Preparation method for and use of polyurethane solid-solid phase change material

Abstract

Provided in the present application are a preparation method for and the use of a polyurethane solid-solid phase change material. The polyurethane solid-solid phase change material comprises a polymer skeleton and functional particles filled in the polymer skeleton, wherein the polymer skeleton comprises a first structure derived from polyethylene glycol and a second structure of an isocyanate compound, and the functional particles comprise an Fe3O4 inner core and a PZS shell layer coating at least part of the surface of the Fe3O4 inner core. The polyurethane solid-solid phase change material has good thermal stability and thermal conductivity, and a battery comprising the polyurethane solid-solid phase change material has good thermal management capability.

Description

Preparation method and application of a polyurethane solid-solid phase change material

[0001] The present application claims priority to the Chinese patent application No. 202411303290.7 filed on September 18, 2024, and entitled "Preparation method and application of a polyurethane solid-solid phase change material", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to a solid-solid phase change material, in particular to a preparation method and application of a polyurethane solid-solid phase change material, belonging to the technical field of electrochemical energy storage. BACKGROUND

[0003] Lithium ion batteries have the advantages of large capacity, high energy density, long cycle life, etc. However, if the battery temperature is too high, it will cause the battery life to be shortened, the internal structure to be damaged, and even the thermal runaway phenomenon to occur. If the battery temperature is too low, it will cause the internal resistance to increase, the capacity to decay, and the charging and discharging efficiency to decrease, etc., which hinders the improvement of battery efficiency for industries such as energy storage power stations, new energy vehicles, mobile power sources, and communication base stations. Therefore, a qualified and feasible battery thermal management technology is crucial for reducing the impact of environmental temperature on the battery and improving the battery energy conversion efficiency.

[0004] The phase change material thermal management system is a passive thermal management system with the advantages of simple design and high reliability. After the temperature rises, it maintains the battery temperature by melting and absorbing heat, maintains the battery temperature within a suitable range, balances the temperature difference between each part of the battery, thereby prolonging the service life of the battery, and the entire process does not require additional energy supply.

[0005] Phase change materials can be divided into three categories: organic, inorganic, and composite, according to the material composition. Among them, organic phase change materials have attracted widespread attention due to their good chemical stability, high energy storage density, and low supercooling characteristics. However, as the most commonly used phase change material, organic solid-liquid phase change materials are prone to leakage after absorbing heat, which poses a great threat to the stability, safety, and service life of the phase change material thermal management system. In addition, the rigidity of organic solid-liquid phase change materials and composite phase change materials cannot meet the needs of flexible electronic devices. Solid-solid phase change materials can fundamentally solve the leakage problem and have higher rigidity, but their thermal conductivity is relatively small, and their heat transfer ability is poor, which restricts their large-scale application. Therefore, it is of great significance to develop a solid-solid phase change material with good thermal stability and high thermal conductivity for improving the thermal management capability of lithium ion batteries. SUMMARY

[0006] In view of the above defects, the present application provides a polyurethane solid-solid phase change material, which has good thermal stability and high thermal conductivity, can improve the battery thermal management capability, and thus improve the battery efficiency.

[0007] The application provides a preparation method of a polyurethane solid-solid phase change material, which is simple in process and free of excess by-products in a synthesis process, and is favorable for large-scale application.

[0008] The application provides a thermal management component including the polyurethane solid-solid phase change material, which has good thermal stability and good heat conduction effect, and is favorable for improving the thermal management capability of a battery.

[0009] The application also provides a battery including the thermal management component, which has good thermal management capability.

[0010] An aspect of the application provides a polyurethane solid-solid phase change material including a polymer skeleton and functional particles filled in the polymer skeleton.

[0011] The polymer skeleton includes a first structure from polyethylene glycol and a second structure of an isocyanate compound, and the functional particles include an Fe3O4 core and a PZS shell layer covering at least part of the surface of the Fe3O4 core.

[0012] The polyurethane solid-solid phase change material as described above, wherein the mass ratio of the functional particles to the polymer skeleton is (0.002-0.09):1.

[0013] The polyurethane solid-solid phase change material as described above, wherein the mass ratio of the second structure to the first structure in the polymer skeleton is (0.01-0.2):1.

[0014] The polyurethane solid-solid phase change material as described above, wherein the mass ratio of the Fe3O4 core in the functional particles to the functional particles is 20-80%.

[0015] The polyurethane solid-solid phase change material as described above, wherein the isocyanate compound includes at least one of diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and naphthalene diisocyanate.

[0016] The polyurethane solid-solid phase change material as described above, wherein the polyurethane solid-solid phase change material is prepared by a method including the following process: adding polyethylene glycol to a dispersion liquid including an isocyanate compound and functional particles, initiating a polymerization reaction to obtain the polyurethane solid-solid phase change material; wherein the mass ratio of the isocyanate compound to the polyethylene glycol is (0.01-0.25):1; and the mass ratio of the functional particles to the total mass of the polyethylene glycol and the isocyanate compound is (0.005-0.1):1.

[0017] The polyurethane solid-solid phase change material as described above, wherein the functional particles are prepared by a method comprising the following process: mixing Fe3O4, an alkaline catalyst, a compound with a molecular formula of (N3P3) n Cl m reacting to obtain the functional particles, wherein n is a positive number, m = 1 or 2; the mass percentage of Fe3O4 in the functional particles is 20-80%.

[0018] The application further provides a preparation method of the polyurethane solid-solid phase change material, comprising the following steps:

[0019] 1) dispersing an isocyanate compound and functional particles in an organic solvent under an inert atmosphere to obtain a dispersion liquid;

[0020] 2) adding polyethylene glycol to the dispersion liquid under an inert atmosphere, and performing a polymerization reaction after adding a catalyst dropwise to obtain the polyurethane solid-solid phase change material.

[0021] The preparation method of the polyurethane solid-solid phase change material as described above, wherein in step 1), the organic solvent comprises at least one of anhydrous ethanol, tetrahydrofuran, ethyl acetate, acetonitrile, dichloromethane, chloroform, dimethylformamide, and polybutylene succinate diol; and / or,

[0022] the volume of the organic solvent to the mass of the solute is 2-4 L / g; and / or,

[0023] the dispersion time is 0.5-3 h, and the dispersion temperature is 30-80°C.

[0024] the reaction time of the polymerization reaction is 0.5-9 h, and the reaction temperature is 30-80°C; and / or,

[0025] the catalyst comprises at least one of dibutyltin dilaurate, stannous octoate, and zinc octoate; and / or,

[0026] the mass ratio of the catalyst to the polyethylene glycol is (0.001-0.02):1.

[0027] The application further provides a thermal management component comprising the polyurethane solid-solid phase change material as described above or prepared by the preparation method as described above.

[0028] The application further provides a battery comprising the polyurethane solid-solid phase change material as described above or the thermal management component as described above.

[0029] The polyurethane solid-solid phase change material provided by the application comprises a polymer skeleton and functional particles filled in the polymer skeleton. The polymer skeleton has a rigid hexamethylene skeleton, a benzene ring and hydrogen bonds, which can prevent the polyethylene glycol phase from leaking during the phase change process under heat; by adding functional particles in the polymer skeleton, the polyurethane solid-solid phase change material has good thermal stability and good thermal conductivity, thereby enabling the battery to have good thermal management capability. BRIEF DESCRIPTION OF DRAWINGS

[0030] Fig. 1 is a structural schematic diagram of the polyurethane solid-solid phase change material provided by the application. DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions and advantages of the application clearer, the technical solutions in the embodiments of the application will be described clearly and completely below with reference to the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without any creative work fall within the scope of protection of the application.

[0032] The first aspect of the application provides a polyurethane solid-solid phase change material, which comprises a polymer skeleton and functional particles filled in the polymer skeleton.

[0033] The polymer skeleton comprises a first structure from polyethylene glycol and a second structure of isocyanate compounds, and the functional particles comprise an Fe3O4 core and a PZS shell layer covering at least part of the surface of the Fe3O4 core.

[0034] The application does not limit the polymerization degree of polyethylene glycol, as long as it can react with isocyanate compounds. For example, the Mn of polyethylene glycol used for reaction is 200-10000.

[0035] The application also does not limit the type of Fe3O4, as long as it can form functional particles. In detail, it can be at least one of unmodified Fe3O4, hydroxylated Fe3O4, aminated Fe3O4 and carboxylated Fe3O4.

[0036] The Fe3O4 core in the application is fully or partially wrapped in the PZS shell layer to form functionalized particles, and the functionalized particles are filled in the polymer skeleton.

[0037] The polyethylene glycol and the isocyanate compound are cross-linked and polymerized to form a polymer skeleton, and the functional particles are filled in the polymer skeleton, so that the polyurethane solid-solid phase change material has good thermal stability and thermal conductivity. The applicant speculates that the reason may be that, on the one hand, the rigid group hexamethylene structure in the isocyanate compound and the hydrogen bond between the polymer segments can prevent the leakage of the polyethylene glycol phase during the phase change process, and maintain the thermal stability of the polyurethane solid-solid phase change material during the phase change process. On the other hand, the compound with the molecular formula (N3P3) n Cl m The compound with the molecular formula (N3P3) and the diphenol compound form a stable copolymer cyclotriphosphazene-co-4,4'-sulfonyldiphenol with a network structure, that is, a PZS shell. The benzene ring structure in the PZS shell can improve the thermal stability of the material, and the introduction of the cyclotriphosphazene group can endow the material with flame retardant properties. By combining the PZS shell with Fe3O4, a functional particle Fe3O4@PZS with good performance can be formed. The Fe3O4@PZS functional particle has excellent thermal conductivity, and when added to the polyurethane solid-solid phase change material, it can greatly improve the thermal conductivity of the material, and also endow the polyurethane solid-solid phase change material with flame retardant properties.

[0038] As shown in FIG. 1, by forming a polymer network with polyethylene glycol (PEG) and isocyanate compounds and embedding the functional particle Fe3O4@PZS in the constructed polymer network structure, the polyurethane solid-solid phase change material can have good shape stability, thermal stability and cycle stability.

[0039] In a specific embodiment, the mass ratio of the functional particle and the polymer skeleton is (0.002-0.09):1, for example, the mass ratio includes but is not limited to 0.002:1, 0.01:1, 0.03:1, 0.05:1, 0.07:1, 0.09:1 or a range composed of any two of them. By limiting the mass ratio of the polymer skeleton and the functional particle within this range, it is beneficial to form a polyurethane solid-solid phase change material with good thermal stability and thermal conductivity.

[0040] In a specific embodiment, the mass ratio of the second structure and the first structure is (0.01-0.2):1, for example, the mass ratio includes but is not limited to 0.01:1, 0.05:1, 0.10:1, 0.15:1, 0.20:1 or a range composed of any two of them. By limiting the mass ratio of the first structure and the second structure within this range, it is beneficial to construct a polymer scaffold with good performance, and then form a polyurethane solid-solid phase change material with good thermal stability and thermal conductivity.

[0041] In an embodiment, the mass percentage of the Fe3O4 core in the functional particle is 20-80%, for example, but not limited to, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or a range defined by any two of the above. By limiting the mass percentage of the Fe3O4 core in the functional particle to this range, it is beneficial to form a functional particle with good performance, thereby improving the thermal stability and thermal conductivity of the polymer skeleton.

[0042] In an embodiment, the isocyanate compound can be at least one of diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and naphthalene diisocyanate. The use of the above isocyanate compound can provide a rigid group hexamethylene structure that can make the polymer skeleton have good thermal stability during phase change.

[0043] The present application does not limit the molecular weight of the isocyanate compound involved in the reaction, and the isocyanate compound can be involved in the reaction in the form of a monomer or a polymer. For example, hexamethylene diisocyanate monomer with a molecular weight of Mn=168 can be used to participate in the reaction, or hexamethylene diisocyanate trimer with a molecular weight of Mn=348 can be used to participate in the reaction.

[0044] In an embodiment, the polyurethane solid-solid phase change material is prepared by a method comprising the following steps: adding polyethylene glycol to a dispersion liquid comprising an isocyanate compound and functional particles, initiating a polymerization reaction to obtain the polyurethane solid-solid phase change material.

[0045] The present application does not limit the dispersion method of the isocyanate compound and the functional particles, as long as it can be uniformly dispersed, such as using stirring to disperse the isocyanate compound and the functional particles.

[0046] The present application also does not limit the method of adding polyethylene glycol to the dispersion liquid comprising the isocyanate compound and the functional particles. For example, the polyethylene glycol can be added to the dispersion liquid comprising the isocyanate compound and the functional particles and stirred uniformly, or the dispersion liquid of the isocyanate compound and the functional particles can be added to the polyethylene glycol and stirred uniformly. In addition, the above solutes can also be uniformly dispersed by using ultrasonic method.

[0047] In an embodiment, the mass ratio of the isocyanate compound to the polyethylene glycol is (0.01-0.25):1, for example, but not limited to, 0.01:1, 0.05:1, 0.10:1, 0.15:1, 0.20:1, 0.25:1, or a range defined by any two of the above.

[0048] In another embodiment, the mass ratio of the functional particle to the total mass of the polyethylene glycol and the isocyanate compound is (0.005-0.1):1, for example, the mass ratio includes but is not limited to 0.005:1, 0.01:1, 0.03:1, 0.05:1, 0.08:1, 0.10:1, or a range consisting of any two of them.

[0049] In one embodiment, the functional particle is prepared by a method comprising the following process: mixing Fe3O4, a basic catalyst, a compound of formula (N3P3) n Cl m , a diphenol compound, and a solvent, and reacting to obtain the functional particle, wherein n is a positive number, m = 1 or 2,

[0050] In one embodiment, the mass fraction of Fe3O4 in the functional particle is 20-80%. For example, the mass fraction of Fe3O4 in the functional particle includes but is not limited to 20%, 30%, 40%, 50%, 60%, 70%, 80%, or a range consisting of any two of them.

[0051] The application does not limit the type of basic catalyst, as long as it can accelerate the reaction rate of the compound of formula (N3P3) n Cl m , and the diphenol compound, for example, the basic catalyst can be at least one of triethylamine, dimethylcyclohexylamine, trimethylamine, and triethanolamine. By adding a basic catalyst, the chloride ions produced during the reaction of the compound of formula (N3P3) n Cl m and the diphenol compound can be consumed, thereby accelerating the generation of the functional particle.

[0052] The compound of formula (N3P3) n Cl m in the application contains alternating phosphorus and nitrogen atoms, and the alternating phosphorus and nitrogen atoms form a six-membered ring structure, and each phosphorus atom is connected to one or two chlorine atoms. The compound of formula (N3P3) n Cl m may have only one phosphorus and nitrogen atom forming a six-membered ring structure, or n phosphorus and nitrogen atoms forming a six-membered ring structure. For example, the compound of formula (N3P3) n Cl mThe compounds can be at least one of hexachlorocyclotriphosphazene and hexachlorocyclophosphazene. Because these compounds contain a large number of chlorine atoms, they exhibit good thermal stability and typically have high melting points. Using these chemicals to generate functional particles can impart good thermal stability to the functional particles.

[0053] This application does not limit the types of diphenol compounds, as long as they can be combined with compounds of the molecular formula (N3P3). n Cl m The reaction can occur by reacting with the compounds. For example, the diphenolic compounds can be at least one of 4,4-dihydroxydiphenol and hydroquinone bissulfonamide. By using the above-mentioned diphenolic compounds for the reaction, a stable benzene ring structure can be introduced, thereby improving the thermal stability of the functional particles.

[0054] This application is not limited to Fe3O4, alkaline catalysts, or molecules with the formula (N3P3). n Cl m The method of mixing compounds, diphenols, and solvents is as long as the above components can be mixed evenly. For example, the above components can be mixed evenly by ultrasound or by stirring.

[0055] This application does not limit the reaction time and reaction temperature for the preparation of functional particles, as long as the purpose of generating functional particles can be achieved. For example, the reaction time can be 3 to 6 hours and the reaction temperature can be 30 to 80°C.

[0056] This application does not limit the method for separating and purifying functional particles, as long as the separation and purification purpose can be achieved. For example, functional particles can be separated and purified by centrifugation, or by magnetic separation using a magnet. By using the above separation and purification methods, functional particles with high purity can be obtained for the preparation of polyurethane solid-solid phase change materials, thereby improving the thermal stability and thermal conductivity of polyurethane solid-solid phase change materials.

[0057] A second aspect of this application provides a method for preparing a polyurethane solid-solid phase change material, the method comprising the following steps:

[0058] 1) Under an inert atmosphere, isocyanate compounds and functional particles are dispersed in an organic solvent to obtain a dispersion;

[0059] 2) Under an inert atmosphere, polyethylene glycol is added to the dispersion, and a catalyst is added dropwise to carry out a polymerization reaction to obtain the polyurethane solid-solid phase change material.

[0060] In the preparation method, the mass ratio of the isocyanate compound to the polyethylene glycol can be (0.01-0.25):1. By controlling the mass ratio of the isocyanate compound to the polyethylene glycol in the above range, the polyurethane solid-solid phase change material with the mass ratio of the second structure to the first structure being (0.01-0.2):1 can be obtained.

[0061] In the preparation method, the mass ratio of the functional particles to the total mass of the polyethylene glycol and the isocyanate compound can be (0.005-0.1):1. By controlling the mass ratio of the functional particles to the total mass of the polyethylene glycol and the isocyanate compound in the above range, the polyurethane solid-solid phase change material with the mass ratio of the functional particles to the polymer skeleton being (0.002-0.09):1 can be obtained.

[0062] In the preparation method, the mass percentage of Fe3O4 in the functional particles can be 20-80%. By controlling the mass percentage of Fe3O4 in the functional particles in the above range, the polyurethane solid-solid phase change material with the mass percentage of the Fe3O4 core in the functional particles being 20-80% can be obtained.

[0063] The present application does not limit the type of inert atmosphere, as long as it does not react with the components in the reaction system. For example, the inert atmosphere can be nitrogen, argon, helium and other gases that are not easy to react. Using these gases as an inert atmosphere can protect the sample or reaction from the environment of active ingredients.

[0064] The present application also does not limit the dispersion method, time and temperature, as long as the isocyanate compound and the functional particles can be uniformly dispersed. For example, the isocyanate compound can be added to the organic solvent containing the functional particles and stirred at 30-80°C for 0.5-3h. Alternatively, the functional particles can be added to the organic solvent containing the isocyanate compound and stirred at 30-80°C for 0.5-3h. The system of isocyanate compound, functional particles and organic solvent can also be dispersed by ultrasonic method. A uniformly dispersed system is conducive to the formation of polyurethane solid-solid phase change material with good performance.

[0065] In a specific embodiment, the reaction solution of the polymerization is first dried at 60°C for 6-12h and then dried at 80°C for 6-12h to obtain the polyurethane solid-solid phase change material. For example, the drying time includes but is not limited to 6h, 8h, 10h, 12h or a range formed by any two of them. Through the above two-step drying operation, the solvent in the polyurethane solid-solid phase change material can be volatilized, and the polyurethane solid-solid phase change material can be plasticized in the process to prepare different forms of polyurethane solid-solid phase change material for actual use.

[0066] In an embodiment, the organic solvent includes at least one of anhydrous ethanol, tetrahydrofuran, ethyl acetate, acetonitrile, dichloromethane, chloroform, dimethylformamide, polybutylene succinate glycol. The use of the above organic solvents can make the solute uniformly dispersed, thereby facilitating the preparation of the polyurethane solid-solid phase change material with good performance.

[0067] In another embodiment, the volume-to-mass ratio of the organic solvent to the solute is 2-4 L / g. For example, the volume-to-mass ratio of the organic solvent to the solute includes, but is not limited to, 2 L / g, 2.5 L / g, 3 L / g, 3.5 L / g, 4 L / g, or a range formed by any two of them. The solute includes isocyanate compounds, functional particles, and polyethylene glycol. By controlling the volume-to-mass ratio of the organic solvent to the solute in the above range, the solute can be uniformly dispersed, thereby facilitating the preparation of the polyurethane solid-solid phase change material with good performance.

[0068] In another embodiment, the dispersion time is 0.5-3 h, and the dispersion temperature is 30-80℃. For example, the dispersion time includes, but is not limited to, 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, or a range formed by any two of them; the dispersion temperature includes, but is not limited to, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, or a range formed by any two of them. By controlling the dispersion time and the dispersion temperature in the above range, the solute can be uniformly dispersed, thereby facilitating the preparation of the polyurethane solid-solid phase change material with good performance.

[0069] In another embodiment, the reaction time of the polymerization reaction is 0.5-9 h, and the reaction temperature is 30-80℃. For example, the reaction time of the polymerization reaction includes, but is not limited to, 0.5 h, 3 h, 4.5 h, 6 h, 7.5 h, 9 h, or a range formed by any two of them; the reaction temperature includes, but is not limited to, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, or a range formed by any two of them. By controlling the reaction time and the reaction temperature of the polymerization reaction in the above range, the polyurethane solid-solid phase change material with good thermal stability and thermal conductivity can be prepared.

[0070] In another embodiment, the catalyst includes at least one of dibutyltin dilaurate, stannous octoate, and zinc octoate. The use of the above catalysts can accelerate the generation of the polyurethane solid-solid phase change material.

[0071] In another embodiment, the mass ratio of the catalyst to the polyethylene glycol is (0.001-0.02): 1, for example, but not limited to, 0.001: 1, 0.005: 1, 0.01: 1, 0.015: 1, 0.02: 1, or a range defined by any two of them. By controlling the mass ratio of the catalyst to the functional particles in the above range, the generation of the polyurethane solid-solid phase change material is facilitated.

[0072] The third aspect of the present application provides a thermal management component comprising the polyurethane solid-solid phase change material or prepared by the method described above.

[0073] The present application does not limit the structure of the thermal management component, which can be made into a film with a film-like structure or a bag or barrel-shaped package with a hollow structure by a template, and the selection can be made according to the actual needs. For example, the polyurethane solid-solid phase change material can be made into a film or a package with a hollow structure by using a polytetrafluoroethylene or polyethylene template with a predetermined structure, which plays a thermal management role between the cells inside the battery or between the cells and the outside. By making the polyurethane solid-solid phase change material into the above structure, the heat generated in the battery can be well conducted, and a better thermal management effect can be achieved.

[0074] The present application also provides a battery comprising the polyurethane solid-solid phase change material or the thermal management component described above.

[0075] When there are multiple groups of cells in the battery, the polyurethane solid-solid phase change material made into a film can be placed between two adjacent cells to manage the heat conduction between the cells.

[0076] The present application can also encapsulate the battery cells inside the package with a hollow structure made of the above-mentioned polyurethane solid-solid phase change material, conduct the heat generated by the cells during operation, manage the heat conduction between multiple encapsulated cells, and reduce the influence of the external environment on the working temperature of the cells.

[0077] After the above-mentioned film-like polyurethane solid-solid phase change material is applied to multiple groups of cells, it can also be encapsulated by using the package with a hollow structure made of the above-mentioned polyurethane solid-solid phase change material, further conducting the heat generated in the battery, and achieving a good thermal management effect.

[0078] By using the polyurethane solid-solid phase change material or the thermal management component described above, the battery exhibits good thermal management capability.

[0079] Example 1

[0080] The preparation method of the polyurethane solid-solid phase change material of the present embodiment comprises the following steps:

[0081] 1) Hydroxylated Fe304 (706 mg), triethylamine (15 mL), hexachlorocyclotriphosphazene (0.92 g, 2.6 mmol) and 4,4-dihydroxydiphenol (2.64 g, 10.4 mmol) and 10 mL of tetrahydrofuran were sequentially added into a sample bottle, and reacted under ultrasonic oscillation for 2-6 h; after the reaction was completed, the functional particles Fe304@PZS were purified by magnetic separation using a magnet.

[0082] 2) Under an inert atmosphere, hexamethylene diisocyanate trimer (HDI, 0.84 g, 5 mmol), functional particles Fe304@PZS (1 g) were added into a sample bottle, 5 mL of acetonitrile was added and stirred for 0.5 h to obtain a uniform solution.

[0083] 3) PEG4000 (30 g, 7.5 mmol) was added to the above uniform solution, and uniformly stirred for 2 h to obtain a polymer skeleton; 0.1 g of dibutyltin dilaurate was added dropwise as a catalyst, and uniformly stirred for 0.5 h to obtain a solution containing a polyurethane solid-solid phase change material.

[0084] 4) Under an inert atmosphere, the above solution containing the polyurethane solid-solid phase change material was uniformly coated onto a polytetrafluoroethylene template by a coating method, and the scraped polytetrafluoroethylene plate was placed in an oven at 60°C for drying for 6 h, and then heated to 80°C for drying for 12 h to obtain a polyurethane solid-solid phase change material.

[0085] The results are shown in Table 1.

[0086] Example 2

[0087] The preparation method of the polyurethane solid-solid phase change material of this example is basically the same as that of Example 1, except that in this example, the mass of hexamethylene diisocyanate trimer, polyethylene glycol and functional particles is 0.63 g (3.75 mmol), 30 g (7.5 mmol) and 1 g, respectively.

[0088] The results are shown in Table 1.

[0089] Example 3

[0090] The preparation method of the polyurethane solid-solid phase change material of this example is basically the same as that of Example 1, except that in this example, the mass of hexamethylene diisocyanate trimer, polyethylene glycol and functional particles is 0.42 g (2.5 mmol), 30 g (7.5 mmol) and 1 g, respectively.

[0091] The results are shown in Table 1.

[0092] Example 4

[0093] The preparation method of the polyurethane solid-solid phase change material of the present example is basically the same as that of Example 1, except that in the present example, the mass ratio of the functional particles to the total mass of the polyethylene glycol and the hexamethylene diisocyanate trimer is 0.005:1.

[0094] The results are shown in Table 1.

[0095] Example 5

[0096] The preparation method of the polyurethane solid-solid phase change material of the present example is basically the same as that of Example 1, except that in the present example, the mass ratio of the functional particles to the total mass of the polyethylene glycol and the hexamethylene diisocyanate trimer is 0.02:1.

[0097] The results are shown in Table 1.

[0098] Example 6

[0099] The preparation method of the polyurethane solid-solid phase change material of the present example is basically the same as that of Example 1, except that in the present example, the mass ratio of the functional particles to the total mass of the polyethylene glycol and the hexamethylene diisocyanate trimer is 0.05:1.

[0100] The results are shown in Table 1.

[0101] Example 7

[0102] The preparation method of the polyurethane solid-solid phase change material of the present example is basically the same as that of Example 1, except that in the present example, the mass ratio of the functional particles to the total mass of the polyethylene glycol and the hexamethylene diisocyanate trimer is 0.08:1.

[0103] The results are shown in Table 1.

[0104] Example 8

[0105] The preparation method of the polyurethane solid-solid phase change material of the present example is basically the same as that of Example 1, except that the mass proportion of Fe3O4 in the functional particles is 40%.

[0106] Comparative Example 1

[0107] The preparation method of the polyurethane solid-solid phase change material of the present example is basically the same as that of Example 1, except that in step 2), no functional particles are added.

[0108] The results are shown in Table 1.

[0109] Comparative Example 2

[0110] The preparation method of the polyurethane solid-solid phase change material of the present example is basically the same as that of Example 1, except that in step 2), no hexamethylene diisocyanate is added.

[0111] The results are shown in Table 1.

[0112] Comparative Example 3

[0113] The preparation method of the polyurethane solid-solid phase change material of this example is basically the same as that of Example 1, except that no Fe3O4 is added in step 1).

[0114] The results are shown in Table 1.

[0115] Comparative Example 4

[0116] The preparation method of the polyurethane solid-solid phase change material of this example is basically the same as that of Example 1, except that no HDI and functional particles are added in step 2).

[0117] The results are shown in Table 1.

[0118] Test Example 1

[0119] The polyurethane solid-solid phase change materials in the above examples and comparative examples are characterized by Fourier infrared spectroscopy: at 3400 cm -1 and 945 cm -1 , OH absorption peak and C-O-C absorption peak, respectively; at 2276 cm -1 , NCO absorption peak, at 1700 cm -1 , C=O absorption peak; at 3500 cm -1 , new NH absorption peak after HDI and PEG polymerization; at 882 cm -1 , 1153 cm -1 , 1184 cm -1 , 1490 cm -1 , P-N, O=S=O, P=N, C=C absorption peaks in PZS, respectively).

[0120] Test Example 2

[0121] The polyurethane solid-solid phase change materials in the above examples and comparative examples are tested by thermogravimetry, electrical conductivity test and DSC test to obtain the thermal decomposition temperature, thermal conductivity, melting temperature, crystallization temperature, melting enthalpy, crystallization enthalpy parameters of the materials.

[0122] The above parameters are tested by thermogravimetry and DSC test (GB / T 19466.1-2004), thermal conductivity (GB / T 10294-2008).

[0123] Table 1 Test results of fuel cell gas diffusion layers prepared in Examples 1-8 and Comparative Examples 1-4

[0124] From the test results of the examples and comparative examples of the present application, it can be seen that:

[0125] The thermal management performance of the battery is better than that of Comparative Examples 1-4 by using the polyurethane solid-solid phase change material in Examples 1-8. The thermal stability and thermal conductivity of the polyurethane solid-solid phase change material can be improved by adding Fe3O4@PZS.

[0126] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A polyurethane solid-solid phase change material, wherein, The functional particle comprises a Fe3O4 core and a PZS shell layer covering at least part of a surface of the Fe3O4 core. The polymer framework comprises a first structure from polyethylene glycol and a second structure from an isocyanate compound.

2. The polyurethane solid-solid phase change material of claim 1, wherein, The mass ratio of the functional particle to the polymer framework is (0.002-0.09):

1.

3. The polyurethane solid-solid phase change material according to claim 1 or 2, wherein, The mass ratio of the second structure to the first structure in the polymer framework is (0.01-0.2):

1.

4. The polyurethane solid-solid phase change material according to any one of claims 1-3, wherein, The mass ratio of the Fe3O4 core in the functional particle is 20-80%.

5. The polyurethane solid-solid phase change material of claim 1 or 2, wherein, The isocyanate compound comprises at least one of diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and naphthalene diisocyanate.

6. The polyurethane solid-solid phase change material according to any one of claims 1-5, wherein, The polyurethane solid-solid phase change material is prepared by a method comprising the following steps: adding polyethylene glycol to a dispersion liquid comprising an isocyanate compound and a functional particle, initiating a polymerization reaction, and obtaining the polyurethane solid-solid phase change material.

7. The polyurethane solid-solid phase change material of claim 2 or 3, wherein, The mass ratio of the isocyanate compound to polyethylene glycol is (0.01-0.25):1; and / or the mass ratio of the functional particle to the total mass of the polyethylene glycol and the isocyanate compound is (0.005-0.1):

1.

8. The polyurethane solid-solid phase change material according to any one of claims 1-7, wherein, The functional particle is prepared by a method comprising the following process: mixing Fe3O4, an alkaline catalyst, a compound of formula (N3P3)n n Cl m , a diphenol compound, and a solvent and reacting to obtain the functional particle, wherein n is a positive number and m = 1 or 2.

9. The polyurethane solid-solid phase change material of claim 4, wherein, The mass ratio of the Fe3O4 in the functional particle is 20-80%.

10. A process for the preparation of the polyurethane solid-solid phase change material of any one of claims 1 to 9, wherein, The method comprises the following steps: 1) dispersing an isocyanate compound and a functional particle in an organic solvent under an inert atmosphere to obtain a dispersion liquid; 2) adding polyethylene glycol to the dispersion liquid under an inert atmosphere, adding a catalyst dropwise, and performing a polymerization reaction to obtain the polyurethane solid-solid phase change material.

11. The method of making a polyurethane solid-solid phase change material of claim 10, wherein, The method further comprises the following steps: drying the reaction liquid of the polymerization reaction at 60°C for 6-12 hours under an inert atmosphere, and then drying the reaction liquid at 80°C for 6-12 hours to obtain the polyurethane solid-solid phase change material.

12. The method of making a polyurethane solid-solid phase change material according to claim 10 or 11, wherein, The organic solvent comprises at least one of anhydrous ethanol, tetrahydrofuran, ethyl acetate, acetonitrile, dichloromethane, chloroform, dimethylformamide, and polybutylene succinate diol; and / or The volume-to-mass ratio of the organic solvent to the solute is 2-4 L / g; and / or The dispersion time is 0.5-3 hours, and the dispersion temperature is 30-80°C; and / or The reaction time of the polymerization reaction is 0.5-9 hours, and the reaction temperature is 30-80°C; and / or The catalyst comprises at least one of dibutyltin dilaurate, stannous octoate, and zinc octoate; and / or The mass ratio of the catalyst to polyethylene glycol is (0.001-0.02):

1.

13. A thermal management component, wherein, The polyurethane solid-solid phase change material comprises any one of claims 1-9 or is prepared by the method of any one of claims 10-12.

14. A battery, wherein, The polyurethane solid-solid phase change material comprises any one of claims 1-9 or is prepared by the method of any one of claims 10-12.

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