A heat dissipation and resistance composite material, a preparation method and application thereof, and a battery system

Abstract

The application belongs to the technical field of heat-resistant materials, and particularly relates to a heat-dissipation and heat-resistance composite material, a preparation method and application thereof, and a battery system. The heat-dissipation and heat-resistance composite material comprises a heat-resistant material and an insulating film coated on the surface of the heat-resistant material. The heat-resistant material comprises porous aramid material and composite filler filled in the pores of the porous aramid material. According to the mass percentage, the composite filler comprises 20-50% of heat-conducting phase change capsules and 50-80% of heat insulation materials. The core material of the heat-conducting phase change capsule is a heat-conducting phase change material. The heat-dissipation and heat-resistance composite material has the dual functions of heat dissipation and heat insulation, can absorb and block the heat generated by thermal runaway of battery monomers, solves the contradiction between heat dissipation and thermal runaway blocking of the power battery system, and makes the two functions synergistic, so as to effectively inhibit and delay the propagation of thermal runaway in the power battery system.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of heat-resistant materials, and particularly relates to a heat-dissipating and heat-resisting composite material, a preparation method and application thereof, and a battery system. BACKGROUND

[0002] As an energy carrier, the chemical activity of power batteries is improved with the increase of energy density. While pursuing the convenience brought by high energy density of power batteries, the safety hazards become increasingly prominent. During the charging and discharging process of the battery, a large amount of heat is generated, and combined with the effects of space limitation and time accumulation, the temperature of the battery is prone to abnormally rise. After thermal runaway is triggered, the heat released by the local battery monomer will spread to the surrounding, which may heat the surrounding battery and cause thermal runaway of the surrounding battery, and finally cause serious accidents such as fire and explosion. Therefore, it is of great significance to carry out safety protection design of power battery thermal runaway.

[0003] At present, power batteries mainly inhibit the spread of battery thermal runaway by arranging heat insulation materials between battery monomers. When a certain battery monomer occurs thermal runaway, the heat released by the battery is limited in the battery to avoid the heat generated by thermal runaway from being transmitted to the adjacent battery. However, the heat insulation material only plays a role in blocking heat transfer and cannot effectively absorb and transfer heat. At the same time, after adding the heat insulation material, the heat dissipation performance of the power battery system at normal temperature is affected, which is prone to cause uneven temperature distribution of the battery and has potential risk of thermal runaway.

[0004] The related technology provides an aerosol honeycomb plate, which comprises a honeycomb ceramic layer and a fire extinguishing agent filled in the ceramic layer. The method aims to use the aerosol fire extinguishing agent in the cavity of the honeycomb ceramic to absorb the high-temperature substances sprayed out by the explosion-proof valve when the battery monomer occurs thermal runaway, so as to avoid the high-temperature substances from splashing on the surrounding battery and causing fire. However, the method only plays a role in extinguishing fire for the local monomer after the occurrence of battery thermal runaway, and does not control the heat transfer path of the battery, and does not play a role in heat dissipation and heat insulation before and during the thermal runaway. SUMMARY

[0005] The present application provides a kind of heat-dissipating and heat-resisting composite material and its preparation method and application, battery system, and the heat-dissipating and heat-resisting composite material provided by the present application has excellent heat dissipation and heat resistance performance.

[0006] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0007] The present application provides a kind of heat-dissipating and heat-resisting composite material, which comprises a heat-resistant material and an insulating film coated on the surface of the heat-resistant material.

[0008] The heat-resistant material comprises a porous aramid material and a composite filler filled in the pores of the porous aramid material; the composite filler comprises, in terms of mass percentage, 20-50% of the heat-conductive phase change capsule and 50-80% of the heat-insulating material; and the core material of the heat-conductive phase change capsule is a heat-conductive phase change material.

[0009] Preferably, the mass ratio of the porous aramid material and the composite filler is 20-25:1.

[0010] Preferably, the heat-insulating material comprises one or more of hollow glass microbeads, ceramic nanofiber aerogel and silica aerogel; and the particle size of the heat-insulating material is 10-250 μm.

[0011] Preferably, the particle size of the heat-conductive phase change capsule is 1-100 μm; the phase change temperature of the core material of the heat-conductive phase change capsule is 40-60℃; the wall material of the heat-conductive phase change capsule comprises silica and / or titanium dioxide; and the wall thickness of the heat-conductive phase change capsule is 0.01-10 μm.

[0012] Preferably, the emulsifier comprises an anionic surfactant type emulsifier and / or a non-ionic surfactant type emulsifier; and the mass of the emulsifier is 1-2% of the mass of the core material.

[0013] The pH of the acidic condition is 2-3; and the mass ratio of the core material and the titanium source is 1:1-3.

[0014] Preferably, the density of the porous aramid material is 0.03-0.2 g / cm 3 , and the thickness is 2-3 mm.

[0015] The pores of the porous aramid material penetrate along the thickness direction; the pores are hexagonal prism type, quadrangular prism type or cylindrical type; and the pore size is 1-4 mm.

[0016] Preferably, the insulation film comprises an aluminum plastic film, a high-temperature nylon film or a polyimide film; and the thickness of the insulation film is 0.075-0.25 mm.

[0017] The application further provides a preparation method of the heat-dissipating and heat-resistant composite material.

[0018] Mixing the heat-conductive phase change capsule and the heat-insulating material to obtain a composite filler;

[0019] Filling the composite filler in the pores of the porous aramid material to obtain a heat-resistant material;

[0020] Packaging the heat-resistant material with an insulation film to obtain the heat-dissipating and heat-resistant composite material.

[0021] The application further provides application of the heat dissipation and resistance composite material in a battery system.

[0022] The application further provides a battery system, which comprises battery cells and heat dissipation and resistance composite materials arranged alternately.

[0023] The application provides a heat dissipation and resistance composite material, which comprises a heat resistance material and an insulating film coated on the surface of the heat resistance material. The heat dissipation and resistance composite material provided by the application has good heat dissipation and heat absorption capacity, can effectively ensure that the battery works within a normal temperature range, and greatly improves temperature uniformity. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the application or in the prior art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can be obtained based on these drawings without creative labor.

[0025] Figure 1 A battery system provided by the application is shown in the figure, wherein 1 is a heat dissipation and resistance composite material, and 2 is a battery cell.

[0026] Figure 2 A section view of the heat dissipation and resistance composite material provided by the embodiment of the application along the thickness direction is shown in the figure, wherein 3 is a heat resistance material, and 5 is an insulating film.

[0027] Figure 3 A structure view of the heat resistance material provided by the embodiment of the application is shown in the figure, wherein 3 is a heat resistance material, 6 is a honeycomb hole of the porous aramid material, and 4 is a composite filler. DETAILED DESCRIPTION

[0028] The present application provides a heat dissipation and insulation composite material, comprising a heat insulation material and an insulation film coated on the surface of the heat insulation material.

[0029] The heat insulation material comprises porous aramid material and composite filler filled in the pores of the porous aramid material; the composite filler comprises 20-50% of heat-conductive phase change capsules and 50-80% of heat insulation material by mass percentage; the core material of the heat-conductive phase change capsule is heat-conductive phase change material.

[0030] In the present application, all raw material components are commercially available products well known to those skilled in the art, unless otherwise specified.

[0031] In the present application, the insulation film preferably comprises aluminum plastic film, high-temperature nylon film or polyimide film, and in specific embodiments, the insulation film is aluminum plastic film; the thickness of the insulation film is preferably 0.075-0.25 mm, and in specific embodiments, the thickness of the insulation film can be 0.075 mm, 0.1 mm, 0.15 mm, 0.2 mm or 0.25 mm. The insulation film wraps and protects the porous aramid material and the composite filler, and when the heat-conductive phase change capsules in the composite filler absorb a large amount of heat and phase change, the insulation film is broken under pressure to release the vaporized heat-conductive phase change material.

[0032] The composite filler comprises 20-50% of the heat-conducting phase change capsule in terms of mass percentage, and in specific embodiments, the mass percentage of the heat-conducting phase change capsule can be 20%, 30%, 40% or 50%; the particle size of the heat-conducting phase change capsule is preferably 1-100 μm, and in specific embodiments, the particle size of the heat-conducting phase change capsule can be 10 μm, 20 μm, 35 μm, 50 μm, 80 μm or 100 μm; the core material of the heat-conducting phase change capsule can have a phase change temperature of 40-60°C, and in specific embodiments, the core material can have a phase change temperature of 50°C; the core material of the heat-conducting phase change capsule preferably comprises one or more of paraffin, n-octadecane and n-docosane, and in specific embodiments, the core material of the heat-conducting phase change capsule can be paraffin, n-octadecane or n-docosane; the wall material preferably comprises silicon dioxide and / or titanium dioxide; and the wall thickness of the heat-conducting phase change capsule is preferably 0.01-10 μm, and in specific embodiments, the wall thickness of the heat-conducting phase change capsule can be 1 μm, 3 μm, 4 μm, 5 μm, 8 μm or 10 μm. The microcapsule has a clear core-shell structure, and the core material is a heat-conducting phase change material with a high latent heat value. When the core material reaches the phase change temperature, it can rapidly vaporize and absorb a large amount of heat, and release the heat to the surrounding environment. The wall material has the advantages of chemical stability, non-toxicity, harmlessness and high thermal conductivity, and by coating the wall material on the surface of the internal core material, the core material leakage can be prevented and the spherical structure can be maintained, thereby solving the problems of instability and leakage risk of the heat-conducting phase change material. If the mass percentage of the heat-conducting phase change capsule is less than the above range, the desired heat-conducting and heat-absorbing effects cannot be achieved. Specifically, when used in a high-power electric vehicle equipped with a high-energy-density power battery such as NCM811, the content of the heat-conducting phase change capsule in the composite filler can be greater than 40 wt% to meet the higher heat dissipation requirement of the power battery system. When used in a low-speed electric passenger vehicle, a park / attraction sightseeing vehicle, a logistics vehicle or other electric vehicles with lower power requirements, the content of the heat-conducting phase change capsule in the composite filler can be close to 20 wt%, but should not be less than 20 wt% to achieve the basic heat-conducting function.

[0033] In the present application, the preparation method of the heat-conducting phase change capsule preferably comprises the following steps:

[0034] Mixing the core material, the emulsifier and the solvent to obtain a phase change emulsion;

[0035] Mixing the phase change emulsion and a titanium source or a silicon source under acidic conditions to obtain a gel precipitate;

[0036] Drying the gel precipitate to obtain the heat-conducting phase change capsule.

[0037] The present application mixes core material, emulsifier and solvent to obtain phase change emulsion. In the present application, the emulsifier preferably includes anionic surfactant emulsifier and / or non-ionic surfactant emulsifier; the anionic surfactant emulsifier preferably includes sodium dodecyl sulfate and / or sodium alginate; the non-ionic surfactant emulsifier is preferably alkyl phenol polyoxyethylene ether; in specific embodiments, the emulsifier can be sodium dodecyl sulfate, sodium alginate or alkyl phenol polyoxyethylene ether; the mass of the emulsifier is preferably 1-2% of the mass of the core material; the solvent is preferably deionized water or formamide; in specific embodiments, the solvent can be formamide; the mass-volume ratio of the core material and solvent is preferably 10-30g:100-150mL; in specific embodiments, the mass-volume ratio of the core material and solvent can be 10g:100mL, 10g:150mL, 20g:100mL, 20g:150mL, 30g:100mL or 30g:150mL; the mixing method is preferably stirring; the stirring speed is preferably 200-1000rpm; in specific embodiments, the stirring speed can be 200rpm, 600rpm or 1000rpm; the temperature is preferably 60-75℃; in specific embodiments, the stirring temperature can be 60℃, 65℃ or 75℃; the time is preferably 1-2h. The mixing function is to obtain a uniform and stable phase change emulsion.

[0038] After obtaining the phase change emulsion, the present application mixes the phase change emulsion and titanium source under acidic conditions to obtain gel precipitation. In the present application, the pH of the acidic conditions is preferably 2-3; the reagent for providing the acidic conditions is preferably sulfuric acid or hydrochloric acid; in specific embodiments, the reagent for providing the acidic conditions can be hydrochloric acid; the mass fraction of the sulfuric acid is preferably 10%-20%; the mass fraction of the hydrochloric acid is preferably 36%-38%; the titanium source is preferably titanyl sulfate, tetraisopropyl titanate or tetrabutyl titanate; the silicon source is preferably tetramethyl orthosilicate, sodium silicate or ethyl orthosilicate; the mass ratio of the core material and titanium source is preferably 1:1-3; in specific embodiments, the mass ratio of the core material and tetrabutyl titanate can be 1:1, 1:2 or 1:3; the mixing method is preferably stirring; the stirring speed is preferably 200-1000rpm; in specific embodiments, the stirring speed can be 200rpm, 600rpm or 1000rpm; the temperature is preferably 60-75℃; in specific embodiments, the stirring temperature can be 60℃, 65℃ or 75℃; the present application has no special requirements for the mixing time, as long as the mixing system is gel-like; the mixing is followed by filtration; the filtration equipment is a vacuum pump. The filtration function is to obtain gel precipitation.

[0039] After obtaining the gel precipitate, the gel precipitate is dried to obtain the heat-conducting phase change capsule. In the present application, the drying is preferably preceded by cleaning; the cleaning preferably comprises deionized water cleaning and anhydrous ethanol cleaning; the cleaning serves to ensure that the final product has high purity; the drying is preferably natural drying, and the time is preferably 24-48h, and in specific embodiments, the drying time can be 24h, 36h or 48h.

[0040] The preparation method of the heat-conducting phase change capsule provided by the present application encapsulates the heat-conducting phase change material as the core material, and makes the heat-conducting phase change material into a solid powder by microencapsulation.

[0041] The composite filler comprises 50-80% of the heat-insulating material by mass percentage, and in specific embodiments, the mass percentage of the heat-insulating material can be 50%, 60%, 70% or 80%; the heat-insulating material preferably comprises one or more of hollow glass microbeads, ceramic nanofiber aerogel and silica aerogel; the particle size of the heat-insulating material is preferably 10-250μm, and in specific embodiments, the particle size of the heat-insulating material can be 50μm, 100μm, 200μm or 250μm; when the particle size of the heat-insulating material is greater than the above range, it is also preferable to include crushing the heat-insulating material; the crushing equipment is preferably a high-pressure grinding mill; the particle size of the hollow glass microbeads is preferably 10-250μm, and in specific embodiments, the particle size of the hollow glass microbeads can be 10μm, 100μm, 200μm or 250μm; the wall thickness is preferably 1-2μm; the density is preferably 0.1-0.6g / cm 3 , and in specific embodiments, the density of the hollow glass microbeads can be 0.1g / cm 3 , 0.4g / cm 3 or 0.6g / cm 3 . The heat-insulating material solves the problem of insufficient heat-insulating performance of the porous aramid material, wherein the hollow glass microbeads are hollow spherical inorganic non-metals, and the main components thereof include silicon dioxide, aluminum oxide and boron oxide, and the weight increase of the porous aramid material is limited.

[0042] In the present application, the density of the porous aramid material is preferably 0.03-0.2g / cm 3 , and in specific embodiments, it can be 0.05g / cm 3 , 0.1g / cm 3; the thickness is preferably 2-3 mm; the holes of the porous aramid material preferably extend along the thickness direction; the holes are preferably hexagonal prism, quadrangular prism or cylindrical, and in specific embodiments, the holes can be hexagonal prism; the hole diameter is preferably 1-4 mm, and in specific embodiments, the hole diameter can be 1 mm, 2 mm, 3 mm or 4 mm; the mass ratio of the porous aramid material and the composite filler is preferably 20-25:1, and in specific embodiments, the mass ratio of the porous aramid plate and the composite filler can be 20:1, 22:1 or 25:1. The raw materials for preparing the porous aramid material include aramid fibers, phenolic resin, epoxy resin, polyester resin, etc., and the porous aramid material is prepared through steps such as stretching, setting, impregnation and curing, and has the advantages of light weight, high mechanical strength, good flame retardance and high temperature resistance.

[0043] The heat dissipation and heat blocking composite material provided by the application has the following advantages: in the early stage of battery thermal runaway evolution (temperature < 100℃), the heat-conducting phase change capsules filled in the porous aramid material have a high thermal conductivity, can effectively dissipate heat of the thermal runaway monomer and avoid continuous accumulation of heat. When the temperature of the thermal runaway monomer reaches the phase change temperature of the heat-conducting phase change capsules, the phase change material can absorb a large amount of heat through the phase change process and release the heat to the surrounding environment. Meanwhile, after the heat-conducting phase change capsules are consumed, the heat insulation material can further block the remaining heat in cooperation with the porous aramid material, so that the heat generated by the battery thermal runaway is limited in a single battery, thereby inhibiting the thermal runaway propagation of the power battery system. The above process realizes the dual functions of low-temperature heat conduction and high-temperature heat insulation of the heat dissipation and heat blocking composite material, and under the dual actions of heat dissipation and heat insulation, the heat dissipation and heat blocking composite material can absorb and block the heat generated by the battery monomer due to thermal runaway, solves the contradiction between heat dissipation and thermal runaway blocking of the power battery system, and makes the two functions synergistically act to effectively inhibit and delay the thermal runaway propagation in the power battery system.

[0044] The application further provides a preparation method of the heat dissipation and heat blocking composite material.

[0045] The heat-conducting phase change capsules and the heat insulation material are mixed to obtain a composite filler.

[0046] The composite filler is filled into the holes of the porous aramid material to obtain a heat blocking material.

[0047] The heat blocking material is packaged with an insulating film to obtain the heat dissipation and heat blocking composite material.

[0048] The heat-conducting phase change capsules and the heat insulation material are mixed to obtain a composite filler. The mixing process is not particularly limited in the application, and the composite filler can be uniformly mixed by using a mixing method known to those skilled in the art.

[0049] After obtaining the composite filler, the composite filler is filled into the pores of the porous aramid material to obtain the heat-resistant material. In the present application, the filling is preferably preceded by encapsulating one side of the porous aramid material; the encapsulation is preferably by adhesion; the adhesion agent is preferably a structural adhesive; and the filling is preferably by hand or by machine. The encapsulation of one side prevents leakage of the filled composite filler.

[0050] After obtaining the heat-resistant material, the heat-resistant material is encapsulated with an insulating film to obtain the heat-dissipating and heat-resistant composite material. In the present application, the encapsulation is preferably by adhesion; and the adhesion agent is preferably a structural adhesive.

[0051] The present application also provides the use of the heat-dissipating and heat-resistant composite material of the above technical solution or the heat-dissipating and heat-resistant composite material obtained by the preparation method of the above technical solution in a battery system.

[0052] The present application applies the heat-dissipating and heat-resistant composite material to a battery system, which can be used for heat dissipation and prevention of heat runaway propagation in a power battery system, significantly improving the mass energy density and volume energy density of the battery pack under the premise of ensuring the safety of the battery pack.

[0053] The present application also provides a battery system comprising battery monomers and heat-dissipating and heat-resistant composite materials arranged alternately; the heat-dissipating and heat-resistant composite material is the heat-dissipating and heat-resistant composite material of the above technical solution or the heat-dissipating and heat-resistant composite material obtained by the preparation method of the above technical solution.

[0054] In order to further illustrate the present application, the heat-dissipating and heat-resistant composite material, the preparation method and application thereof, and the battery system provided by the present application are described in detail below with reference to the accompanying drawings and examples, but they should not be construed as limiting the scope of protection of the present application.

[0055] Figure 1 The battery system provided by the present application is shown in the schematic diagram, wherein 1 is the heat-dissipating and heat-resistant composite material, and 2 is the battery monomer. As shown in the figure, Figure 1 The present application provides a heat-dissipating and heat-resistant composite material for heat dissipation and prevention of heat runaway propagation in a power battery system, which is tightly installed in the gap formed between adjacent battery monomers, the heat-dissipating and heat-resistant composite material and the battery monomer are arranged alternately, and the maximum side surface of the battery monomer is in close contact with the working surface of the honeycomb composite structure.

[0056] Figure 2 The cross-sectional view of the heat-dissipating and heat-resistant composite material provided by the present application along the thickness direction is shown in the schematic diagram, wherein 3 is the heat-resistant material, and 5 is the insulating film; Figure 3 The structure of the heat-resistant material provided by the present application is shown in the schematic diagram, wherein 3 is the heat-resistant material, 6 is the honeycomb-shaped pore of the porous aramid material, and 4 is the composite filler.Figures 2-3 As shown, the heat dissipation and heat insulation composite material comprises a porous aramid material, a composite filler and an insulating film. The porous aramid material is arranged with a plurality of honeycomb holes, and the honeycomb holes are hollow hexagonal prisms. According to different arrangement modes, the porous aramid material can be divided into meta-aramid honeycomb and para-aramid honeycomb. The cell diameter and the thickness of the core material can be selected according to the size of the battery monomer and the heat management requirement. Further, the composite filler is filled in each honeycomb hole, and the composite filler is composed of a heat-conducting phase change capsule and a heat insulation material. The composite filler is a solid, which is easy to fill and adsorb and store in the honeycomb hole. By adjusting the type and proportion of the heat-conducting phase change capsule and the heat insulation material, the heat-conducting and heat-insulating performance of the heat dissipation and heat insulation composite material can be further optimized to meet the requirements of different application scenarios.

[0057] Example 1

[0058] Preparation of heat-conducting phase change microcapsule: 10 g of n-docosane was dissolved in 100 mL of formamide, and then 0.1 g of sodium dodecyl sulfate was added to the solution. The solution was stirred at 75°C and 600 rpm for 1 h to obtain a uniform and stable phase change emulsion. 37% hydrochloric acid was added dropwise to the reaction solution to adjust the pH value to 2.5. 10 g of tetrabutyl titanate was continuously added dropwise to the reaction solution, and the solution was stirred at 75°C and 750 rpm until it became gel-like. The solution was filtered with a vacuum pump to obtain gel precipitate, which was then washed with deionized water and anhydrous ethanol, and then left to dry for 24 hours. Finally, a titanium dioxide-coated n-docosane microcapsule solid powder was obtained, with a particle size of 50 μm and a wall thickness of 5 μm.

[0059] Preparation of honeycomb composite structure heat dissipation and heat insulation material: an aramid honeycomb plate with a size of 300 mm x 100 mm x 2 mm and a honeycomb diameter of 3 mm was selected. The hollow glass microsphere powder and the n-docosane microcapsule powder were uniformly mixed to form a composite filler, with a mass ratio of 3:2. The particle size of the hollow glass microsphere was 100 μm, the wall thickness was 2 μm, and the density was 0.4 g / cm 3 . According to the size of the battery monomer and the aramid honeycomb plate, the aluminum plastic film (thickness of 0.2 mm, 10 g) was cut to the required size. The lower surface of the aramid honeycomb plate was bonded to the aluminum plastic film at room temperature using structural adhesive, and the composite filler powder was filled into the honeycomb using a piston syringe. The mass ratio of the aramid honeycomb plate and the filler was 22:1. After filling, the upper surface of the honeycomb core material was bonded to the aluminum plastic film to obtain a honeycomb composite structure heat dissipation and heat insulation material with a size of 300.4 mm x 100.4 mm x 2.4 mm.

[0060] Example 2

[0061] Preparation of heat-conducting phase change microcapsules: 10 g of paraffin was dissolved in 100 mL of formamide, and 0.1 g of sodium dodecyl sulfate was added to the solution, which was stirred at 600 rpm at 75°C for 1 h to obtain a uniform and stable phase change emulsion. A 37% hydrochloric acid solution was added dropwise to the reaction solution to adjust the pH value to 2.5. 10 g of tetrabutyl titanate was continuously added dropwise to the reaction solution, which was stirred at 750 rpm at 75°C until a gel was formed. The solution was filtered with a vacuum pump to obtain a gel precipitate, which was washed with deionized water and anhydrous ethanol, and then left to dry for 24 hours. Finally, titanium dioxide-coated paraffin microcapsule solid powder was obtained, with a particle size of 50 μm and a wall thickness of 5 μm.

[0062] Preparation of honeycomb composite structure heat dissipation and heat resistance material: an aramid honeycomb plate with a size of 300 mm x 100 mm x 2 mm and a core aperture of 3 mm was selected. Hollow glass microsphere powder and paraffin microcapsule powder with a mass ratio of 3:2 were uniformly mixed to form a composite filler. The hollow glass microspheres had a particle size of 100 μm, a wall thickness of 2 μm, and a density of 0.4 g / cm 3 . According to the size of the battery monomer and the aramid honeycomb plate, an aluminum plastic film (thickness of 0.2 mm, 10 g) was cut to the required size. The lower surface of the aramid honeycomb plate was bonded to the aluminum plastic film at room temperature using a structural adhesive. A piston-type syringe was used to fill the composite filler powder into the honeycomb. The mass ratio of the aramid honeycomb plate to the filler was 22:1. After filling, the upper surface of the honeycomb core material was bonded to the aluminum plastic film to obtain a honeycomb composite structure heat dissipation and heat resistance material with a size of 300.4 mm x 100.4 mm x 2.4 mm.

[0063] Comparative Example 1

[0064] An aramid honeycomb plate with a size of 300 mm x 100 mm x 2 mm was selected. An aluminum plastic film (thickness of 0.2 mm, 10 g) was bonded to the upper surface of the aramid honeycomb plate without filling the composite filler.

[0065] Test Example

[0066] The thermal conductivity coefficients of the materials obtained in Examples 1-2 and Comparative Example 1 at 25°C, 60°C, and 100°C were tested using a thermal constant analyzer. The test results are shown in Table 1.

[0067] Table 1 Thermal conductivity coefficients of the materials obtained in Examples 1-2 and Comparative Example 1 at 25°C, 60°C, and 100°C

[0068]

[0069] As shown in Table 1, the honeycomb composite material has a high thermal conductivity at normal temperature, which ensures the heat dissipation performance of the power battery system at normal temperature; the thermal conductivity is 0.06 W / m*K after the 100 DEG C heat conduction phase change material is completely consumed, the heat insulation performance of the aramid honeycomb plate is improved, and the heat spread inhibition effect on the power battery system is better.

[0070] Although the above embodiment has made a detailed description of the present application, it is only a part of the embodiments of the present application, not all the embodiments, and other embodiments can be obtained according to the present embodiment without creativity, and these embodiments all belong to the protection scope of the present application.

Claims

1. A heat dissipation and heat-insulating composite material, characterized in that, Includes a heat-resistant material and an insulating film covering the surface of the heat-resistant material; The heat-insulating material includes a porous aramid material and a composite filler filling the pores of the porous aramid material; the mass ratio of the porous aramid material to the composite filler is 20-25:

1. The composite filler comprises 20-50% thermally conductive phase change capsules and 50-80% thermal insulation material by weight percentage; the thermal insulation material comprises one or more of hollow glass microspheres, ceramic nanofiber aerogels, and silica aerogels. The core material of the thermally conductive phase change capsule is a thermally conductive phase change material; the phase change temperature of the core material of the thermally conductive phase change capsule is 40-60℃; the wall material of the thermally conductive phase change capsule includes silicon dioxide and / or titanium dioxide.

2. The heat dissipation and heat-insulating composite material according to claim 1, characterized in that, The particle size of the thermal insulation material is 10–250 μm.

3. The heat dissipation and heat-insulating composite material according to claim 1, characterized in that, The particle size of the thermally conductive phase change capsule is 1–100 μm; the wall thickness of the thermally conductive phase change capsule is 0.01–10 μm.

4. The heat dissipation and heat-insulating composite material according to claim 3, characterized in that, In the preparation method of thermally conductive phase change capsules, the emulsifier includes anionic surfactant emulsifiers and / or nonionic surfactant emulsifiers; the mass of the emulsifier is 1-2% of the core material mass; The pH of the acidic conditions is 2 to 3; the mass ratio of the core material to the titanium source is 1:1 to 3.

5. The heat dissipation and heat-insulating composite material according to claim 1, characterized in that, The porous aramid material has a density of 0.03–0.2 g / cm³ and a thickness of 2–3 mm. The porous aramid material has pores that extend along its thickness direction; the pores are hexagonal prisms, square prisms, or cylinders; and the pore diameter is 1–4 mm.

6. The heat dissipation and heat-insulating composite material according to claim 1, characterized in that, The insulating film includes aluminum-plastic film, high-temperature nylon film, or polyimide film; the thickness of the insulating film is 0.075–0.25 mm.

7. The method for preparing the heat dissipation and heat-insulating composite material according to any one of claims 1 to 6, characterized in that, Includes the following steps: A composite filler is obtained by mixing a thermally conductive phase change capsule with a thermal insulation material; The composite filler is filled into the pores of a porous aramid material to obtain a heat-insulating material; The heat-insulating material is encapsulated with an insulating film to obtain the heat dissipation and heat-insulating composite material.

8. The application of the heat dissipation and heat-insulating composite material according to any one of claims 1 to 6 or the heat dissipation and heat-insulating composite material obtained by the preparation method according to claim 7 in a battery system.

9. A battery system, characterized in that, It includes alternating battery cells and heat-dissipating and heat-resistant composite materials; the heat-dissipating and heat-resistant composite material is the heat-dissipating and heat-resistant composite material according to any one of claims 1 to 6 or the heat-dissipating and heat-resistant composite material obtained by the preparation method of claim 7.

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