Multi-layer composite phase change heat resisting sheet, preparation method and application of multi-layer composite phase change heat resisting sheet in battery thermal runaway protection
By combining phase change materials with thermal insulation materials through the preparation method of multilayer composite phase change thermal insulation sheets, the problems of poor heat transfer and leakage in battery thermal management are solved, achieving rapid heat transfer and thermal insulation effect, and improving battery safety.
Patent Information
- Application Number
- CN202511116497.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-11
- Publication Date
- 2025-11-21
AI Technical Summary
Existing phase change materials suffer from poor heat transfer and low thermal conductivity in battery thermal management, which affects energy storage and release and makes them prone to leakage.
A method for preparing multilayer composite phase change thermal insulation sheets is employed, combining phase change materials with thermal insulation materials. The phase change materials absorb and rapidly transfer heat when the battery temperature rises, while the thermal insulation materials reduce heat transfer. Specific steps include: mixing 3,3′,5,5′-tetramethylbiphenyl, N,N-dimethylformamide, and potassium carbonate; adding a chloroethoxyethanol solution; after post-treatment, mixing with dichloromethane; and adding a triethylamine and acryloyl chloride solution to prepare acryloyl-modified tetramethylbiphenyl; then stirring evenly with octadecyl acrylate, methyl methacrylate, polyethylene glycol monomethyl ether acrylate, and graphene, followed by ultrasonic dispersion; mixing paraffin wax with silica aerogel; and assembling the multilayer material after cooling.
It achieves high thermal conductivity of phase change materials and shape stability of insulation materials, improves the rapid transfer of battery heat and the reduction of heat between batteries, solves the leakage problem of phase change materials, and has excellent heat dissipation and insulation functions.
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Figure CN120986017A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of layered materials technology, specifically to a multilayer composite phase change thermal insulation sheet, its preparation method, and its application in battery thermal runaway protection. Background Technology
[0002] Battery thermal safety issues are usually related to thermal runaway. The main cause of thermal runaway is the exothermic chemical reaction that occurs in the battery and generates intense heat. If this heat cannot be dissipated in time, the battery temperature will rise rapidly. The temperature rise will cause more complex chemical reactions inside the battery, generating a large amount of heat, creating a vicious cycle that ultimately leads to thermal runaway.
[0003] The primary function of battery thermal management is to control the temperature of individual cells, battery modules, and battery packs within the required range and maintain uniform temperature distribution within the module under high charge / discharge rates and extreme external environmental conditions. Based on the cooling medium, thermal management systems can be categorized into air cooling, water cooling, phase change material cooling, and combinations thereof.
[0004] Adding a thermal barrier layer between adjacent cells is an effective way to prevent the spread of thermal runaway. Phase change material (PCM) cooling, as an innovative heat dissipation solution for battery systems, has become a research hotspot in recent years. PCM is a special functional material that has the ability to store a large amount of heat energy during phase change, absorbing / releasing latent heat while maintaining a relatively constant temperature. It is a suitable medium for heat energy storage and temperature control in the field of thermal management. However, most PCMs suffer from poor heat transfer and low thermal conductivity, directly affecting energy storage and release. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a multilayer composite phase change heat insulation sheet, a preparation method, and its application in battery thermal runaway protection. In the composite structure of the multilayer composite phase change heat insulation sheet, the phase change material plays a role in absorbing heat when the battery temperature rises, and its excellent thermal conductivity improves the heat dissipation capacity, enabling the rapid transfer of heat from the battery; the good thermal insulation performance of the heat insulation material achieves the purpose of reducing heat transfer between batteries, and can be applied to battery thermal runaway protection.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0007] A method for preparing a multilayer composite phase change heat insulation sheet includes the following steps:
[0008] Step (1): Mix 3,3′,5,5′-tetramethylbiphenyl and N,N-dimethylformamide, add potassium carbonate and mix well, add chloroethoxyethanol solution dropwise, after the addition is complete, react, after the reaction is complete, perform post-processing to obtain the intermediate product;
[0009] The intermediate product and dichloromethane were mixed, and a mixed solution of triethylamine and acryloyl chloride was added dropwise. After the addition was complete, the reaction was carried out. After the reaction was completed, post-treatment was performed to obtain acryloyl-modified tetramethylbiphenyl.
[0010] Step (2): Mix octadecyl acrylate and methyl methacrylate to obtain the matrix material, add acryloyl-modified tetramethyl biphenyl, polyethylene glycol monomethyl ether acrylate and initiator benzoyl peroxide, stir evenly, add graphene and continue stirring, ultrasonically disperse, dry in a mold to obtain the phase change material;
[0011] Step (3): Melt the paraffin wax, mix the silica aerogel with the melted paraffin wax, mix evenly, place in a mold to cool, and obtain the heat insulation material;
[0012] The layers of materials are assembled in the order of phase change material, heat insulation material, and phase change material to obtain a multilayer composite phase change heat insulation sheet.
[0013] Preferably, in step (1): the solid-liquid ratio of 3,3′,5,5′-tetramethylbiphenylhydroquinone and N,N-dimethylformamide is 10g:50-100mL; the dropwise addition conditions of the chloroethoxyethanol solution are: dropwise addition at 0℃ for 20-30min; the chloroethoxyethanol solution is prepared by mixing chloroethoxyethanol and N,N-dimethylformamide at a solid-liquid ratio of 10-15g:10-20mL; when preparing the intermediate product, the reaction conditions are: reaction at 0-5℃ for 1-2h, after the reaction is completed, the temperature is raised, and the reaction continues at 90-100℃ for 48-54h.
[0014] Preferably, in step (1): when preparing the intermediate product, the post-processing operation is as follows: cool to room temperature, filter, take the filtrate, add dichloromethane, wash with water, separate the liquid, take the organic phase, add anhydrous sodium sulfate to dry, and distill under reduced pressure.
[0015] Preferably, in step (1), the molar ratio of 3,3′,5,5′-tetramethylbiphenyl, potassium carbonate, chloroethoxyethanol, triethylamine, and acryloyl chloride is 4:8-12:8-12:8-12:8-12; and the solid-liquid ratio of the intermediate product and dichloromethane is 5g:10-20mL.
[0016] Preferably, in step (1), the dropping conditions for the mixed solution of triethylamine and acryloyl chloride are: dropping at 0℃ for 20-30 min; the mixed solution of triethylamine and acryloyl chloride is prepared by mixing triethylamine, acryloyl chloride, and dichloromethane at a solid-liquid ratio of 3g:2.7g:10mL; when preparing acryloyl-modified tetramethylbiphenyl, the reaction conditions are: reacting at 0℃ for 1-2 h, and after the reaction is completed, raising the temperature to 25-30℃ and continuing the reaction for 12-24 h.
[0017] Preferably, in step (1): when preparing acryloyl-modified tetramethylbiphenyl, the post-treatment operation is as follows: wash with 5wt% sodium hydroxide aqueous solution and water in sequence, separate the liquid, take the organic phase, add anhydrous sodium sulfate to dry, and distill under reduced pressure.
[0018] Preferably, in step (2): the molar ratio of octadecyl acrylate to methyl methacrylate is 5-10:1; the mass ratio of matrix material, acryloyl-modified tetramethylbiphenyl, polyethylene glycol monomethyl ether acrylate, initiator benzoyl peroxide, and graphene is 100:6-10:5-10:1-1.5:8-12; the stirring conditions are: stirring until homogeneous at 30-40℃; the continued stirring conditions are: continuing stirring at 30-40℃ for 0.5-1h; and the ultrasonic dispersion time is 1-2h.
[0019] Preferably, in step (3), the mixing conditions of silica aerogel and melted paraffin are: mixing at 80°C for 2-3 hours; the thickness of the phase change material is 3-5 mm, and the thickness of the heat insulation material is 2-3 mm.
[0020] Preferably, a multilayer composite phase change heat insulation sheet is prepared using the preparation method of the multilayer composite phase change heat insulation sheet described above.
[0021] Preferably, the application of a multilayer composite phase change thermal insulation sheet as described above in battery thermal runaway protection.
[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0023] 1. This invention combines thermal insulation materials and phase change materials to form a composite structure, enabling the multilayer composite phase change thermal insulation sheet to have both heat dissipation and thermal insulation functions. In this composite structure, the phase change material absorbs heat when the battery temperature rises, and its excellent thermal conductivity improves heat dissipation capacity, allowing the battery's heat to transfer rapidly. The thermal insulation material is prepared by dispersing paraffin wax in silica aerogel, which increases the shape stability of the paraffin phase change material, making it less prone to leakage of the phase change components in the thermal insulation material. Its excellent thermal insulation phase change performance achieves the purpose of reducing heat transfer between batteries.
[0024] 2. This invention introduces an acryloyl group onto tetramethylbiphenyl through a nucleophilic substitution reaction to obtain acryloyl-modified tetramethylbiphenyl with carbon-carbon double bonds, which can participate in the copolymerization reaction of acrylate monomers.
[0025] This invention introduces octadecyl acrylate, polyethylene glycol monomethyl ether acrylate, and acryloyl-modified tetramethylbiphenyl hydroquinone with a rigid biphenyl structure into a phase change material (PCM) via copolymerization. The resulting PCM not only possesses high latent heat and thermal conductivity, but the rigid biphenyl structure also enhances its thermal stability. Furthermore, the phase-changeable alkane and polyether side chains are chemically bonded to the rigid main chain, solving the leakage problem inherent in PCMs. The linear polymer main chain of the PCM imparts excellent molding and secondary processing properties, and the comb-like structure allows for freer nucleation / crystallization of the phase-change side chains, making it suitable for battery thermal management.
[0026] Furthermore, the introduction of acryloyl-modified tetramethylbiphenyl hydroquinone with a biphenyl structure into the phase change material allows for the formation of physical cross-linking points through π-π stacking interactions between molecular chains, thereby improving the mechanical properties of the phase change material. Graphene, on the other hand, can form π-π stacking interactions with the molecular chains of the phase change material, resulting in good dispersion of graphene within the material and the formation of effective thermal conductivity pathways, thus enhancing the thermal conductivity of the composite material. Attached Figure Description
[0027] Figure 1 This is a schematic diagram of the structure of the multilayer composite phase change heat insulation sheet prepared in this invention;
[0028] Figure 2 This is a schematic diagram of the reaction for synthesizing acryloyl-modified tetramethylbiphenyl in this invention;
[0029] Figure 3 This is a bar chart showing the thermal conductivity of the phase change materials prepared in Examples 1-5 and Comparative Examples 1-2 of this invention during performance testing.
[0030] Figure 4 This is a bar chart showing the mass retention rate of the phase change materials prepared in Examples 1-5 and Comparative Examples 1-2 of this invention during performance testing;
[0031] In the picture:
[0032] 1. Phase change materials; 2. Thermal insulation materials. Detailed Implementation
[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0034] Example 1
[0035] This embodiment discloses a method for preparing a multilayer composite phase change heat insulation sheet, including the following steps:
[0036] Step (1): Mix 3,3′,5,5′-tetramethylbiphenyl and N,N-dimethylformamide at a solid-liquid ratio of 10g:50mL, add potassium carbonate and mix well, add chloroethoxyethanol solution dropwise at 0℃ for 20min, after the addition is complete, react for 1h, after the reaction is complete, raise the temperature and continue the reaction at 100℃ for 48h, after the reaction is complete, cool to room temperature, filter, take the filtrate, add dichloromethane, wash with water, separate the liquid, take the organic phase, add anhydrous sodium sulfate to dry, and distill under reduced pressure to obtain the intermediate product;
[0037] The chloroethoxyethanol solution is prepared by mixing chloroethoxyethanol and N,N-dimethylformamide at a solid-liquid ratio of 15g:10mL.
[0038] The intermediate product and dichloromethane were mixed at a solid-liquid ratio of 5 g: 10 mL. A mixed solution of triethylamine and acryloyl chloride was added dropwise at 0 °C over 20 min. After the addition was complete, the reaction was allowed to proceed for 1 h. After the reaction was completed, the temperature was raised to 25 °C and the reaction was continued for 12 h. After the reaction was completed, the mixture was washed successively with 5 wt% sodium hydroxide aqueous solution and water. The mixture was separated, and the organic phase was dried with anhydrous sodium sulfate and distilled under reduced pressure to obtain acryloyl-modified tetramethylbiphenyl hydroquinone.
[0039] The molar ratio of 3,3′,5,5′-tetramethylbiphenyl, potassium carbonate, chloroethoxyethanol, triethylamine, and acryloyl chloride is 4:12:12:12:12; the mixed solution of triethylamine and acryloyl chloride is prepared by mixing triethylamine, acryloyl chloride, and dichloromethane at a solid-liquid ratio of 3g:2.7g:10mL.
[0040] Step (2): Mix octadecyl acrylate and methyl methacrylate to obtain the matrix material, add acryloyl-modified tetramethyl biphenyl, polyethylene glycol monomethyl ether acrylate and initiator benzoyl peroxide, stir evenly at 30°C, add graphene and continue stirring for 1 hour, ultrasonically disperse for 1 hour, pour into a mold and dry at 90°C for 20 minutes to obtain the phase change material;
[0041] The molar ratio of octadecyl acrylate to methyl methacrylate is 5:1; the mass ratio of matrix material, acryloyl-modified tetramethylbiphenyl, polyethylene glycol monomethyl ether acrylate, initiator benzoyl peroxide, and graphene is 100:6:5:1:8.
[0042] Step (3): Melt the paraffin at 60°C, mix the silica aerogel with the melted paraffin at 80°C for 2 hours, mix evenly, place in a mold and cool to room temperature to obtain the heat insulation material;
[0043] The layers of materials are assembled in the order of phase change material, heat insulation material, and phase change material to obtain a multi-layer composite phase change heat insulation sheet.
[0044] The phase change material has a thickness of 3 mm, and the thermal insulation material has a thickness of 2 mm.
[0045] Example 2
[0046] This embodiment discloses a method for preparing a multilayer composite phase change heat insulation sheet, including the following steps:
[0047] Step (1): Mix 3,3′,5,5′-tetramethylbiphenyl and N,N-dimethylformamide at a solid-liquid ratio of 10g:50mL, add potassium carbonate and mix well, add chloroethoxyethanol solution dropwise at 0℃ for 20min, after the addition is complete, react for 1h, after the reaction is complete, raise the temperature and continue the reaction at 100℃ for 48h, after the reaction is complete, cool to room temperature, filter, take the filtrate, add dichloromethane, wash with water, separate the liquid, take the organic phase, add anhydrous sodium sulfate to dry, and distill under reduced pressure to obtain the intermediate product;
[0048] The chloroethoxyethanol solution is prepared by mixing chloroethoxyethanol and N,N-dimethylformamide at a solid-liquid ratio of 15g:10mL.
[0049] The intermediate product and dichloromethane were mixed at a solid-liquid ratio of 5 g: 10 mL. A mixed solution of triethylamine and acryloyl chloride was added dropwise at 0 °C over 20 min. After the addition was complete, the reaction was allowed to proceed for 1.5 h. After the reaction was completed, the temperature was raised to 28 °C and the reaction was continued for 12 h. After the reaction was completed, the mixture was washed successively with 5 wt% sodium hydroxide aqueous solution and water. The liquid was separated, and the organic phase was dried with anhydrous sodium sulfate and distilled under reduced pressure to obtain acryloyl-modified tetramethylbiphenyl hydrophenol.
[0050] The molar ratio of 3,3′,5,5′-tetramethylbiphenyl, potassium carbonate, chloroethoxyethanol, triethylamine, and acryloyl chloride is 4:12:12:12:12; the mixed solution of triethylamine and acryloyl chloride is prepared by mixing triethylamine, acryloyl chloride, and dichloromethane at a solid-liquid ratio of 3g:2.7g:10mL.
[0051] Step (2): Mix octadecyl acrylate and methyl methacrylate to obtain the matrix material, add acryloyl-modified tetramethyl biphenyl, polyethylene glycol monomethyl ether acrylate and initiator benzoyl peroxide, stir evenly at 35°C, add graphene and continue stirring for 0.8h, ultrasonically disperse for 1.5h, pour into a mold and dry at 90°C for 20min to obtain the phase change material;
[0052] The molar ratio of octadecyl acrylate to methyl methacrylate is 6:1; the mass ratio of matrix material, acryloyl-modified tetramethylbiphenyl, polyethylene glycol monomethyl ether acrylate, initiator benzoyl peroxide, and graphene is 100:7:7:1.2:9.
[0053] Step (3): Melt the paraffin at 60°C, mix the silica aerogel with the melted paraffin at 80°C for 2.5 hours, mix evenly, place in a mold and cool to room temperature to obtain the heat insulation material;
[0054] The layers of materials are assembled in the order of phase change material, heat insulation material, and phase change material to obtain a multi-layer composite phase change heat insulation sheet.
[0055] The phase change material has a thickness of 3 mm, and the thermal insulation material has a thickness of 2 mm.
[0056] Example 3
[0057] This embodiment discloses a method for preparing a multilayer composite phase change heat insulation sheet, including the following steps:
[0058] Step (1): Mix 3,3′,5,5′-tetramethylbiphenyl and N,N-dimethylformamide at a solid-liquid ratio of 10g:50mL, add potassium carbonate and mix well, add chloroethoxyethanol solution dropwise at 0℃ for 20min, after the addition is complete, react for 1h, after the reaction is complete, raise the temperature and continue the reaction at 100℃ for 48h, after the reaction is complete, cool to room temperature, filter, take the filtrate, add dichloromethane, wash with water, separate the liquid, take the organic phase, add anhydrous sodium sulfate to dry, and distill under reduced pressure to obtain the intermediate product;
[0059] The chloroethoxyethanol solution is prepared by mixing chloroethoxyethanol and N,N-dimethylformamide at a solid-liquid ratio of 15g:10mL.
[0060] The intermediate product and dichloromethane were mixed at a solid-liquid ratio of 5 g: 10 mL. A mixed solution of triethylamine and acryloyl chloride was added dropwise at 0 °C over 20 min. After the addition was complete, the reaction was allowed to proceed for 1.5 h. After the reaction was completed, the temperature was raised to 28 °C and the reaction was continued for 12 h. After the reaction was completed, the mixture was washed successively with 5 wt% sodium hydroxide aqueous solution and water. The liquid was separated, and the organic phase was dried with anhydrous sodium sulfate and distilled under reduced pressure to obtain acryloyl-modified tetramethylbiphenyl hydrophenol.
[0061] The molar ratio of 3,3′,5,5′-tetramethylbiphenyl, potassium carbonate, chloroethoxyethanol, triethylamine, and acryloyl chloride is 4:12:12:12:12; the mixed solution of triethylamine and acryloyl chloride is prepared by mixing triethylamine, acryloyl chloride, and dichloromethane at a solid-liquid ratio of 3g:2.7g:10mL.
[0062] Step (2): Mix octadecyl acrylate and methyl methacrylate to obtain the matrix material, add acryloyl-modified tetramethyl biphenyl, polyethylene glycol monomethyl ether acrylate and initiator benzoyl peroxide, stir evenly at 35°C, add graphene and continue stirring for 0.8h, ultrasonically disperse for 1.5h, pour into a mold and dry at 90°C for 20min to obtain the phase change material;
[0063] The molar ratio of octadecyl acrylate to methyl methacrylate is 8:1; the mass ratio of matrix material, acryloyl-modified tetramethylbiphenyl, polyethylene glycol monomethyl ether acrylate, initiator benzoyl peroxide, and graphene is 100:8:8:1.3:10.
[0064] Step (3): Melt the paraffin at 60°C, mix the silica aerogel with the melted paraffin at 80°C for 2.5 hours, mix evenly, place in a mold and cool to room temperature to obtain the heat insulation material;
[0065] The layers of materials are assembled in the order of phase change material, heat insulation material, and phase change material to obtain a multi-layer composite phase change heat insulation sheet.
[0066] The phase change material has a thickness of 3 mm, and the thermal insulation material has a thickness of 2 mm.
[0067] Example 4
[0068] This embodiment discloses a method for preparing a multilayer composite phase change heat insulation sheet, including the following steps:
[0069] Step (1): Mix 3,3′,5,5′-tetramethylbiphenyl and N,N-dimethylformamide at a solid-liquid ratio of 10g:50mL, add potassium carbonate and mix well, add chloroethoxyethanol solution dropwise at 0℃ for 20min, after the addition is complete, react for 1h, after the reaction is complete, raise the temperature and continue the reaction at 100℃ for 48h, after the reaction is complete, cool to room temperature, filter, take the filtrate, add dichloromethane, wash with water, separate the liquid, take the organic phase, add anhydrous sodium sulfate to dry, and distill under reduced pressure to obtain the intermediate product;
[0070] The chloroethoxyethanol solution is prepared by mixing chloroethoxyethanol and N,N-dimethylformamide at a solid-liquid ratio of 15g:10mL.
[0071] The intermediate product and dichloromethane were mixed at a solid-liquid ratio of 5 g: 10 mL. A mixed solution of triethylamine and acryloyl chloride was added dropwise at 0 °C over 20 min. After the addition was complete, the reaction was allowed to proceed for 1.5 h. After the reaction was completed, the temperature was raised to 28 °C and the reaction was continued for 12 h. After the reaction was completed, the mixture was washed successively with 5 wt% sodium hydroxide aqueous solution and water. The liquid was separated, and the organic phase was dried with anhydrous sodium sulfate and distilled under reduced pressure to obtain acryloyl-modified tetramethylbiphenyl hydrophenol.
[0072] The molar ratio of 3,3′,5,5′-tetramethylbiphenyl, potassium carbonate, chloroethoxyethanol, triethylamine, and acryloyl chloride is 4:12:12:12:12; the mixed solution of triethylamine and acryloyl chloride is prepared by mixing triethylamine, acryloyl chloride, and dichloromethane at a solid-liquid ratio of 3g:2.7g:10mL.
[0073] Step (2): Mix octadecyl acrylate and methyl methacrylate to obtain the matrix material, add acryloyl-modified tetramethyl biphenyl, polyethylene glycol monomethyl ether acrylate and initiator benzoyl peroxide, stir evenly at 35°C, add graphene and continue stirring for 0.8h, ultrasonically disperse for 1.5h, pour into a mold and dry at 90°C for 20min to obtain the phase change material;
[0074] The molar ratio of octadecyl acrylate to methyl methacrylate is 9:1; the mass ratio of matrix material, acryloyl-modified tetramethylbiphenyl, polyethylene glycol monomethyl ether acrylate, initiator benzoyl peroxide, and graphene is 100:9:9:1.4:11.
[0075] Step (3): Melt the paraffin at 60°C, mix the silica aerogel with the melted paraffin at 80°C for 2.5 hours, mix evenly, place in a mold and cool to room temperature to obtain the heat insulation material;
[0076] The layers of materials are assembled in the order of phase change material, heat insulation material, and phase change material to obtain a multi-layer composite phase change heat insulation sheet.
[0077] The phase change material has a thickness of 3 mm, and the thermal insulation material has a thickness of 2 mm.
[0078] Example 5
[0079] This embodiment discloses a method for preparing a multilayer composite phase change heat insulation sheet, including the following steps:
[0080] Step (1): Mix 3,3′,5,5′-tetramethylbiphenyl and N,N-dimethylformamide at a solid-liquid ratio of 10g:50mL, add potassium carbonate and mix well, add chloroethoxyethanol solution dropwise at 0℃ for 20min, after the addition is complete, react for 1h, after the reaction is complete, raise the temperature and continue the reaction at 100℃ for 48h, after the reaction is complete, cool to room temperature, filter, take the filtrate, add dichloromethane, wash with water, separate the liquid, take the organic phase, add anhydrous sodium sulfate to dry, and distill under reduced pressure to obtain the intermediate product;
[0081] The chloroethoxyethanol solution is prepared by mixing chloroethoxyethanol and N,N-dimethylformamide at a solid-liquid ratio of 15g:10mL.
[0082] The intermediate product and dichloromethane were mixed at a solid-liquid ratio of 5 g: 10 mL. A mixed solution of triethylamine and acryloyl chloride was added dropwise at 0 °C over 20 min. After the addition was complete, the reaction was allowed to proceed for 2 h. After the reaction was completed, the temperature was raised to 30 °C and the reaction was continued for 12 h. After the reaction was completed, the mixture was washed successively with 5 wt% sodium hydroxide aqueous solution and water. The liquid was separated, and the organic phase was dried with anhydrous sodium sulfate and distilled under reduced pressure to obtain acryloyl-modified tetramethylbiphenyl hydroquinone.
[0083] The molar ratio of 3,3′,5,5′-tetramethylbiphenyl, potassium carbonate, chloroethoxyethanol, triethylamine, and acryloyl chloride is 4:12:12:12:12; the mixed solution of triethylamine and acryloyl chloride is prepared by mixing triethylamine, acryloyl chloride, and dichloromethane at a solid-liquid ratio of 3g:2.7g:10mL.
[0084] Step (2): Mix octadecyl acrylate and methyl methacrylate to obtain the matrix material, add acryloyl-modified tetramethyl biphenyl, polyethylene glycol monomethyl ether acrylate and initiator benzoyl peroxide, stir evenly at 40°C, add graphene and continue stirring for 0.5h, ultrasonically disperse for 2h, pour into a mold and dry at 90°C for 20min to obtain the phase change material;
[0085] The molar ratio of octadecyl acrylate to methyl methacrylate is 10:1; the mass ratio of matrix material, acryloyl-modified tetramethylbiphenyl, polyethylene glycol monomethyl ether acrylate, initiator benzoyl peroxide, and graphene is 100:10:10:1.5:12.
[0086] Step (3): Melt the paraffin at 60°C, mix the silica aerogel with the melted paraffin at 80°C for 3 hours, and after mixing evenly, place it in a mold and cool it to room temperature to obtain the heat insulation material.
[0087] The layers of materials are assembled in the order of phase change material, heat insulation material, and phase change material to obtain a multi-layer composite phase change heat insulation sheet.
[0088] The phase change material has a thickness of 3 mm, and the thermal insulation material has a thickness of 2 mm.
[0089] Comparative Example 1
[0090] This comparative example discloses a method for preparing a multilayer composite phase change heat insulation sheet, including the following steps:
[0091] Step (1): Mix octadecyl acrylate and methyl methacrylate to obtain the matrix material, add polyethylene glycol monomethyl ether acrylate and benzoyl peroxide initiator, stir evenly at 30°C, add graphene and continue stirring for 1 hour, ultrasonically disperse for 1 hour, pour into a mold and dry at 90°C for 20 minutes to obtain the phase change material.
[0092] The molar ratio of octadecyl acrylate to methyl methacrylate is 5:1; the mass ratio of matrix material, polyethylene glycol monomethyl ether acrylate, initiator benzoyl peroxide, and graphene is 100:5:1:8.
[0093] Step (2): Melt the paraffin at 60°C, mix the silica aerogel with the melted paraffin at 80°C for 2 hours, and after mixing evenly, place it in a mold and cool it to room temperature to obtain the heat insulation material.
[0094] The layers of materials are assembled in the order of phase change material, heat insulation material, and phase change material to obtain a multi-layer composite phase change heat insulation sheet.
[0095] The phase change material has a thickness of 3 mm, and the thermal insulation material has a thickness of 2 mm.
[0096] Comparative Example 2
[0097] This comparative example discloses a method for preparing a multilayer composite phase change heat insulation sheet, including the following steps:
[0098] Step (1): Mix 3,3′,5,5′-tetramethylbiphenyl and N,N-dimethylformamide at a solid-liquid ratio of 10g:50mL, add potassium carbonate and mix well, add chloroethoxyethanol solution dropwise at 0℃ for 20min, after the addition is complete, react for 1h, after the reaction is complete, raise the temperature and continue the reaction at 100℃ for 48h, after the reaction is complete, cool to room temperature, filter, take the filtrate, add dichloromethane, wash with water, separate the liquid, take the organic phase, add anhydrous sodium sulfate to dry, and distill under reduced pressure to obtain the intermediate product;
[0099] The chloroethoxyethanol solution is prepared by mixing chloroethoxyethanol and N,N-dimethylformamide at a solid-liquid ratio of 15g:10mL.
[0100] The intermediate product and dichloromethane were mixed at a solid-liquid ratio of 5 g: 10 mL. A mixed solution of triethylamine and acryloyl chloride was added dropwise at 0 °C over 20 min. After the addition was complete, the reaction was allowed to proceed for 1 h. After the reaction was completed, the temperature was raised to 25 °C and the reaction was continued for 12 h. After the reaction was completed, the mixture was washed successively with 5 wt% sodium hydroxide aqueous solution and water. The mixture was separated, and the organic phase was dried with anhydrous sodium sulfate and distilled under reduced pressure to obtain acryloyl-modified tetramethylbiphenyl hydroquinone.
[0101] The molar ratio of 3,3′,5,5′-tetramethylbiphenyl, potassium carbonate, chloroethoxyethanol, triethylamine, and acryloyl chloride is 4:12:12:12:12; the mixed solution of triethylamine and acryloyl chloride is prepared by mixing triethylamine, acryloyl chloride, and dichloromethane at a solid-liquid ratio of 3g:2.7g:10mL.
[0102] Step (2): Mix octadecyl acrylate and methyl methacrylate to obtain the matrix material, add acryloyl-modified tetramethyl biphenyl, polyethylene glycol monomethyl ether acrylate and initiator benzoyl peroxide, stir evenly at 30°C, continue stirring for 1 hour, pour into a mold and dry at 90°C for 20 minutes to obtain the phase change material.
[0103] The molar ratio of octadecyl acrylate to methyl methacrylate is 5:1; the mass ratio of matrix material, acryloyl-modified tetramethylbiphenyl, polyethylene glycol monomethyl ether acrylate, and initiator benzoyl peroxide is 100:6:5:1.
[0104] Step (3): Melt the paraffin at 60°C, mix the silica aerogel with the melted paraffin at 80°C for 2 hours, mix evenly, place in a mold and cool to room temperature to obtain the heat insulation material;
[0105] The layers of materials are assembled in the order of phase change material, heat insulation material, and phase change material to obtain a multi-layer composite phase change heat insulation sheet.
[0106] The phase change material has a thickness of 3 mm, and the thermal insulation material has a thickness of 2 mm.
[0107] In the above examples and comparative examples: the molecular weight of polyethylene glycol monomethyl ether acrylate is 1000; the graphene has a size of 3-8 μm and a tap density of 0.1-0.5 g / cm³. 3 The paraffin wax is model OP44E, and its phase transition temperature is 44℃.
[0108] Test case
[0109] The phase change materials from the multilayer composite phase change heat insulation sheets prepared in Examples 1-5 and Comparative Examples 1-2 were designated as Samples 1-7, and their thermal conductivity, phase change performance, and leakage resistance were tested. The heat insulation materials from the multilayer composite phase change heat insulation sheets prepared in Examples 1-5 and Comparative Examples 1-2 were designated as Specimens 1-7, and their thermal conductivity and leakage resistance were tested. The specific test results are shown in Tables 1 and 2.
[0110] Table 1
[0111]
[0112]
[0113] Table 2
[0114] Thermal conductivity (W / m / K) Quality retention rate (%) Sample 1 0.10 98.3 Sample 2 0.10 98.2 Sample 3 0.09 98.5 Sample 4 0.09 98.4 Sample 5 0.09 98.2 Sample 6 0.10 98.2 Sample 7 0.10 98.3
[0115] The tests for each indicator in Tables 1 and 2 were conducted according to the following standards: thermal conductivity (W / m / K) was measured by a thermal conductivity meter; latent heat of phase change was measured by a differential scanning calorimeter, with a temperature range of 0-80℃ and a heating rate of 5℃ / min; leakage resistance was represented by the mass retention rate, and the test method was as follows: samples 1-7 were placed in a constant temperature chamber to simulate the heat absorption and release process, heated to 70℃ and held for 1 hour, then cooled to 30℃ and held for 1 hour, and the experiment was repeated 100 times. The remaining mass of the samples was recorded and the mass retention rate was calculated.
[0116] As shown in Table 1, the phase change material prepared by this invention exhibits excellent thermal conductivity, and the thermal insulation material demonstrates excellent thermal insulation performance. Both materials exhibit shape stability and strong anti-leakage properties. This is because, during the preparation of the phase change material, this invention introduces octadecyl acrylate, polyethylene glycol monomethyl ether acrylate, and acryloyl-modified tetramethylbiphenyl diphenol with a rigid biphenyl structure into the phase change material via copolymerization. The resulting phase change material not only possesses high latent heat and thermal conductivity, but the rigid biphenyl structure also enhances the material's heat resistance. Furthermore, the phase-changeable alkane and polyether side chains are chemically bonded to the rigid main chain, solving the problem of easy leakage in phase change materials. The linear polymer main chain of the phase change material endows it with excellent molding and secondary processing properties, and the comb-like structure allows for more free nucleation / crystallization of the phase change side chains. Moreover, the introduction of acryloyl-modified tetramethylbiphenyl diphenol with a biphenyl structure into the phase change material allows for the formation of physical cross-linking points through π-π stacking interactions between molecular chains, improving the mechanical properties of the phase change material. Graphene can form π-π stacking interactions with the molecular chains of phase change materials, resulting in good dispersion of graphene within the phase change material and creating effective thermal conductivity pathways, thereby improving the thermal conductivity of the composite material. In the preparation of thermal insulation materials, dispersing paraffin wax in silica aerogel can increase the shape stability of the paraffin phase change material, making it less prone to leakage of the phase change components in the thermal insulation material.
[0117] Comparative Example 1, lacking acryloyl-modified tetramethylbiphenyl, suffers from a lack of π-π stacking interactions between molecular chains and between graphene and the phase change material's molecular chains. This results in decreased graphene dispersion within the phase change material, leading to lower thermal conductivity compared to the examples. Similarly, Comparative Example 2, also lacking graphene, lacks the thermal conductivity pathways formed by graphene within the phase change material, resulting in decreased thermal conductivity for sample 2.
[0118] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A method for preparing a multilayer composite phase change thermal insulation sheet, characterized by, Comprise the following steps: Step (1), octadecyl acrylate, methyl methacrylate is mixed to obtain the base material, acryl modified tetramethyl diphenol, polyethylene glycol monomethyl ether acrylate, initiator benzoyl peroxide is added, stirring is uniform, continue stirring after adding graphene, ultrasonic dispersion, drying in the mold, the phase change material is obtained; Step (2), the paraffin is melted, the silica aerogel is mixed with the melted paraffin, after mixing uniformly, it is placed in a mold and cooled to obtain a thermal insulation material; The materials of each layer are assembled in the order of phase change material, thermal insulation material and phase change material to obtain a multilayer composite phase change thermal insulation sheet.
2. The method for preparing the multilayer composite phase change heat insulation sheet according to claim 1, characterized in that, The acryl modified tetramethyl diphenol in step (1) is prepared by the following steps: S1, 3, 3', 5, 5'-tetramethyl diphenol, N, N-dimethylformamide is mixed, potassium carbonate is added and mixed uniformly, chloroethoxy ethanol solution is added dropwise, after dropwise addition is completed, reaction, after reaction is completed, post-treatment, the intermediate product is obtained; S2, the intermediate product, dichloromethane is mixed, a mixed solution of triethylamine and acryloyl chloride is added dropwise, after dropwise addition is completed, reaction, after reaction is completed, post-treatment, acryl modified tetramethyl diphenol is obtained.
3. The method for preparing the multilayer composite phase change heat insulation sheet according to claim 2, characterized in that, When preparing the acryl modified tetramethyl diphenol in step (1): In S1: the solid-liquid ratio of 3, 3', 5, 5'-tetramethyl diphenol and N, N-dimethylformamide is 10g:50-100mL; the dropwise addition condition of chloroethoxy ethanol solution is: dropwise addition for 20-30min at 0℃; the chloroethoxy ethanol solution is prepared by mixing chloroethoxy ethanol and N, N-dimethylformamide with a solid-liquid ratio of 10-15g:10-20mL.
4. The method for preparing the multilayer composite phase change heat insulation sheet according to claim 2, characterized in that, When preparing the acryl modified tetramethyl diphenol in step (1): In S1: the reaction condition is: reaction for 1-2h at 0-5℃, after reaction is completed, temperature is raised, and reaction is continued for 48-54h at 90-100℃.
5. The method for preparing the multilayer composite phase change heat insulation sheet according to claim 2, characterized in that, When preparing the acryl modified tetramethyl diphenol in step (1): In S2: the molar ratio of 3, 3', 5, 5'-tetramethyl diphenol, potassium carbonate, chloroethoxy ethanol, triethylamine and acryloyl chloride is 4:8-12:8-12:8-12:8-12; the solid-liquid ratio of the intermediate product and dichloromethane is 5g:10-20mL.
6. The method for preparing the multilayer composite phase change heat insulation sheet according to claim 2, characterized in that, When preparing the acryl modified tetramethyl diphenol in step (1): In S2: the dropwise addition condition of the mixed solution of triethylamine and acryloyl chloride is: dropwise addition for 20-30min at 0℃; the mixed solution of triethylamine and acryloyl chloride is prepared by mixing triethylamine, acryloyl chloride and dichloromethane with a solid-liquid ratio of 3g:2.7g:10mL; the reaction condition is: reaction for 1-2h at 0℃, after reaction is completed, temperature is raised to 25-30℃, and reaction is continued for 12-24h.
7. The method for preparing the multilayer composite phase change heat insulation sheet according to claim 1, characterized in that, In the step (1), the molar ratio of octadecyl acrylate and methyl methacrylate is 5-10:1; the mass ratio of the matrix material, acryloyl-modified tetramethyl diphenol, polyethylene glycol monomethyl ether acrylate, initiator benzoyl peroxide and graphene is 100:6-10:5-10:1-1.5:8-12; the stirring condition is uniform stirring at a temperature of 30-40℃; the continuous stirring condition is continuous stirring at a temperature of 30-40℃ for 0.5-1h; and the ultrasonic dispersion time is 1-2h.
8. The method for preparing the multilayer composite phase change heat insulation sheet according to claim 1, characterized in that, In the step (2), the mixing condition of the silica aerogel and the melted paraffin is mixing at a temperature of 80℃ for 2-3h; the thickness of the phase change material is 3-5mm, and the thickness of the thermal insulation material is 2-3mm. 9.A multilayer composite phase change thermal insulation sheet prepared by a preparation method of the multilayer composite phase change thermal insulation sheet according to any one of claims 1-8. 10.The application of the multilayer composite phase change thermal insulation sheet according to claim 9 in battery thermal runaway protection.