, with a heating rate of 5°C / min, and then naturally cooled to room temperature to obtain a cured resin film; the resin film is immersed in ultrapure water for 24 hours and dried for 24 hours to obtain a porous resin.

[0042] Synthesis of 4-styrenesulfonyl (phenylsulfonyl) imide lithium salt: the same as in Example 1.

[0043] Preparation of structural energy storage composite materials:

[0044] The carbon fiber coated LFP / NCM positive electrode material, glass fiber separator, and carbon fiber coated Gr / LTO negative electrode material were stacked and vacuum bagged. The porous resin and PEG200 were fully stirred at a mass ratio of 1:3 for 20 to 30 minutes. Then 4,4'-diaminodicyclohexylmethane (the mass ratio of porous resin to 4,4'-diaminodicyclohexylmethane was 100:57.5) was added and stirred again for 15 to 20 minutes. The bubbles were removed by filtration and the above mixture was introduced into the vacuum bag by vacuum infusion. ; Two-step curing, first heating to 130℃ for 60min, then heating to 180℃ and maintaining for 30min, with a heating rate of 5℃ / min, then naturally cooling to room temperature to obtain the cured material, removing the cured material, soaking in water for 24 to 48h (changing the water every 3 to 5h); finally injecting a 1.4mmol concentration of 4-styrenesulfonyl (phenylsulfonyl) imide lithium salt solution, assembling and sealing with the positive and negative electrodes, heating for curing, and standing for 24 to 36h to obtain a structural energy storage composite material.

[0045] Example 4: Preparation of structural energy storage composite material II

[0046] The only difference between this embodiment and embodiment 3 is that in the preparation of the structural energy storage composite material, the mass ratio of the resin to the pore-forming agent is 1:4, and the remaining steps, conditions and raw materials are the same as those in embodiment 1.

[0047] Example 5: Preparation of button cells

[0048] A button battery was prepared by a lamination method using LFP\NCM as the positive electrode, Gr\LTO as the negative electrode, and the in-situ gel structure electrolyte prepared in Example 1 as the separator / new solid electrolyte.

[0049] Comparative Example 1: Preparation of reference pure gel

[0050] Synthesis of 4-styrenesulfonyl (phenylsulfonyl) imide lithium salt:

[0051] (1) Anhydrous acetonitrile, sodium 4-styrenesulfonate, and N,N-dimethylformamide were added to a two-necked flask in a ratio of 120 ml: 12 g: 0.261 g, and stirred uniformly at room temperature under an argon atmosphere. An ice-water bath was added, and 6.0 ml of oxalyl chloride was added dropwise to the mixture, and stirred at room temperature for 24 h to obtain a mixed solution A. The mixed solution A was filtered to remove solid residues to obtain a filtrate, and the filtrate was concentrated to 10 ml using a rotary evaporator to obtain a concentrated solution.

[0052] (2) Trifluoromethylsulfonamide (8.67 g, 58.2 mmol), 4-dimethylaminopyridine DMAP (0.63 g, 5.16 mmol), triethylamine (24.3 ml, 0.174 mmol), and anhydrous acetonitrile (100 ml) were added to a three-necked flask and stirred to dissolve to obtain a mixture B. The treated concentrate was added to the mixture B in an ice-water bath and stirred at room temperature for 48 h. The acetonitrile was removed by rotary evaporation, and the obtained brown solid was dissolved in dichloromethane, washed, and the dichloromethane was evaporated to obtain a viscous brown liquid.

[0053] (3) Prepare an excess of K2CO3 solution with distilled water and stir the viscous brown liquid vigorously in an ice-water bath for 2 hours, filter, remove the filter cake and dry it under vacuum at 50°C to obtain KSTFSI. 4-Styrenesulfonyl (trifluoromethylsulfonyl) imide lithium salt (LiSTFSI) is synthesized by a displacement reaction of KSTFSI and lithium perchlorate (LiClO4) in CH3CN. In a round-bottom flask, KSTFSI (6.8 g, 0.019 mol) was added to CH3CN (100 ml), followed by LiClO4 (2.05 g, 0.019 mol), and stirred at room temperature overnight to obtain a mixed solution. After cooling, the precipitated LiClO4 was filtered off, and the solvent was removed by rotary evaporation to obtain a white solid. The residual trace solvent was evaporated under vacuum conditions at 40° C. overnight, and the solvent was removed using a rotary evaporator (IKARV10; IKA). The obtained solid was weighed to obtain 4-styrenesulfonyl (phenylsulfonyl) imide lithium salt.

[0054] Preparation of pure reference gel:

[0055] In a round-bottom flask, 0.45 g of 4-styrenesulfonyl (phenylsulfonyl) imide lithium salt, 0.75 g of polyethylene glycol methyl ether acrylate, 0.3 g of polyethylene glycol dimethacrylate, 1.5 g of ethylene carbonate, and 3.75 mg of azobisisobutyronitrile were added and mixed to prepare a mixed solution. A small porous resin disc weighing about 0.03 g, with a diameter of 12 mm and a thickness of about 0.2 mm was completely immersed in the mixed solution in a conventional 20 mL sample bottle and maintained at 70°C for 12 h to obtain a reference pure gel.

[0056] Comparative Example 2: Preparation of pure porous resin

[0057] Tetrafunctional 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane (McLean) and PEG200 (McLean) are mixed and stirred in a mass ratio of 1:3 to form a mixed solution; 4,4'-methylenebis(cyclohexylamine) (a mixture of isomers) epoxy resin curing agent with a mass of 57.5% of the resin matrix is added to the mixed solution and stirred to obtain a stirred solution; the stirred solution is poured into a closed mold with a size of 150mm*150mm*5mm for curing, and the two-step curing is first heated to 130°C for 60min, and then heated to 180°C and maintained for 30min, with a heating rate of 5°C / min, and then naturally cooled to room temperature to obtain a cured material, and the cured material is removed to obtain a cured resin film; the resin film is immersed in ultrapure water for 24h, and then dried for 24h to obtain a porous resin.

[0058] Comparative Example 3: Preparation of pure porous resin

[0059] The only difference between this comparative example and comparative example 1 is that in the preparation of pure porous resin, the mass ratio of resin to pore-forming agent is 1:4, and the remaining steps, conditions and raw materials are the same as those in comparative example 1.

[0060] Comparative Example 4: Preparation of structural energy storage composite materials

[0061] The carbon fiber coated LFP / NCM positive electrode material, glass fiber separator, and carbon fiber coated Gr / LTO negative electrode material were stacked and vacuum bagged. 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane and polyethylene glycol 200 were fully stirred at a mass ratio of 1:3 for 20 to 30 minutes, and then 4,4'-diaminodicyclohexylmethane (the mass ratio of 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane to 4,4'-diaminodicyclohexylmethane was 100:57.5) was added and stirred again for 15 to 20 minutes. The mixture was vacuum bagged and vacuum bagged. The bubbles were filtered out, and the mixture was then introduced into a vacuum bag by vacuum infusion; two-step curing was performed, first heating to 130°C for 60 minutes, then heating to 180°C and maintaining for 30 minutes, with a heating rate of 5°C / min, and then naturally cooled to room temperature; the cured material was obtained, removed, and soaked in water for 24 to 48 hours (the water was changed every 3 to 5 hours); finally, 266 electrolyte was injected, assembled with the positive and negative electrodes, sealed, heated for curing, and allowed to stand for 24 to 36 hours to obtain a structural energy storage composite material of pure porous resin.

[0062] Comparative Example 5: Preparation of structural energy storage composite materials

[0063] The only difference between this comparative example and comparative example 4 is that in the preparation of the structural energy storage composite material, the mass ratio of the resin to the pore-forming agent is 1:4, and the remaining steps, conditions and raw materials are the same as those in comparative example 1.

[0064] Test Example 1:

[0065] The materials obtained in Examples 1 to 4 and Comparative Examples 1 to 5 were subjected to mechanical property tests. The specific test steps are as follows:

[0066] Comparative Examples 1-3, Examples 1-2: The film materials prepared in Comparative Examples 1-3 and Examples 1-2 were used to prepare tensile test specimens according to the standard GBT1040 for the determination of tensile properties of plastics. The test was performed using an LE5000 series electronic universal testing machine. The specific test method is as follows:

[0067] (1) Place the specimen in the testing machine fixture, ensuring that the clamping area is fully secured and the clamping position is centered. The specimen center axis is aligned with the loading axis to avoid eccentric forces.

[0068] (2) According to the set stretching rate: Stretching rate: the chuck moving speed is 2mm / min.

[0069] (3) Start the testing machine, apply the load, and record the following data: loading force and extensometer or displacement sensor data.

[0070] Examples 3 to 4, Comparative Examples 4 to 5: Prepare tensile test specimens according to the standard ASTM D3039 for composite materials-tensile test methods. The specimens are required to be rectangular and straight-sided. The edges of the specimens must be smooth, free of defects such as cracks, delamination, and burrs. The specimen length is 250 mm, the width is 25 mm, and the thickness is 0.76 mm. In order to prevent the specimen from being damaged during the clamping process of the test fixture, the clamping area usually needs to be pasted with end reinforcement sheets. The thickness of the reinforcement material is 0.13 mm. The reinforcement area usually extends from the end of the specimen to a certain range of the clamping length. The specimen gauge length is 50 mm. Before the test, ensure that the surface of the specimen is clean to avoid dust, grease and other contaminants. The LE5000 series electronic universal testing machine is used for testing. The specific test method is as follows:

[0071] (1) Place the specimen in the testing machine fixture, ensuring that the clamping area is fully secured and the clamping position is centered. The specimen center axis is aligned with the loading axis to avoid eccentric forces.

[0072] (2) According to the set stretching rate: Stretching rate: the chuck moving speed is 2mm / min.

[0073] (3) Start the testing machine, apply the load, and record the following data: loading force and extensometer or displacement sensor data.

[0074] (4) Analyze the data to obtain the image of loading force and displacement, obtain the image data of loading force and displacement and convert it according to formula (1) to obtain the tensile strength of the material:

[0075]

[0076] Table 1 (Unit: MPa)

[0077]

[0078]

[0079] 2. Electrical properties

[0080] The structural energy storage composite materials prepared in Example 3, Example 4, and Comparative Example 4 and Comparative Example 5 were allowed to stand for 24 hours and then subjected to electrochemical testing. The test results are shown in Table 2.

[0081] Table 2

[0082] Specific capacity (mAh / g) 100 turns attenuation (%) Example 3 110.4 10 Example 4 120.6 10 Comparative Example 4 89.2 20 Comparative Example 5 95.5 20

[0083] From Table 1 and Table 2, we can get:

[0084] The mechanical properties of the pure membrane materials of Comparative Examples 1 to 3 are lower than those of Examples 1 to 2, while the electrochemical properties of the structural energy storage composite materials prepared in Examples 3 to 4 are better than those of the structural energy storage composite materials prepared in Comparative Examples 4 to 5. This shows that the present invention can improve the mechanical properties, battery capacity, and cycle performance of in-situ cured gel structured electrolytes.

[0085] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for preparing an in-situ solidified gel structure electrolyte, characterized in that: The method comprises the following steps: (1) mixing a resin matrix with a pore-forming agent, and then adding a curing agent to mix to obtain a mixed solution, pouring the mixed solution into a closed mold and curing it to obtain a resin film; soaking the resin film and then drying it to obtain a porous resin; (2) 4-styrenesulfonyl (phenylsulfonyl) imide lithium salt, polyethylene glycol methyl ether acrylate, polyethylene glycol dimethacrylate, ethylene carbonate, and azobisisobutyronitrile are mixed to prepare a mixed solution, and the porous resin is immersed in the mixed solution for reaction and solidification, thereby preparing an in-situ solidified gel structure electrolyte.

2. The method for preparing an in-situ solidified gel structure electrolyte according to claim 1, characterized in that: In step (1), the mass ratio of the resin matrix, the pore-forming agent, and the curing agent is 1:2-4:0.1-0.7; The resin matrix is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, special resin, and multifunctional resin; the curing agent is an amine curing agent; and the pore-forming agent is at least one of polyethylene glycol, glucose, ethylene carbonate, and N,N-dimethylformamide.

3. The method for preparing an in-situ solidified gel structure electrolyte according to claim 1, characterized in that: The mass fractions of the raw materials used in step (2) are as follows: the mass ratio of the 4-styrenesulfonyl (phenylsulfonyl) imide lithium salt, the polyethylene glycol methyl ether acrylate, the polyethylene glycol dimethacrylate, ethylene carbonate, and the azobisisobutyronitrile is 0.3-0.5: 0.6-0.8: 0.2-0.4: 1.4-1.6: 2-4×10 -3 .

4. The method for preparing an in-situ solidified gel structure electrolyte according to claim 1, characterized in that: The curing temperature in step (2) is 65-75° C. and the curing time is 10-14 hours.

5. The method for preparing an in-situ solidified gel structure electrolyte according to claim 1, characterized in that: The preparation method of the 4-styrenesulfonyl (phenylsulfonyl) imide lithium salt comprises the following steps: S1. Mixing anhydrous acetonitrile, sodium 4-styrenesulfonate, and N,N-dimethylformamide to obtain a mixture A, adding oxalyl chloride to the mixture A, stirring, and filtering to obtain a filtrate; concentrating the filtrate by rotary evaporation to obtain a concentrated solution, and adding anhydrous acetonitrile to the concentrated solution to obtain an anhydrous acetonitrile solution of 4-styrenesulfonyl chloride; S2, trifluoromethylsulfonamide, 4-dimethylaminopyridine and triethylamine were sequentially added to anhydrous acetonitrile to dissolve to obtain a mixture B, the mixture B was cooled, and an anhydrous acetonitrile solution of 4-styrenesulfonyl chloride was added to obtain a reaction mixture, and then the reaction mixture was kept at a low temperature for a period of time, stirred at room temperature, and finally rotary evaporated to obtain a brown substance; the brown substance was dissolved in dichloromethane, washed and purified, and dichloromethane was added again to dissolve, and rotary evaporated to obtain a viscous brown liquid; S3, K2CO3 and the viscous brown liquid are stirred and reacted, and then vacuum dried to obtain lithium 4-styrenesulfonyl (trifluoromethylsulfonyl) imide; the lithium 4-styrenesulfonyl (trifluoromethylsulfonyl) imide and lithium perchlorate are reacted in CH3CN, and rotary evaporation is performed to obtain lithium 4-styrenesulfonyl (phenylsulfonyl) imide.

6. The method for preparing an in-situ solidified gel structure electrolyte according to claim 5, characterized in that: The mass parts of the raw materials in step S1 are as follows: the usage ratio of the anhydrous acetonitrile, the oxalyl chloride, the N,N-dimethylformamide, and the sodium salt of 4-styrenesulfonate is 110-130 ml: 5-8 ml: 0.1-0.4 g: 10-14 g.

7. The method for preparing an in-situ solidified gel structure electrolyte according to claim 5, characterized in that: The mass fractions of the raw materials in step S2 are as follows: the amount ratio of the trifluoromethylsulfonamide, the 4-dimethylaminopyridine, the triethylamine, the anhydrous acetonitrile, and the anhydrous acetonitrile solution of 4-styrenesulfonyl chloride is 7-9 g: 0.1-0.8 g: 23-25 ml: 90-110 ml: 8-12 ml.

8. The method for preparing an in-situ solidified gel structure electrolyte according to claim 5, characterized in that: In step S3, the usage ratio of lithium 4-styrenesulfonyl (trifluoromethylsulfonyl) imide, the lithium perchlorate, and the CH3CN solution is 3-7 g: 1.5-2.5 g: 100-110 ml.

9. An in-situ solidified gel structure electrolyte, characterized in that: Prepared by the preparation method according to any one of claims 1 to 8.

10. An application of an in-situ cured gel structure electrolyte, characterized in that: The in-situ solidified gel structure electrolyte according to claim 9 is used in the preparation of a battery.

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