CN111187597A - Molten salt polymer composite phase change microcapsule heat storage material, preparation method thereof and lithium battery - Google Patents
Molten salt polymer composite phase change microcapsule heat storage material, preparation method thereof and lithium battery Download PDFInfo
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Abstract
The invention discloses a fused salt polymer composite phase change microcapsule heat storage material, which is a microcapsule bead formed by encapsulating a fused salt energy storage medium with a capsule core in a compact modified polyethylene glycol film layer; the capsule core molten salt energy storage medium comprises the following components in percentage by weight: 10-25 wt% of lithium nitrate, 10-25 wt% of sodium nitrate, 10-20 wt% of potassium nitrate, 10-20 wt% of calcium nitrate, 5-10 wt% of sodium nitrite, 5-10 wt% of potassium nitrite, 5-8 wt% of lithium chloride, 5-8 wt% of sodium chloride, 5-9 wt% of potassium chloride and 5-9 wt% of calcium chloride; the modified polyethylene glycol film layer is a solid-solid phase change energy storage material layer and is polystyrene/maleic anhydride cross-linked polyethylene glycol formed by electron beam irradiation. The invention also discloses a preparation method of the microcapsule heat storage material. The phase-change temperature of the heat storage material is close to 60 ℃, the fluidity and the corrosivity of the core material are prevented, the synergistic heat absorption and temperature control effects are exerted, the safety is higher, the capsule size is uniform, the surface is smooth and compact, and the preparation efficiency is high.
Description
Technical Field
The invention relates to the technical field of lithium battery heat storage materials, in particular to a molten salt polymer composite phase change microcapsule heat storage material, a preparation method thereof and a lithium battery.
Background
Nowadays, a clean energy automobile using a battery as power becomes the mainstream direction of automobile development, and at present, large-scale electric automobile companies at home and abroad all use a lithium battery as a power source of the electric automobile. The lithium battery can meet the power requirement of the electric automobile, but has the defects that the battery short circuit possibly occurs in the using process to cause a large amount of heat to accumulate and heat up, and the thermal safety accidents such as ignition and combustion, even explosion and the like are caused, for example: the main reason of the combustion and explosion accidents of the Tesla electric automobile is caused by heat accumulation of the lithium battery in the charging and discharging processes. If the heat generated in the use process of the lithium battery can be absorbed or transferred in time to maintain the battery in a proper temperature range (not exceeding 60 ℃), the thermal runaway of the lithium battery can be solved. The phase-change material can absorb and store a large amount of heat at a fixed temperature or in a narrow temperature range, and if the phase-change material is manufactured into a battery shell to coat a lithium battery, the heat of the lithium battery in the charging and discharging process can be well absorbed, so that the phase-change material is a potential method for solving the thermal runaway problem of the lithium battery.
Polyethylene glycol is a common high molecular phase change compound, has the advantages of no toxicity and harm, small phase change volume change, easy processing and forming and the like when the melting point is between 20 and 70 ℃, but has limited heat absorption and energy storage capacity because the phase change enthalpy is not large (the phase change enthalpy of the polyethylene glycol with the molecular weight between 2000 and 20000 is about 180 joules/gram), belongs to a solid-liquid phase change type, has the defect of easy leakage in the using process, and needs to be chemically modified to form a solid-solid phase change material. The chemical crosslinking/grafting method is the most commonly used method for preparing high molecular solid-solid phase change materials, but the method usually requires a specific chemical initiator, and requires reaction time of several hours or even tens of hours, and the reaction rate is slow. On the contrary, the electron beam irradiation technique can rapidly generate a large amount of active radicals in a short time, thereby completing the crosslinking/grafting reaction between materials in a short time, and simultaneously avoiding introducing new species into the reaction system. Inorganic molten salts and mixed salts thereof as phase change materials generally have large phase change enthalpy and specific heat capacity (for example, the phase change enthalpy of lithium nitrate is 373 joules/gram), but they belong to solid-liquid phase change and easily cause leakage problem in liquid state. The prior Chinese patents show that two mixed molten salt phase change energy storage materials such as ZL201510056451.1 and ZL201510056440.3 have melting points of more than 65 ℃, are used as phase change energy storage materials for thermal regulation of lithium batteries, and need further improvement on the formula and the melting point, and avoid a single solid-liquid phase change conversion type during the use process.
In view of the above, it is necessary to develop a temperature control material with a lower melting point, and an inorganic fused salt is used as a phase change core, and a polymer phase change material is used as a shell, so that the polymer material firmly coats the inorganic fused salt to form a microcapsule, thereby obtaining a bifunctional composite phase change capsule material, forming a microcapsule phase change material which fully combines the advantages of the fused salt phase change material and the solid polymer phase change material, and having a great application prospect in the field of power lithium batteries.
Disclosure of Invention
The invention aims to provide a fused salt polymer composite phase change microcapsule heat storage material, a preparation method thereof and a lithium battery aiming at the defects of the prior art, the microcapsule heat storage material is a phase-change core-shell microcapsule material for storing heat energy, both core and shell materials are phase change materials, the phase change temperature is close to 60 ℃, the fluidity and the corrosivity of the core material are prevented, the synergistic heat absorption and temperature control effects are exerted, the safety is higher, the capsule size is uniform, the surface is smooth and compact, and the preparation efficiency is high.
The technical scheme adopted by the invention to achieve the aim is as follows:
a fused salt polymer composite phase change microcapsule heat storage material is a microcapsule bead formed by encapsulating a capsule core fused salt energy storage medium in a compact modified polyethylene glycol film layer.
Preferably, the capsule core molten salt energy storage medium comprises the following components in percentage by weight: 10-25 wt% of lithium nitrate, 10-25 wt% of sodium nitrate, 10-20 wt% of potassium nitrate, 10-20 wt% of calcium nitrate, 5-10 wt% of sodium nitrite, 5-10 wt% of potassium nitrite, 5-8 wt% of lithium chloride, 5-8 wt% of sodium chloride, 5-9 wt% of potassium chloride and 5-9 wt% of calcium chloride; the components are mixed, heated and melted to prepare the energy storage medium.
Preferably, the modified polyethylene glycol film layer is a solid-solid phase change energy storage material layer and is polystyrene/maleic anhydride crosslinking modified polyethylene glycol formed by electron beam irradiation.
The capsule core fused salt energy storage medium is used as a core material and is encapsulated in a compact modified polyethylene glycol film layer, namely a solid-solid phase change energy storage material film layer of polystyrene/maleic anhydride cross-linked polyethylene glycol generated by electron beam irradiation, so as to form microcapsule pellets.
Preferably, the capsule core molten salt energy storage medium and the modified polyethylene glycol film layer are made of phase change materials, and the phase change points with the same temperature are close to 60 ℃.
A method for preparing a molten salt polymer composite phase change microcapsule heat storage material comprises the following steps:
s1: drying single-salt lithium nitrate, sodium nitrate, potassium nitrate, calcium nitrate, sodium nitrite, potassium nitrite, lithium chloride, sodium chloride, potassium chloride and calcium chloride, grinding into fine powder according to a certain proportion to obtain mixed salt, melting, stirring, cooling, grinding into mixed molten salt fine powder, and sieving by using a 100-mesh 200-mesh sieve;
s2: adding 80-120ml of mineral oil and 1-4ml of span 20 as a surfactant into a round-bottom flask, adding 2-6g of sieved mixed molten salt fine powder, and stirring and dispersing uniformly under heating to form emulsion;
s3: adding 20-50ml of isoamyl acetate solvent, 1-4g of maleic anhydride, 2-5g of styrene and 1-4g of polyethylene glycol with the average molecular weight of 4000 into another round-bottom flask, and heating, stirring, dispersing and uniformly mixing to obtain a prepolymer solution;
s4: and (4) fully mixing and uniformly stirring the emulsion obtained in the step S2 and the prepolymer solution obtained in the step S3, then filling the mixture into a plastic bag special for irradiation, and performing radiation polymerization reaction by using a high-energy electron beam as an irradiation source to obtain microcapsule pellets.
Preferably, the heating, stirring and dispersing temperature in the step S2 is 70-100 ℃, and the time is 1-3 hours.
Preferably, the heating, stirring and dispersing temperature in the step S3 is 70-100 ℃, and the time is 1-3 hours.
Preferably, the irradiation dose rate for the radiation polymerization reaction in the step S4 is 5-100 KGy/S.
A lithium battery is characterized in that the surface of the lithium battery is coated with a temperature control layer, and the temperature control layer is a thin shell or a grid made of the fused salt polymer composite phase change microcapsule heat storage material.
The action mechanism of the microcapsule heat storage material is as follows: a composition point exists in a system of an inner core material of lithium nitrate, sodium nitrate, potassium nitrate, calcium nitrate, sodium nitrite, potassium nitrite, lithium chloride, sodium chloride, potassium chloride and calcium chloride, and the phase transition temperature of the composition point is close to 60 ℃; the phase-change microcapsule is made into a thin shell or grid to cover the power lithium battery, when the temperature of the power lithium battery exceeds 60 ℃, the core and the shell phase-change energy storage material of the microcapsule simultaneously generate solid-liquid phase change to absorb a large amount of heat, so that the temperature of the lithium battery does not exceed 60 ℃ to obtain a stable safe state. The core and the shell of the novel microcapsule are made of phase-change materials and have phase-change points (both 60 ℃) with the same temperature, and the core and the shell of the microcapsule jointly play a role in synergistic heat absorption and temperature control, so that liquid leakage and corrosion of the core materials during solid-liquid phase change energy storage are well avoided, the unit heat absorption energy storage density of the phase-change materials is improved, and the comprehensive thermal property of the phase-change materials is improved.
Compared with the prior art, the invention has the following technical effects:
1. the invention relates to a novel internal and external composite phase change microcapsule energy storage material, wherein a capsule core is a mixed molten salt solid-liquid phase change material, the phase change temperature is 60 ℃, meanwhile, a microcapsule shell is a modified polyethylene glycol solid-solid phase change material, and a solid polymer shell prevents the flowability and corrosivity of the core material; the fused salt core phase-change material has the advantages of sharp phase-change temperature, large phase-change enthalpy value (much heat absorption and heat storage) and the like, the shell phase-change material has the phase-change temperature (60 ℃) consistent with that of the core phase-change material, and the shell material heat storage mode is solid-solid phase change, so that the problems of leakage and corrosion of the core material during solid-liquid phase change are well solved. The advantages of high phase change enthalpy and high heat conductivity coefficient of the molten salt are combined, the molten salt and the high phase change enthalpy and the high heat conductivity coefficient jointly play a synergistic heat absorption and temperature control role, and the solid-solid phase change advantages of the modified high polymer material are combined, so that the defects that the traditional solid-liquid phase change is easy to leak and the like are overcome.
2. When the temperature of the lithium battery is higher than 60 ℃, the internal and external double-function phase change microcapsule material can absorb a large amount of heat from the lithium battery through self melting and heat absorption to generate phase change, so that the lithium battery is maintained at a safe temperature, and the phase change microcapsule material has a wide market prospect in the aspect of being used as a temperature control material of the lithium battery of a power automobile.
3. Compared with the traditional pure chemical capsule synthesis method, the electron beam irradiation crosslinking experimental method adopted by the invention has the advantages of simplicity, rapidness, high efficiency, complete reaction conversion, no need of adding an external initiator, uniform capsule product size, smooth and compact surface and the like. The traditional chemical synthesis capsule method generally needs nitrogen protection, needs to add external initiator and always needs continuous reaction for more than ten hours at high temperature, so that the steps are complicated.
The foregoing is a summary of the technical solutions of the present invention, and the present invention is further described below with reference to the accompanying drawings and detailed description.
Drawings
FIG. 1 is a scanning electron microscope image of the surface microtopography of the present invention;
FIG. 2 is a DSC plot of a sample of the present invention; a represents modified polyethylene glycol; b represents mixed molten salt before irradiation; c represents microcapsules prepared by irradiation.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the following embodiments are described in detail. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Example 1: the heat storage material is a microcapsule bead formed by encapsulating a capsule core molten salt energy storage medium in a compact modified polyethylene glycol film layer. The capsule core molten salt energy storage medium comprises the following components in percentage by weight: 10 wt% lithium nitrate, 10 wt% sodium nitrate, 20 wt% potassium nitrate, 20 wt% calcium nitrate, 5 wt% sodium nitrite, 5 wt% potassium nitrite, 6 wt% lithium chloride, 6 wt% sodium chloride, 9 wt% potassium chloride, 9 wt% calcium chloride; the components are mixed, heated and melted to prepare the energy storage medium. The modified polyethylene glycol film layer is a solid-solid phase change energy storage material layer and is polystyrene/maleic anhydride crosslinking modified polyethylene glycol formed by electron beam irradiation. The capsule core fused salt energy storage medium is used as a core material and is encapsulated in a compact modified polyethylene glycol film layer, namely a solid-solid phase change energy storage material film layer of polystyrene/maleic anhydride cross-linked polyethylene glycol generated by electron beam irradiation, so as to form microcapsule pellets. The capsule core molten salt energy storage medium and the modified polyethylene glycol film layer are made of phase change materials, and the phase change points with the same temperature are close to 60 ℃. The embodiment also provides a lithium battery, wherein the surface of the lithium battery is coated with a temperature control layer, and the temperature control layer is a thin shell or a grid made of the fused salt polymer composite phase change microcapsule heat storage material.
The embodiment also provides a preparation method of the molten salt polymer composite phase change microcapsule heat storage material, which comprises the following steps:
s1: drying single salt lithium nitrate, sodium nitrate, potassium nitrate, calcium nitrate, sodium nitrite, potassium nitrite, lithium chloride, sodium chloride, potassium chloride and calcium chloride, grinding into fine powder according to a certain proportion to obtain mixed salt, wherein the melting point is close to 60 ℃, the mixed salt is subjected to heat preservation melting at 100 ℃, stirring and cooling, then ground into mixed molten salt fine powder, and sieved by a 100-mesh 200-mesh sieve.
S2: adding 80ml of mineral oil and 4ml of surfactant span 20 into a round-bottom flask, adding 2g of sieved mixed molten salt fine powder, and stirring and dispersing uniformly under a heating condition to form emulsion; the temperature for heating, stirring and dispersing is 70 ℃, and the time is 3 hours.
S3: adding 20ml of isoamyl acetate solvent, 4g of maleic anhydride, 2g of styrene and 4g of polyethylene glycol with the average molecular weight of 4000 into another round-bottom flask, heating, stirring, dispersing and uniformly mixing to obtain a prepolymer solution; the temperature for heating, stirring and dispersing is 100 ℃, and the time is 1 hour.
S4: fully mixing and uniformly stirring the emulsion obtained in the step S2 and the prepolymer solution obtained in the step S3, then filling the mixture into a plastic bag special for irradiation, and performing radiation polymerization reaction by using a high-energy electron beam as an irradiation source to obtain microcapsule balls; forming a mixed solution with the thickness of 1-2 mm in a plastic bag special for irradiation, and performing irradiation polymerization reaction on the interface of the suspended liquid molten salt micro-particles, wherein the irradiation dose rate adopted by the irradiation polymerization reaction is 5-100 KGy/s. The modified polyethylene glycol generated on the surface of the molten salt liquid drop is actually polystyrene/maleic anhydride cross-linked polyethylene glycol generated by electron beam irradiation, and is a solid-solid phase change energy storage material.
And finally, filtering and washing the obtained microcapsule pellets by adopting cyclohexane, and drying in vacuum at the temperature of 30 ℃ to obtain a microcapsule product. The method has the advantages of obvious advantages, no need of chemical initiator, high preparation efficiency, uniform capsule size and smooth and compact surface.
Example 2: the embodiment provides a molten salt polymer composite phase change microcapsule heat storage material, a preparation method thereof and a lithium battery, which are basically the same as the embodiments 1 and 2, and have the following differences: the capsule core molten salt energy storage medium comprises the following components in percentage by weight: 25 wt% of lithium nitrate, 25 wt% of sodium nitrate, 10 wt% of potassium nitrate, 10 wt% of calcium nitrate, 5 wt% of sodium nitrite, 5 wt% of potassium nitrite, 5 wt% of lithium chloride, 5 wt% of sodium chloride, 5 wt% of potassium chloride and 5 wt% of calcium chloride. The preparation method comprises the following steps: s2: adding 120ml of mineral oil and 1ml of span 20 as a surfactant into a round-bottom flask, adding 6g of sieved mixed molten salt fine powder, and stirring and dispersing uniformly under a heating condition to form emulsion; the temperature for heating, stirring and dispersing is 100 ℃, and the time is 1 hour. S3: adding 50ml of isoamyl acetate solvent, 1g of maleic anhydride, 5g of styrene and 1g of polyethylene glycol with the average molecular weight of 4000 into another round-bottom flask, heating, stirring, dispersing and uniformly mixing to obtain a prepolymer solution; the temperature for heating, stirring and dispersing is 70 ℃, and the time is 3 hours.
Example 3: the molten salt polymer composite phase change microcapsule heat storage material and the preparation method thereof and the lithium battery provided by the embodiment are basically the same as the embodiments 1 and 2, and the difference is that: the capsule core molten salt energy storage medium comprises the following components in percentage by weight: 12 wt% lithium nitrate, 13 wt% sodium nitrate, 17 wt% potassium nitrate, 18 wt% calcium nitrate, 7 wt% sodium nitrite, 7 wt% potassium nitrite, 8 wt% lithium chloride, 8 wt% sodium chloride, 5 wt% potassium chloride, 5 wt% calcium chloride. The preparation method comprises the following steps: s2: adding 100ml of mineral oil and 4ml of surfactant span 20 into a round-bottom flask, adding 3g of sieved mixed molten salt fine powder, and stirring and dispersing uniformly under a heating condition to form emulsion; the temperature for heating, stirring and dispersing is 80 ℃, and the time is 2 hours. S3: adding 45ml of isoamyl acetate solvent, 3g of maleic anhydride, 4g of styrene and 3g of polyethylene glycol with the average molecular weight of 4000 into another round-bottom flask, heating, stirring, dispersing and uniformly mixing to obtain a prepolymer solution; the temperature for heating, stirring and dispersing is 70 ℃ and the time is 2 hours.
Example 4: the molten salt polymer composite phase change microcapsule heat storage material and the preparation method thereof and the lithium battery provided by the embodiment are basically the same as the embodiments 1 and 2, and the difference is that: the capsule core molten salt energy storage medium comprises the following components in percentage by weight: 15 wt% of lithium nitrate, 15 wt% of sodium nitrate, 15 wt% of potassium nitrate, 15 wt% of calcium nitrate, 8 wt% of sodium nitrite, 9 wt% of potassium nitrite, 7 wt% of lithium chloride, 6 wt% of sodium chloride, 5 wt% of potassium chloride and 5 wt% of calcium chloride. The preparation method comprises the following steps: s2: adding 100ml of mineral oil and 2ml of surfactant span 20 into a round-bottom flask, adding 5g of sieved mixed molten salt fine powder, and stirring and dispersing uniformly under a heating condition to form emulsion; the temperature for heating, stirring and dispersing is 90 ℃ and the time is 2 hours. S3: adding 40ml of isoamyl acetate solvent, 3g of maleic anhydride, 4g of styrene and 3g of polyethylene glycol with the average molecular weight of 4000 into another round-bottom flask, heating, stirring, dispersing and uniformly mixing to obtain a prepolymer solution; the temperature for heating, stirring and dispersing is 90 ℃ and the time is 2 hours.
Example 5: the molten salt polymer composite phase change microcapsule heat storage material and the preparation method thereof and the lithium battery provided by the embodiment are basically the same as the embodiments 1 and 2, and the difference is that: the capsule core molten salt energy storage medium comprises the following components in percentage by weight: 17 wt% lithium nitrate, 18 wt% sodium nitrate, 12 wt% potassium nitrate, 13 wt% calcium nitrate, 10 wt% sodium nitrite, 10 wt% potassium nitrite, 5 wt% lithium chloride, 5 wt% sodium chloride, 5 wt% potassium chloride, 5 wt% calcium chloride. The preparation method comprises the following steps: s2: adding 80ml of mineral oil and 3ml of span 20 as a surfactant into a round-bottom flask, adding 6g of sieved mixed molten salt fine powder, and stirring and dispersing uniformly under a heating condition to form emulsion; the temperature for heating, stirring and dispersing is 80 ℃, and the time is 2 hours. S3: adding 50ml of isoamyl acetate solvent, 2g of maleic anhydride, 3g of styrene and 4g of polyethylene glycol with the average molecular weight of 4000 into another round-bottom flask, heating, stirring, dispersing and uniformly mixing to obtain a prepolymer solution; the temperature for heating, stirring and dispersing is 80 ℃, and the time is 2 hours.
The microcapsule phase-change heat storage material is subjected to performance test, and a scanning electron microscope image of the surface micro-morphology of the microcapsule product is shown in figure 1, so that the microcapsule product has the advantages of consistent size, smooth surface and the like, the average size of the microcapsule product is about 150 micrometers, and the heat absorption and heat storage performance is the most core evaluation index of the phase-change microcapsule. The endothermic heat storage performance during heating can be well embodied by using a Differential Scanning Calorimetry (DSC) curve. And (3) carrying out DSC experimental test on the modified polyethylene glycol, the mixed molten salt and the microcapsule, wherein nitrogen atmosphere is adopted in the experimental test, and the heating rate is 5 ℃/min. As shown in fig. 2, three DSC curves, a, b, and c, respectively represent three samples, namely, modified polyethylene glycol, mixed molten salt before irradiation, and a microcapsule product, it can be seen that the phase transition melting point temperatures of the three samples are all very close to 60 ℃, and a in the curves is a high molecular material, and the phase transition enthalpy (the area of the endothermic peak) is the minimum; b in the curve is a molten salt material, and the phase change enthalpy of the molten salt material is maximum; in the curve c, the microcapsule prepared by compounding the two materials has phase change enthalpy between the samples a and b, and the fact that the microcapsule product is really combined with the matching of the phase change enthalpy of the high polymer material and the molten salt material is also verified.
Variations and modifications to the above-described embodiments may occur to those skilled in the art, which fall within the scope and spirit of the above description. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention.
Claims (9)
1. The heat storage material is a microcapsule ball formed by encapsulating a capsule core molten salt energy storage medium in a compact modified polyethylene glycol film layer.
2. The molten salt polymer composite phase change microcapsule heat storage material as claimed in claim 1, wherein the capsule core molten salt energy storage medium comprises the following components in percentage by weight: 10-25 wt% of lithium nitrate, 10-25 wt% of sodium nitrate, 10-20 wt% of potassium nitrate, 10-20 wt% of calcium nitrate, 5-10 wt% of sodium nitrite, 5-10 wt% of potassium nitrite, 5-8 wt% of lithium chloride, 5-8 wt% of sodium chloride, 5-9 wt% of potassium chloride and 5-9 wt% of calcium chloride.
3. The molten salt polymer composite phase change microcapsule heat storage material of claim 1, wherein the modified polyethylene glycol film layer is a solid-solid phase change energy storage material layer and is polystyrene/maleic anhydride cross-linked modified polyethylene glycol formed by electron beam irradiation.
4. The molten salt polymer composite phase change microcapsule heat storage material as claimed in claim 1, wherein the molten salt energy storage medium of the capsule core and the modified polyethylene glycol film layer are both made of phase change materials, and the phase change points with the same temperature are both close to 60 ℃.
5. A method for preparing a molten salt polymer composite phase change microcapsule heat storage material is characterized by comprising the following steps:
s1: drying single-salt lithium nitrate, sodium nitrate, potassium nitrate, calcium nitrate, sodium nitrite, potassium nitrite, lithium chloride, sodium chloride, potassium chloride and calcium chloride, grinding into fine powder according to a certain proportion to obtain mixed salt, melting, stirring, cooling, grinding into mixed molten salt fine powder, and sieving by using a 100-mesh 200-mesh sieve;
s2: adding 80-120ml of mineral oil and 1-4ml of span 20 as a surfactant into a round-bottom flask, adding 2-6g of sieved mixed molten salt fine powder, and stirring and dispersing uniformly under heating to form emulsion;
s3: adding 20-50ml of isoamyl acetate solvent, 1-4g of maleic anhydride, 2-5g of styrene and 1-4g of polyethylene glycol with the average molecular weight of 4000 into another round-bottom flask, and heating, stirring, dispersing and uniformly mixing to obtain a prepolymer solution;
s4: and (4) fully mixing and uniformly stirring the emulsion obtained in the step S2 and the prepolymer solution obtained in the step S3, then filling the mixture into a plastic bag special for irradiation, and performing radiation polymerization reaction by using a high-energy electron beam as an irradiation source to obtain microcapsule pellets.
6. The method for preparing a molten salt polymer composite phase change microcapsule heat storage material as claimed in claim 5, wherein the temperature for heating, stirring and dispersing in step S2 is 70-100 ℃, and the time is 1-3 hours.
7. The method for preparing a molten salt polymer composite phase change microcapsule heat storage material as claimed in claim 5, wherein the temperature for heating, stirring and dispersing in step S3 is 70-100 ℃, and the time is 1-3 hours.
8. The method for preparing a fused salt polymer composite phase change microcapsule heat storage material as claimed in claim 5, wherein the irradiation dose rate adopted by the radiation polymerization reaction in the step S4 is 5-100 KGy/S.
9. A lithium battery, characterized in that the surface of the lithium battery is coated with a temperature control layer, and the temperature control layer is a thin shell or a grid made of the fused salt polymer composite phase change microcapsule heat storage material of claims 1 to 4.
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| US20220363144A1 (en) * | 2021-05-17 | 2022-11-17 | Ford Global Technologies, Llc | Traction battery pack thermal management assembly |
| CN115558472A (en) * | 2022-11-05 | 2023-01-03 | 北京民利储能技术有限公司 | Heat transfer and energy storage molten salt material and preparation method thereof |
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| CN104559942A (en) * | 2015-02-03 | 2015-04-29 | 王军涛 | Mixed molten salt heat storage and heat transfer material and preparation method thereof |
| CN107779173A (en) * | 2017-10-12 | 2018-03-09 | 北京宇田相变储能科技有限公司 | A kind of microcapsules for improving thermal storage performance and combinations thereof formed body |
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| US11772500B2 (en) * | 2021-05-17 | 2023-10-03 | Ford Global Technologies, Llc | Traction battery pack thermal management assembly |
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