High-pressure-resistant polyurethane material for packaging solid-state battery and preparation process of high-pressure-resistant polyurethane material

Abstract

The invention provides a high-pressure-resistant polyurethane material for packaging a solid-state battery and a preparation process of the high-pressure-resistant polyurethane material, and belongs to the field of high polymer materials. The preparation process comprises the following steps: preparing the nanofiller A; preparing a nanofiller B; preparing a coated modified composite filler; preparing a silicon-boron modifier; and synthesizing the polyurethane material. The preparation method comprises the following steps: preparing carbon-coated silicon powder from phenolic resin and silicon powder as raw materials, compounding the carbon-coated silicon powder with boron nitride nanosheets to prepare a nanofiller A, and carrying out a hydrothermal reaction on zinc nitrate hexahydrate and sodium hydroxide as raw materials to prepare zinc oxide nanowires. The method comprises the following steps: preparing a zinc oxide nanowire, mixing with aluminum nitrate and sodium borohydride to prepare a nano-alumina particle and zinc oxide nanowire compounded nano-filler B, and adding a coating modified composite filler prepared by mixing the nano-filler A and the nano-filler B into a polyurethane material to synergistically improve the chemical corrosion resistance and electrical insulation performance of polyurethane.

Description

Technical Field

[0001] The present invention relates to the field of polymer materials, and in particular to a high-pressure resistant polyurethane material for solid-state battery packaging and a preparation process thereof. Background Art

[0002] Solid-state batteries are a new energy storage technology with great potential. Compared with traditional liquid batteries, solid-state batteries have significant advantages such as higher energy density, better safety and longer service life. Therefore, they are widely considered to be one of the key technologies for future electric vehicles and large-scale energy storage systems. However, in the actual use of batteries, packaging materials need to withstand complex and changeable chemical environments and high pressure conditions. On the one hand, the electrolytes and electrode materials inside the battery may react chemically with the packaging materials, resulting in performance degradation of the packaging materials, such as swelling, corrosion, rupture and other problems. This will not only affect the packaging effect of the battery, but may also cause serious safety hazards such as internal short circuits and electrolyte leakage in the battery, greatly reducing the reliability and service life of the battery. On the other hand, solid-state batteries will produce certain gases during the charging and discharging process, resulting in increased internal pressure in the battery. The packaging materials are required to have good high-pressure resistance to prevent the battery shell from being deformed or even ruptured due to excessive pressure, thereby ensuring the structural integrity and safety of the battery.

[0003] At present, commonly used battery packaging materials include metal materials, ceramic materials and polymer materials. Although metal materials have high strength and good conductivity, they have poor corrosion resistance and are easily corroded by chemical substances inside the battery. In addition, they are heavy, which is not conducive to improving the energy density and lightweight design of the battery. Ceramic materials have excellent high temperature resistance and chemical stability, but they are brittle and have poor processing performance. It is difficult to meet the packaging requirements of batteries with complex shapes, and the cost is high. Polymer materials have become one of the research hotspots of battery packaging materials due to their advantages such as light weight, convenient molding and processing, and relatively low cost. Polyurethane materials, as an important polymer material, have good flexibility, wear resistance, adhesion and mechanical properties, and have been widely used in many fields. However, ordinary polyurethane materials have shortcomings in chemical corrosion resistance and high voltage resistance, and are difficult to be directly applied to the packaging of solid-state batteries.

[0004] Therefore, it is necessary to develop a high-pressure resistant polyurethane material for solid-state battery packaging with excellent chemical corrosion resistance and a preparation process thereof to extend its service life. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide a high-pressure resistant polyurethane material for solid-state battery packaging and a preparation process thereof.

[0006] A preparation process of a high-voltage resistant polyurethane material for solid-state battery packaging, comprising the following steps: S1: Preparation of Nanofiller A Silicon powder is dispersed in a phenolic resin solution, centrifuged and heated to obtain carbon-coated silicon powder, which is then dispersed in anhydrous ethanol together with boron nitride nanosheets, deionized water is added, stirred and mixed, centrifuged, vacuum dried and heat treated to obtain nanofiller A; S2: Preparation of Nanofiller B Dissolving zinc nitrate hexahydrate and sodium hydroxide separately, mixing them and performing a hydrothermal reaction to prepare zinc oxide nanowires, then dissolving aluminum nitrate and sodium borohydride and mixing them, adding the zinc oxide nanowires and reacting them to obtain nanofiller B; S3: Preparation of coated modified composite fillers The nanofiller A and the nanofiller B are dispersed in an ethanol solution, and then a titanium sulfate solution and a chitosan quaternary ammonium salt are added to react to obtain a coated modified composite filler; S4: Preparation of silicon-boron modifier Vinyl triethoxysilane, amino triethoxysilane, phenyl diethoxysilane and HCl aqueous solution are mixed and heated to react, and then a boric acid solution is added to continue the reaction to obtain a silicon boron modifier; S5: Synthetic polyurethane material Add polyol, isocyanate and dibutyltin dilaurate into a reactor, heat at 70-80°C for 2-4h, then add chain extender, the above-mentioned coated modified composite filler, the above-mentioned silicon boron modifier and tetrabutyl titanate, stir at 20-30°C for 1-2h, and obtain a polyurethane material through vacuum degassing and curing.

[0007] Furthermore, S1 specifically includes the following steps: S1.1: Add phenolic resin to anhydrous ethanol at a solid-liquid ratio of 1 g: (20-30) mL, heat and stir at 40-50 °C for 1-2 h to fully dissolve, and obtain a phenolic resin solution; S1.2: Disperse silicon powder in the above phenolic resin solution at a solid-liquid ratio of 1 g: (50-60) mL, centrifuge at a rate of 5000-6000 r / min for 20-30 min, separate solid particles, and then heat at 600-800°C for 3-4 h under a nitrogen atmosphere to obtain carbon-coated silicon powder; S1.3: Add the boron nitride nanosheets and the carbon-coated silicon powder into anhydrous ethanol at a solid-liquid ratio of 1 g: (3-5) g: (50-60) mL, perform ultrasonic treatment for 10-20 min, and then heat and stir at 40-50 ° C for 2-3 h to obtain a mixed precursor solution; S1.4: Add the above mixed precursor solution into deionized water in a volume ratio of 1: (1.5-2.5), continue stirring for 1-2 hours, centrifuge and vacuum dry at 60-80℃ for 8-10 hours, heat grind at 700-800℃ for 2-3 hours, and then heat treat at 1500-1600℃ for 1-2 hours to obtain nanofiller A.

[0008] Furthermore, S2 specifically includes the following steps: S2.1: Dissolve zinc nitrate hexahydrate and sodium hydroxide in deionized water at a solid-liquid ratio of 1 g: (40-50) mL to obtain zinc nitrate solution and sodium hydroxide solution; S2.2: Stir and mix equal volumes of the zinc nitrate solution and the sodium hydroxide solution, transfer them to a hydrothermal reactor, heat at 175-185° C. for 8-10 hours, and obtain zinc oxide nanowires after washing and drying; S2.3: Dissolve aluminum nitrate and sodium borohydride in deionized water at a solid-liquid ratio of 1g:(0.02-0.03)g:(80-90)mL, stir and mix thoroughly, then add the above zinc oxide nanowires at a solid-liquid ratio of 1g:(140-150)mL, stir and react for 2-3h, and obtain nanofiller B after filtering, washing and drying.

[0009] Furthermore, S3 specifically includes the following steps: S3.1: Add titanium sulfate powder to 1wt% acetic acid solution at a solid-liquid ratio of 1g:(70-80)mL, stir thoroughly to dissolve, and obtain titanium sulfate solution; S3.2: Add the nanofiller A prepared in step S1.4 and the nanofiller B prepared in step S2.3 to a 50% ethanol solution at a solid-liquid ratio of 1 g: (1-3) g: (100-120) mL, and ultrasonically disperse for 1-2 h to obtain a binary suspension; S3.3: Add the titanium sulfate solution to the binary suspension, disperse by ultrasonic for 10-20 min, and then heat and stir at 75-85°C for 1-2 h to obtain a ternary suspension; S3.4: Add chitosan quaternary ammonium salt to the above ternary suspension, continue stirring for 4-5 hours to react, and obtain a coated modified composite filler through centrifugal separation, washing, drying and grinding.

[0010] Furthermore, S4 specifically includes the following steps: S4.1: Add boric acid to anhydrous ethanol at a solid-liquid ratio of 1 g: (30-40) mL, stir and mix thoroughly to obtain a boric acid solution; S4.2: Vinyl triethoxysilane, amino triethoxysilane and phenyl diethoxysilane are stirred at a rate of 200-300 r / min and heated to 70-80°C, and then an aqueous solution of HCl is added while stirring, and the mixture is kept warm for 1-2 hours to obtain a precursor mixture; S4.3: Add the above boric acid solution to the above precursor mixture, continue the reaction for 3-4 hours, and remove impurities by vacuum distillation to obtain a silicon-boron modifier.

[0011] Furthermore, the mass ratio of titanium sulfate to the total amount of nanofiller A and nanofiller B is (1.5-2.5):1, and the mass ratio of chitosan quaternary ammonium salt to the total amount of nanofiller A and nanofiller B is (3-4):1.

[0012] Furthermore, the volume ratio of the HCl aqueous solution to the total amount of vinyltriethoxysilane, aminotriethoxysilane and phenyldiethoxysilane is 1:(12-14), and the HCl aqueous solution is a (2-3) mol / L hydrochloric acid solution.

[0013] Furthermore, the polyol is one or more of polysiloxane polyol, polyether polyol or polyester polyol, the isocyanate is one or more of diphenylmethane diisocyanate and hexamethylene diisocyanate, and the chain extender is one or more of ethylene glycol and diethylene glycol.

[0014] Furthermore, the raw material components of the polyurethane material include, by mass: 40-50 parts of polyol, 35-45 parts of isocyanate, 0.2-0.4 parts of dibutyltin dilaurate, 2-4 parts of chain extender, 13-15 parts of coated modified composite filler, 15-20 parts of silicon boron modifier and 0.8-1.2 parts of tetrabutyl titanate.

[0015] Furthermore, a high-voltage resistant polyurethane material for solid-state battery encapsulation is prepared by the preparation process of a high-voltage resistant polyurethane material for solid-state battery encapsulation described in any of the above items.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: 1. The present invention prepares carbon-coated silicon powder by first using phenolic resin and silicon powder as raw materials, and then composites it with boron nitride nanosheets to prepare nanofiller A, and then uses zinc nitrate hexahydrate and sodium hydroxide as raw materials to carry out hydrothermal reaction to prepare zinc oxide nanowires, and mixes them with aluminum nitrate and sodium borohydride to prepare nanofiller B composited with nano aluminum oxide particles and zinc oxide nanowires. After the coated modified composite filler prepared by mixing nanofiller A and nanofiller B is added to a polyurethane material, on the one hand, nanofiller A and nanofiller B jointly construct a multi-level physical barrier to reduce the contact opportunity between corrosive substances and polyurethane molecules, thereby achieving the effect of synergistically improving the chemical corrosion resistance of polyurethane. On the other hand, since nanofiller A and nanofiller B themselves have good insulation, in the polyurethane matrix, the migration path of carriers therein can be tortuous, the probability of carrier scattering is increased, thereby reducing the mobility of carriers, achieving the purpose of synergistically improving the electrical insulation of polyurethane, and further improving its high voltage resistance.

[0017] 2. The present invention disperses the nanofiller A and the nanofiller B in an ethanol solution, then adds an aqueous solution of titanium sulfate and chitosan quaternary ammonium salt to react, and uses titanium sulfate as a cross-linking agent to coat the chitosan quaternary ammonium salt on the surface of the nanofiller A and the nanofiller B to form a steric hindrance layer, thereby preventing direct contact and interaction between the nanofillers, thereby reducing their agglomeration in the polyurethane, and maintaining a good dispersion state in the polyurethane, thereby achieving the effect of improving the dispersibility of the nanofiller A and the nanofiller B, and further improving the chemical corrosion resistance and electrical insulation performance of the prepared polyurethane.

[0018] 3. The present invention prepares a silicon-boron modifier by first using vinyl triethoxysilane, amino triethoxysilane, phenyl diethoxysilane and boric acid as raw materials, wherein boron is doped in the form of BO-Si in the organic silicon molecule, and then reacts the silicon-boron modifier with a polyurethane prepolymer under the catalysis of tetrabutyl titanate to modify the polyurethane material. Due to the high bond energy of BO-Si in the silicon-boron modifier, an inorganic heat-insulating layer containing Si-O-Si and BO-Si can be formed on the surface of the polyurethane material at high temperature, thereby protecting the polyurethane material matrix from being destroyed under thermal shock, thereby effectively improving the thermal stability of the polyurethane material. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable those skilled in the relevant art to make and use the present disclosure.

[0020] Figure 1 This is a process flow chart for preparing the high-pressure resistant polyurethane material for solid-state battery packaging used in an embodiment of the present invention.

[0021] Figure 2 This is a SEM image of filler A prepared in Example 1 of the present invention.

[0022] Figure 3 This is the SEM image of filler B prepared in Example 1 of the present invention.

[0023] Figure 4 This is the infrared spectrum of the silicon-boron modifier prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0024] The following is a detailed description of a high-pressure resistant polyurethane material for solid-state battery packaging and its preparation process provided by the present invention in conjunction with the accompanying drawings and specific embodiments. Example

[0025] A preparation process of a high-voltage resistant polyurethane material for solid-state battery packaging, such as Figure 1 As shown, the following steps are included: S1: Preparation of Nanofiller A S1.1: Add phenolic resin into anhydrous ethanol at a solid-liquid ratio of 1g:20mL, heat and stir at 40℃ for 1h to fully dissolve, and obtain a phenolic resin solution; S1.2: Disperse silicon powder in the above phenolic resin solution at a solid-liquid ratio of 1g:50mL, centrifuge at a rate of 5000r / min for 20min, separate solid particles, and then heat at 600℃ for 3h under nitrogen atmosphere to obtain carbon-coated silicon powder; S1.3: Add the boron nitride nanosheets and the carbon-coated silicon powder into anhydrous ethanol at a solid-liquid ratio of 1g:3g:50mL, ultrasonically treat for 10min, and then heat and stir at 40°C for 2h to obtain a mixed precursor solution; S1.4: The mixed precursor solution was added into deionized water at a volume ratio of 1:1.5, and the mixture was stirred for 1 h. After centrifugal separation and vacuum drying at 60°C for 8 h, the mixture was heated and ground at 700°C for 2 h, and then heat treated at 1500°C for 1 h to obtain nanofiller A. The SEM image of the nanofiller A is shown in FIG. Figure 2 As shown; S2: Preparation of Nanofiller B S2.1: Dissolve zinc nitrate hexahydrate and sodium hydroxide in deionized water at a solid-liquid ratio of 1 g:40 mL to obtain a zinc nitrate solution and a sodium hydroxide solution; S2.2: Stir and mix equal volumes of the zinc nitrate solution and the sodium hydroxide solution, transfer them to a hydrothermal reactor, heat and react at 175° C. for 8 h, and obtain zinc oxide nanowires after washing and drying; S2.3: Aluminum nitrate and sodium borohydride were dissolved in deionized water at a solid-liquid ratio of 1g:0.02g:80mL, and the mixture was fully stirred. Then, the zinc oxide nanowires were added at a solid-liquid ratio of 1g:140mL, and the mixture was stirred for 2h. After filtering, washing and drying, nanofiller B was obtained, and its SEM image was shown as follows: Figure 3 As shown; S3: Preparation of coated modified composite fillers S3.1: Add titanium sulfate powder to 1 wt% acetic acid solution at a solid-liquid ratio of 1 g:70 mL, stir thoroughly to dissolve, and obtain a titanium sulfate solution; S3.2: Add the nanofiller A prepared in step S1.4 and the nanofiller B prepared in step S2.3 to 50% ethanol solution at a solid-liquid ratio of 1g:1g:100mL, and ultrasonically disperse for 1h to obtain a binary suspension; S3.3: adding the titanium sulfate solution to the binary suspension, ultrasonically dispersing for 10 minutes, and then heating and stirring at 75°C for 1 hour to obtain a ternary suspension, wherein the mass ratio of titanium sulfate to the total amount of nanofiller A and nanofiller B is 1.5:1; S3.4: chitosan quaternary ammonium salt is added to the above ternary suspension, and stirring is continued for 4 hours to react, and a coated modified composite filler is obtained by centrifugation, washing, drying and grinding, wherein the mass ratio of chitosan quaternary ammonium salt to the total amount of nanofiller A and nanofiller B is 3:1; S4: Preparation of silicon-boron modifier S4.1: Add boric acid to anhydrous ethanol at a solid-liquid ratio of 1 g:30 mL, and stir well to obtain a boric acid solution; S4.2: Vinyl triethoxysilane, amino triethoxysilane and phenyl diethoxysilane are stirred at a rate of 200 r / min and heated to 70°C in a mass ratio of 1:1:1, and then an HCl aqueous solution is added while stirring, and the mixture is kept warm for 1 hour to obtain a precursor mixture, wherein the volume ratio of the HCl aqueous solution to the total amount of vinyl triethoxysilane, amino triethoxysilane and phenyl diethoxysilane is 1:12, and the HCl aqueous solution is a 2 mol / L hydrochloric acid solution; S4.3: adding the boric acid solution to the precursor mixture, continuing the reaction for 3 hours, and removing impurities by vacuum distillation to obtain a silicon-boron modifier; S5: Synthetic polyurethane material 40 parts by mass of polysiloxane polyol, 35 parts by mass of diphenylmethane diisocyanate and 0.2 parts by mass of dibutyltin dilaurate were added into a reactor and heated at 70°C for 2 hours. Then, 2 parts by mass of ethylene glycol, 13 parts by mass of the above-mentioned coated modified composite filler, 15 parts by mass of the above-mentioned silicon boron modifier and 0.8 parts by mass of tetrabutyl titanate were added, stirred at 20°C for 1 hour, and vacuum degassed and cured to obtain a polyurethane material. Example

[0026] A preparation process of a high-voltage resistant polyurethane material for solid-state battery packaging, such as Figure 1 As shown, the following steps are included: S1: Preparation of Nanofiller A S1.1: Add phenolic resin to anhydrous ethanol at a solid-liquid ratio of 1g:25mL, heat and stir at 45°C for 1.5h to fully dissolve, and obtain a phenolic resin solution; S1.2: Disperse silicon powder in the above phenolic resin solution at a solid-liquid ratio of 1g:55mL, centrifuge at a rate of 5500r / min for 25min, separate solid particles, and then heat at 700℃ for 3.5h under nitrogen atmosphere to obtain carbon-coated silicon powder; S1.3: Add the boron nitride nanosheets and the carbon-coated silicon powder into anhydrous ethanol at a solid-liquid ratio of 1g:4g:55mL, ultrasonically treat for 15min, and then heat and stir at 45°C for 2.5h to obtain a mixed precursor solution; S1.4: The mixed precursor solution was added to deionized water at a volume ratio of 1:2, and the mixture was stirred for 1.5 h. After centrifugal separation and vacuum drying at 70°C for 9 h, the mixture was heated and ground at 750°C for 2.5 h, and then heat-treated at 1550°C for 1.5 h to obtain nanofiller A. S2: Preparation of Nanofiller B S2.1: Dissolve zinc nitrate hexahydrate and sodium hydroxide in deionized water at a solid-liquid ratio of 1 g:45 mL to obtain a zinc nitrate solution and a sodium hydroxide solution; S2.2: Stir and mix equal volumes of the zinc nitrate solution and the sodium hydroxide solution, transfer them to a hydrothermal reactor, heat them at 180° C. for 9 h, and obtain zinc oxide nanowires after washing and drying; S2.3: Aluminum nitrate and sodium borohydride were dissolved in deionized water at a solid-liquid ratio of 1g:0.025g:85mL, and the mixture was fully stirred and mixed. Then, the zinc oxide nanowires were added at a solid-liquid ratio of 1g:145mL, and the mixture was stirred and reacted for 2.5h. After filtering, washing and drying, the nanofiller B was obtained. S3: Preparation of coated modified composite fillers S3.1: Add titanium sulfate powder to 1wt% acetic acid solution at a solid-liquid ratio of 1g:75mL, stir thoroughly to dissolve, and obtain titanium sulfate solution; S3.2: Add the nanofiller A prepared in step S1.4 and the nanofiller B prepared in step S2.3 to 50% ethanol solution at a solid-liquid ratio of 1g:2g:110mL, and ultrasonically disperse for 1.5h to obtain a binary suspension; S3.3: adding the titanium sulfate solution to the binary suspension, ultrasonically dispersing for 15 minutes, and then heating and stirring at 80°C for 1.5 hours to obtain a ternary suspension, wherein the mass ratio of titanium sulfate to the total amount of nanofiller A and nanofiller B is 2:1; S3.4: chitosan quaternary ammonium salt is added to the above ternary suspension, and stirring is continued for 4.5 hours to react, and a coated modified composite filler is obtained by centrifugal separation, washing, drying and grinding, wherein the mass ratio of chitosan quaternary ammonium salt to the total amount of nanofiller A and nanofiller B is 3.5:1; S4: Preparation of silicon-boron modifier S4.1: Add boric acid to anhydrous ethanol at a solid-liquid ratio of 1 g:35 mL, and stir thoroughly to obtain a boric acid solution; S4.2: Vinyl triethoxysilane, amino triethoxysilane and phenyl diethoxysilane are stirred at a rate of 250 r / min and heated to 75°C in a mass ratio of 1:2:2, and then an HCl aqueous solution is added while stirring, and the mixture is kept warm for 1.5 hours to obtain a precursor mixture, wherein the volume ratio of the HCl aqueous solution to the total amount of vinyl triethoxysilane, amino triethoxysilane and phenyl diethoxysilane is 1:13, and the HCl aqueous solution is a 2.5 mol / L hydrochloric acid solution; S4.3: adding the boric acid solution to the precursor mixture, continuing the reaction for 3.5 hours, and removing impurities by vacuum distillation to obtain a silicon-boron modifier; S5: Synthetic polyurethane material 45 parts by mass of polyether polyol, 40 parts by mass of hexamethylene diisocyanate and 0.3 parts by mass of dibutyltin dilaurate were added into a reactor and heated at 75°C for 3 hours. Then, 3 parts by mass of diethylene glycol, 14 parts by mass of the above-mentioned coated modified composite filler, 17 parts by mass of the above-mentioned silicon boron modifier and 1 part by mass of tetrabutyl titanate were added, stirred at 25°C for 1.5 hours, and vacuum degassed and cured to obtain a polyurethane material. Example

[0027] A preparation process of a high-voltage resistant polyurethane material for solid-state battery packaging, such as Figure 1 As shown, the following steps are included: S1: Preparation of Nanofiller A S1.1: Add phenolic resin to anhydrous ethanol at a solid-liquid ratio of 1g:30mL, heat and stir at 40-50℃ for 2h to fully dissolve, and obtain a phenolic resin solution; S1.2: Disperse silicon powder in the above phenolic resin solution at a solid-liquid ratio of 1g:60mL, centrifuge at a rate of 6000r / min for 30min, separate solid particles, and then heat at 800℃ for 4h under nitrogen atmosphere to obtain carbon-coated silicon powder; S1.3: Add the boron nitride nanosheets and the carbon-coated silicon powder into anhydrous ethanol at a solid-liquid ratio of 1g:5g:60mL, ultrasonically treat for 20min, and then heat and stir at 50°C for 3h to obtain a mixed precursor solution; S1.4: The mixed precursor solution was added to deionized water at a volume ratio of 1:2.5, and the mixture was stirred for 2 h. After centrifugal separation and vacuum drying at 80°C for 10 h, the mixture was heated and ground at 800°C for 3 h, and then heat-treated at 1600°C for 2 h to obtain nanofiller A. S2: Preparation of Nanofiller B S2.1: Dissolve zinc nitrate hexahydrate and sodium hydroxide in deionized water at a solid-liquid ratio of 1 g:50 mL to obtain a zinc nitrate solution and a sodium hydroxide solution; S2.2: Stir and mix equal volumes of the zinc nitrate solution and the sodium hydroxide solution, transfer them to a hydrothermal reactor, heat them at 185° C. for 10 h, and obtain zinc oxide nanowires after washing and drying; S2.3: Aluminum nitrate and sodium borohydride were dissolved in deionized water at a solid-liquid ratio of 1g:0.03g:90mL, and the mixture was fully stirred and mixed. Then, the zinc oxide nanowires were added at a solid-liquid ratio of 1g:150mL, and the mixture was stirred and reacted for 3h. After filtering, washing and drying, the nanofiller B was obtained. S3: Preparation of coated modified composite fillers S3.1: Add titanium sulfate powder to 1wt% acetic acid solution at a solid-liquid ratio of 1g:80mL, stir thoroughly to dissolve, and obtain titanium sulfate solution; S3.2: Add the nanofiller A prepared in step S1.4 and the nanofiller B prepared in step S2.3 to 50% ethanol solution at a solid-liquid ratio of 1g:3g:120mL, and ultrasonically disperse for 2h to obtain a binary suspension; S3.3: adding the titanium sulfate solution to the binary suspension, ultrasonically dispersing for 20 minutes, and then heating and stirring at 85°C for 2 hours to obtain a ternary suspension, wherein the mass ratio of titanium sulfate to the total amount of nanofiller A and nanofiller B is 2.5:1; S3.4: chitosan quaternary ammonium salt is added to the above ternary suspension, and stirring is continued for 5 hours to react, and a coated modified composite filler is obtained by centrifugation, washing, drying and grinding, wherein the mass ratio of chitosan quaternary ammonium salt to the total amount of nanofiller A and nanofiller B is 4:1; S4: Preparation of silicon-boron modifier S4.1: Add boric acid to anhydrous ethanol at a solid-liquid ratio of 1 g:40 mL, stir and mix thoroughly to obtain a boric acid solution; S4.2: Vinyl triethoxysilane, amino triethoxysilane and phenyl diethoxysilane are stirred at a rate of 300 r / min and heated to 80°C in a mass ratio of 1:3:3, and then an HCl aqueous solution is added while stirring, and the mixture is kept warm for 2 hours to obtain a precursor mixture, wherein the volume ratio of the HCl aqueous solution to the total amount of vinyl triethoxysilane, amino triethoxysilane and phenyl diethoxysilane is 1:14, and the HCl aqueous solution is a 3 mol / L hydrochloric acid solution; S4.3: adding the boric acid solution to the precursor mixture, continuing the reaction for 4 hours, and removing impurities by vacuum distillation to obtain a silicon-boron modifier; S5: Synthetic polyurethane material 50 parts by mass of polysiloxane polyol, 45 parts by mass of hexamethylene diisocyanate and 0.4 parts by mass of dibutyltin dilaurate were added into a reactor and heated at 80°C for 4 hours. Then, 4 parts by mass of diethylene glycol, 15 parts by mass of the above-mentioned coated modified composite filler, 20 parts by mass of the above-mentioned silicon boron modifier and 1.2 parts by mass of tetrabutyl titanate were added, stirred at 30°C for 2 hours, and vacuum degassed and cured to obtain a polyurethane material.

[0028] Comparative Example 1 The difference between this comparative example 1 and example 1 is that the nanofiller A in step S3.2 is replaced by an equal amount of nanofiller B.

[0029] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the nanofiller B in step S3.2 is replaced by an equal amount of nanofiller A.

[0030] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that step S3 is removed, and nanofiller A and nanofiller B are directly added into the reactor at a mass ratio of 1:1 to prepare the polyurethane material.

[0031] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that the silicon-boron modifier in step S5 is removed.

[0032] Test Case Test 1: The chemical corrosion resistance of the polyurethane material obtained in Example 1-3, i.e., Comparative Example 1-3, was tested. The polyurethane material was immersed in a 5% by mass sodium hydroxide solution at 28° C. for 48 hours, and the corrosion of the polyurethane material was analyzed. The results are shown in Table 1.

[0033] Test 2: The surface resistivity and volume resistivity of the polyurethane materials prepared in Examples 1-3 and Comparative Examples 1-3 were tested. The results are shown in Table 1.

[0034] Table 1: Comparison of polyurethane material corrosion and insulation test results Corrosion Surface resistivity / Ω Volume resistivity / Ω·cm Example 1 No abnormality <![CDATA[5.68×10 15 ]]> <![CDATA[5.56×10 15 ]]> Example 2 No abnormality <![CDATA[5.72×10 15 ]]> <![CDATA[5.63×10 15 ]]> Example 3 No abnormality <![CDATA[5.71×10 15 ]]> <![CDATA[5.49×10 15 ]]> Comparative Example 1 Spots appear <![CDATA[4.85×10 14 ]]> <![CDATA[3.89×10 14 ]]> Comparative Example 2 Spots appear <![CDATA[4.21×10 14 ]]> <![CDATA[3.65×10 14 ]]> Comparative Example 3 Discoloration <![CDATA[7.82×10 13 ]]> <![CDATA[7.96×10 13 ]]> As can be seen from Table 1, the polyurethane materials prepared by using single nanofiller B and single nanofiller A in Comparative Examples 1 and 2 showed spots after being immersed in sodium hydroxide solution for 48 hours, while the polyurethane materials prepared by using nanofiller A and nanofiller B in Examples 1-3 showed no abnormality, indicating that nanofiller A and nanofiller B have the effect of synergistically improving the chemical corrosion resistance of the polyurethane material. In addition, the surface resistivity and volume resistivity of the polyurethane materials prepared in Comparative Examples 1 and 2 are both less than those in Examples 1-3, which shows that nanofiller A and nanofiller B also have the effect of synergistically improving the insulation performance of the polyurethane material. However, after being corroded by sodium hydroxide solution for 48 hours, the polyurethane material prepared in Comparative Example 3 showed spots and discoloration, and the surface resistivity and volume resistivity were also lower than those of Examples 1-3. It can be seen that by first dispersing nanofiller A and nanofiller B in an ethanol solution, then adding an aqueous solution of titanium sulfate and chitosan quaternary ammonium salt to react, and using titanium sulfate as a cross-linking agent to coat the chitosan quaternary ammonium salt on the surface of nanofiller A and nanofiller B, the dispersibility of nanofiller A and nanofiller B can be improved, and the chemical corrosion resistance and electrical insulation properties of the prepared polyurethane can be further improved.

[0035] Test 3: The silicon-boron modifier prepared in Example 1 was characterized by infrared spectroscopy. Figure 4 As shown; a thermogravimetric analyzer was used to test the temperature at which the mass loss of the polyurethane materials obtained in Examples 1-3 and Comparative Example 4 was 5%. The test conditions were: the mass of the polyurethane material was 10 mg and it was heated to 800°C in an air atmosphere. The results are shown in Table 2.

[0036] Table 2: Comparison of thermal stability test results of polyurethane materials Example 1 Example 2 Example 3 Comparative Example 4 Temperature at which mass loss is 5% (°C) 302.87 304.16 305.21 268.42 like Figure 4 As shown, the silicon-boron modifier is at 1343 cm -1 The absorption peaks at 1262 cm -1 The absorption peaks at 695 cm are the stretching vibration peaks of Si-C. -1 The absorption peak at is the BO-Si in-plane shear vibration peak. In summary, boron is doped into the organosilicon molecule in the form of BO-Si. In addition, it can be seen from Table 2 that when the silicon boron modifier is not used for modification in Comparative Example 4, the temperature at which the mass loss of the obtained polyurethane material is 5% is about 268.42°C, which is lower than that of Examples 1-3. It can be seen that by first preparing the silicon boron modifier with vinyl triethoxysilane, amino triethoxysilane, phenyl diethoxysilane and boric acid as raw materials, and then reacting the silicon boron modifier with the polyurethane prepolymer under the catalysis of tetrabutyl titanate to modify the polyurethane material, the thermal stability of the polyurethane material can be improved.

[0037] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A preparation process of a high-voltage resistant polyurethane material for solid-state battery packaging, characterized in that: The steps include: S1: Preparation of Nanofiller A Silicon powder is dispersed in a phenolic resin solution, centrifuged and heated to obtain carbon-coated silicon powder, which is then dispersed in anhydrous ethanol together with boron nitride nanosheets, deionized water is added, stirred and mixed, centrifuged, vacuum dried and heat treated to obtain nanofiller A; S2: Preparation of Nanofiller B Dissolving zinc nitrate hexahydrate and sodium hydroxide separately, mixing them and performing a hydrothermal reaction to prepare zinc oxide nanowires, then dissolving aluminum nitrate and sodium borohydride and mixing them, adding the zinc oxide nanowires and reacting them to obtain nanofiller B; S3: Preparation of coated modified composite fillers The nanofiller A and the nanofiller B are dispersed in an ethanol solution, and then a titanium sulfate solution and a chitosan quaternary ammonium salt are added to react to obtain a coated modified composite filler; S4: Preparation of silicon-boron modifier Vinyl triethoxysilane, amino triethoxysilane, phenyl diethoxysilane and HCl aqueous solution are mixed and heated to react, and then a boric acid solution is added to continue the reaction to obtain a silicon boron modifier; S5: Synthetic polyurethane material Add polyol, isocyanate and dibutyltin dilaurate into a reactor, heat at 70-80°C for 2-4h, then add chain extender, the above-mentioned coated modified composite filler, the above-mentioned silicon boron modifier and tetrabutyl titanate, stir at 20-30°C for 1-2h, and obtain a polyurethane material through vacuum degassing and curing.

2. The process for preparing a high-pressure resistant polyurethane material for solid-state battery packaging according to claim 1, characterized in that: S1 includes the following steps: S1.1: Add phenolic resin to anhydrous ethanol at a solid-liquid ratio of 1 g: (20-30) mL, heat and stir at 40-50 °C for 1-2 h to fully dissolve, and obtain a phenolic resin solution; S1.2: Disperse silicon powder in the above phenolic resin solution at a solid-liquid ratio of 1 g: (50-60) mL, centrifuge at a rate of 5000-6000 r / min for 20-30 min, separate solid particles, and then heat at 600-800°C for 3-4 h under a nitrogen atmosphere to obtain carbon-coated silicon powder; S1.3: Add the boron nitride nanosheets and the carbon-coated silicon powder into anhydrous ethanol at a solid-liquid ratio of 1 g: (3-5) g: (50-60) mL, perform ultrasonic treatment for 10-20 min, and then heat and stir at 40-50 ° C for 2-3 h to obtain a mixed precursor solution; S1.4: Add the above mixed precursor solution into deionized water in a volume ratio of 1: (1.5-2.5), continue stirring for 1-2 hours, centrifuge and vacuum dry at 60-80℃ for 8-10 hours, heat grind at 700-800℃ for 2-3 hours, and then heat treat at 1500-1600℃ for 1-2 hours to obtain nanofiller A.

3. The process for preparing a high-pressure resistant polyurethane material for solid-state battery packaging according to claim 2, characterized in that: S2 includes the following steps: S2.1: Dissolve zinc nitrate hexahydrate and sodium hydroxide in deionized water at a solid-liquid ratio of 1 g: (40-50) mL to obtain a zinc nitrate solution and a sodium hydroxide solution; S2.2: Stir and mix equal volumes of the zinc nitrate solution and the sodium hydroxide solution, transfer them to a hydrothermal reactor, heat at 175-185° C. for 8-10 hours, and obtain zinc oxide nanowires after washing and drying; S2.3: Dissolve aluminum nitrate and sodium borohydride in deionized water at a solid-liquid ratio of 1g:(0.02-0.03)g:(80-90)mL, stir and mix thoroughly, then add the above zinc oxide nanowires at a solid-liquid ratio of 1g:(140-150)mL, stir and react for 2-3h, and obtain nanofiller B after filtering, washing and drying.

4. The process for preparing a high-pressure resistant polyurethane material for solid-state battery packaging according to claim 3, characterized in that: S3 includes the following steps: S3.1: Add titanium sulfate powder to 1wt% acetic acid solution at a solid-liquid ratio of 1g:(70-80)mL, stir thoroughly to dissolve, and obtain titanium sulfate solution; S3.2: Add the nanofiller A prepared in step S1.4 and the nanofiller B prepared in step S2.3 to a 50% ethanol solution at a solid-liquid ratio of 1 g: (1-3) g: (100-120) mL, and ultrasonically disperse for 1-2 h to obtain a binary suspension; S3.3: Add the titanium sulfate solution to the binary suspension, disperse by ultrasonic for 10-20 min, and then heat and stir at 75-85°C for 1-2 h to obtain a ternary suspension; S3.4: Add chitosan quaternary ammonium salt to the above ternary suspension, continue stirring for 4-5 hours to react, and obtain a coated modified composite filler through centrifugal separation, washing, drying and grinding.

5. The process for preparing a high-pressure resistant polyurethane material for solid-state battery packaging according to claim 4, characterized in that: S4 specifically includes the following steps: S4.1: Add boric acid to anhydrous ethanol at a solid-liquid ratio of 1 g: (30-40) mL, stir and mix thoroughly to obtain a boric acid solution; S4.2: Vinyl triethoxysilane, amino triethoxysilane and phenyl diethoxysilane are stirred at a rate of 200-300 r / min and heated to 70-80°C, and then an aqueous solution of HCl is added while stirring, and the mixture is kept warm for 1-2 hours to obtain a precursor mixture; S4.3: Add the above boric acid solution to the above precursor mixture, continue the reaction for 3-4 hours, and remove impurities by vacuum distillation to obtain a silicon-boron modifier.

6. The process for preparing a high-pressure resistant polyurethane material for solid-state battery packaging according to claim 4, characterized in that: The mass ratio of titanium sulfate to the total amount of nanofiller A and nanofiller B is (1.5-2.5):1, and the mass ratio of chitosan quaternary ammonium salt to the total amount of nanofiller A and nanofiller B is (3-4):

1.

7. The process for preparing a high-pressure resistant polyurethane material for solid-state battery packaging according to claim 5, characterized in that: The volume ratio of the HCl aqueous solution to the total amount of vinyltriethoxysilane, aminotriethoxysilane and phenyldiethoxysilane is 1:(12-14), and the HCl aqueous solution is a (2-3) mol / L hydrochloric acid solution.

8. The process for preparing a high-pressure resistant polyurethane material for solid-state battery packaging according to claim 1, characterized in that: The polyol is one or more of polysiloxane polyol, polyether polyol or polyester polyol, the isocyanate is one or more of diphenylmethane diisocyanate and hexamethylene diisocyanate, and the chain extender is one or more of ethylene glycol and diethylene glycol.

9. The process for preparing a high-pressure resistant polyurethane material for solid-state battery packaging according to claim 1, characterized in that: The raw material components of the polyurethane material include, by mass: 40-50 parts of polyol, 35-45 parts of isocyanate, 0.2-0.4 parts of dibutyltin dilaurate, 2-4 parts of chain extender, 13-15 parts of coated modified composite filler, 15-20 parts of silicon boron modifier and 0.8-1.2 parts of tetrabutyl titanate.

10. A high-voltage resistant polyurethane material for solid-state battery packaging, characterized in that: It is prepared by the preparation process of a high-pressure resistant polyurethane material for solid-state battery packaging as described in any one of claims 1 to 9.

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