Preparation method of graphene cooling liquid for liquid cooling of charging pile

Abstract

The invention relates to the technical field of cooling liquid preparation, in particular to a preparation method of graphene cooling liquid for charging pile liquid cooling. The method comprises the following steps: respectively dispersing expanded graphite and sodium carboxymethyl cellulose in a first modifier, carrying out ultrasonic treatment and homogenization to form a homogeneous solution, and stirring for a period of time to obtain a modified graphite dispersion liquid; wherein the weight part ratio of the expanded graphite to the sodium carboxymethyl cellulose to the modifier is 10: (3-5): (1-2); performing ultrasonic treatment and homogenization on inorganic nano powder and a second modifier to form a uniform solution, and stirring for a period of time to obtain an inorganic powder dispersion liquid; the ratio of the inorganic nano powder to the second modifier in parts by weight is (0.7-1.3): 1; and mixing a dispersing agent, a coupling agent, the modified graphene dispersion liquid and the inorganic powder dispersion liquid to obtain the graphene cooling liquid. The graphene is modified, so that the dispersion stability of the graphene in an aqueous solvent or transparent resin is improved, agglomeration among graphene sheet materials is avoided, and the graphene sheet materials are dispersed stably and uniformly.

Description

Technical Field

[0001] The present invention relates to the technical field of coolant preparation, and in particular to a method for preparing a graphene coolant for liquid cooling of a charging pile. Background Art

[0002] Graphene is a single-layer sheet material composed of carbon atoms in the form of sp 2 The hybrid orbitals are bonded and tightly stacked into a two-dimensional honeycomb lattice structure. Each carbon atom contains an unbonded electron that moves freely in the plane formed by the carbon atom. The carrier mobility of graphene is as high as 15000cm at room temperature. 2 / (V·s), which makes graphene have excellent electrical conductivity, high strength (Young's modulus reaches 1TPa), high thermal conductivity (5300W / (m·k) at room temperature), and extremely high surface area (2630m 2 / g), which is considered to be a new generation of revolutionary materials after silicon. The emergence of new graphene materials provides a new technical approach for the development of a new generation of functional coatings. Because graphene has a unique two-dimensional layered structure, it is evenly dispersed in the coating, and the high thermal conductivity within the graphene layer allows heat to be quickly dispersed throughout the sheet. These characteristics make it very suitable for use in the field of heat dissipation.

[0003] There are three main ways of heat transfer, namely heat conduction, heat convection and heat radiation. Among them, heat conduction is mainly to quickly export the generated heat to the surface of the product radiator, while heat convection and heat radiation are mainly to dissipate the heat on the surface of the radiator to the environment. In many fields that require efficient heat dissipation, due to the constraints of space, size and environment, it is impossible to exchange heat by accelerating convection. In recent years, liquid cooling heat transfer technology has developed rapidly, and the intensification of the world energy crisis has promoted its rise in the civilian field. The key to strengthening surface heat transfer technology lies in the thermal conduction of interface materials. However, many of them are graphene nanofluids, which transfer the heat inside the device to the external radiator through a heat pipe. The heat dissipation efficiency of the radiator is very limited. Only 30% of the heat inside the device is transferred out, and the residual heat is stored in the nanofluid and continues to circulate in the liquid cooling module. The overall heat transfer efficiency is low. In order to solve this technical problem, a method for preparing graphene coolant for liquid cooling of charging piles is proposed. Summary of the invention

[0004] In order to solve the technical problems existing in the above-mentioned prior art, the present invention provides a method for preparing graphene coolant for liquid cooling of charging piles.

[0005] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions: In a first aspect, in one embodiment provided by the present invention, a method for preparing a graphene coolant for liquid cooling of a charging pile is provided, the method comprising the following steps: Dispersing expanded graphite and sodium carboxymethyl cellulose in the first modifier respectively, forming a uniform solution after ultrasonication and homogenization, and stirring for a period of time to obtain a modified graphite dispersion; wherein the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is: 10:3-5:1-2; The inorganic nano powder and the second modifier are subjected to ultrasound and homogenization to form a uniform solution, and then stirred for a period of time to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 0.7 to 1.3 parts by weight: 1; 1 to 5 parts by weight of a dispersant, 1 to 3 parts by weight of a coupling agent, 3 to 10 parts by weight of a modified graphene dispersion and 10 to 25 parts by weight of an inorganic powder dispersion are mixed to obtain a graphene coolant.

[0006] As a further embodiment of the present invention, expanded graphite and sodium carboxymethyl cellulose are dispersed in a first modifier, respectively, and a uniform solution is formed after ultrasonication and homogenization, and then stirred for a period of time to obtain a modified graphite dispersion, wherein the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is 10:3-5:1-2, including: The reaction was stirred at 45-65°C for 1.5-2.8 hours.

[0007] As a further embodiment of the present invention, expanded graphite and sodium carboxymethyl cellulose are dispersed in a first modifier, respectively, and a uniform solution is formed after ultrasonication and homogenization, and then stirred for a period of time to obtain a modified graphite dispersion; wherein the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is 10:3-5:1-2, including: The reaction coating is stirred at a temperature of 55 to 60° C. for 2.0 to 2.5 hours; the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is 10:3.5 to 4.5:1 to 2.

[0008] As a further solution of the present invention, expanded graphite and sodium carboxymethyl cellulose are dispersed in a first modifier, respectively, and a uniform solution is formed after ultrasonication and homogenization, and then stirred for a period of time to obtain a modified graphite dispersion; wherein the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is 10:3-5:1-2, including: The reaction was stirred and coated at 58° C. for 2.3 h. The weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier was 10:4:1.5.

[0009] As a further embodiment of the present invention, the second modifier is modified starch or montmorillonite.

[0010] As a further solution of the present invention, the inorganic nano powder and the second modifier are subjected to ultrasound and homogenization to form a uniform solution, and then stirred for a period of time to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 0.7 to 1.3 parts by weight: 1, comprising: The reaction was stirred at 45-65°C for 1.5-2.8 hours.

[0011] As a further solution of the present invention, the inorganic nano powder and the second modifier are subjected to ultrasound and homogenization to form a uniform solution, and then stirred for a period of time to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 0.7 to 1.3 parts by weight: 1. It includes: The reaction coating is stirred at a temperature of 55 to 60° C. for 2.0 to 2.5 hours; the ratio of the inorganic nano powder to the second modifier is 0.8 to 1.2 parts by weight: 1.

[0012] As a further solution of the present invention, the inorganic nano powder and the second modifier are subjected to ultrasound and homogenization to form a uniform solution, and then stirred for a period of time to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 0.7 to 1.3 parts by weight: 1. It includes: The coating reaction was stirred at 58° C. for 2.3 h; the ratio of the inorganic nano powder to the second modifier was 1:1 by weight.

[0013] As a further embodiment of the present invention, the dispersant is one or more of polypyrrole, epoxy, and polyurethane resins.

[0014] As a further embodiment of the present invention, the graphene coolant is obtained by mixing 1 to 5 parts by weight of a dispersant, 1 to 3 parts by weight of a coupling agent, 3 to 10 parts by weight of a modified graphene dispersion and 10 to 25 parts by weight of an inorganic powder dispersion, comprising: 2 to 4 parts by weight of a dispersant, 1.5 to 2.5 parts by weight of a coupling agent, 5 to 8 parts by weight of a modified graphene dispersion and 15 to 20 parts by weight of an inorganic powder dispersion are mixed to obtain a graphene coolant.

[0015] The technical solution provided by the present invention has the following beneficial effects: The present invention modifies graphene to improve the dispersion and stability of graphene in aqueous solvents or transparent resins, avoids agglomeration between graphene sheet materials, and makes the dispersion stable and uniform. At the same time, the surface of the inorganic thermal conductive powder is modified and the surface is modified to make it stably dispersed in the aqueous solvent. The present invention prepares a few layers of graphene (≤4 layers) and effectively avoids the aggregation and stacking of graphene layers, and compounding inorganic heat dissipation powders to construct a high thermal conductivity and high heat dissipation network, so as to achieve rapid and effective heat transfer to the outside of the liquid cooling module, improve the heat dissipation efficiency of the heat-generating devices of the charging pile, and reduce the overall temperature of the system. It is particularly suitable for device modules packaged inside insulating materials or in an insulating environment.

[0016] These and other aspects of the present invention will be more clearly understood in the following description of the embodiments. It should be understood that the above general description and the following detailed description are only exemplary and explanatory and cannot limit the present invention. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] The present invention provides a method for preparing a graphene coolant for liquid cooling of a charging pile, and the method for preparing a graphene coolant for liquid cooling of a charging pile comprises the following steps: S1. Dispersing expanded graphite and sodium carboxymethyl cellulose in a first modifier respectively, forming a uniform solution after ultrasonication and homogenization, and stirring for a period of time to obtain a modified graphite dispersion; wherein the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is: 10:3-5:1-2.

[0019] In an embodiment of the present invention, the first modifier is succinic acid.

[0020] Said S1, dispersing expanded graphite and sodium carboxymethyl cellulose in a first modifier respectively, forming a uniform solution after ultrasonication and homogenization, and then stirring for a period of time to obtain a modified graphite dispersion, wherein the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is: 10:3-5:1-2, including: The reaction was stirred at 45-65°C for 1.5-2.8 hours.

[0021] In the embodiment of the present invention, the S1, expandable graphite and sodium carboxymethyl cellulose are dispersed in the first modifier respectively, and a uniform solution is formed after ultrasonication and homogenization, and then stirred for a period of time to obtain a modified graphite dispersion; wherein the weight ratio of expandable graphite, sodium carboxymethyl cellulose and modifier is: 10:3-5:1-2, including: The reaction coating is stirred at a temperature of 55 to 60° C. for 2.0 to 2.5 hours; the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is 10:3.5 to 4.5:1 to 2.

[0022] In the embodiment of the present invention, the S1, expandable graphite and sodium carboxymethyl cellulose are dispersed in the first modifier respectively, and a uniform solution is formed after ultrasonication and homogenization, and then stirred for a period of time to obtain a modified graphite dispersion; wherein the weight ratio of expandable graphite, sodium carboxymethyl cellulose and modifier is: 10:3-5:1-2, including: The reaction was stirred and coated at 58° C. for 2.3 h. The weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier was 10:4:1.5.

[0023] S2. The inorganic nano powder and the second modifier are subjected to ultrasonication and homogenization to form a uniform solution, and then stirred for a period of time to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 0.7 to 1.3:1 by weight.

[0024] In an embodiment of the present invention, the second modifier is modified starch or montmorillonite.

[0025] S2, subjecting the inorganic nano powder and the second modifier to ultrasonic and homogenization to form a uniform solution, and then stirring for a period of time to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 0.7 to 1.3 parts by weight: 1, comprising: The reaction was stirred at 45-65°C for 1.5-2.8 hours.

[0026] In the embodiment of the present invention, S2, the inorganic nano powder and the second modifier are subjected to ultrasound and homogenization to form a uniform solution, and then stirred for a period of time to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 0.7 to 1.3 parts by weight: 1. Including: The reaction coating is stirred at a temperature of 55 to 60° C. for 2.0 to 2.5 hours; the ratio of the inorganic nano powder to the second modifier is 0.8 to 1.2 parts by weight: 1.

[0027] In the embodiment of the present invention, S2, the inorganic nano powder and the second modifier are subjected to ultrasound and homogenization to form a uniform solution, and then stirred for a period of time to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 0.7 to 1.3 parts by weight: 1. Including: The coating reaction was stirred at 58° C. for 2.3 h; the ratio of the inorganic nano powder to the second modifier was 1:1 by weight.

[0028] S3. Mix 1 to 5 parts by weight of a dispersant, 1 to 3 parts by weight of a coupling agent, 3 to 10 parts by weight of a modified graphene dispersion and 10 to 25 parts by weight of an inorganic powder dispersion to obtain a graphene coolant.

[0029] The dispersant is one or more of polypyrrole, epoxy and polyurethane resins.

[0030] In an embodiment of the present invention, S3, mixing 1 to 5 parts by weight of a dispersant, 1 to 3 parts by weight of a coupling agent, 3 to 10 parts by weight of a modified graphene dispersion and 10 to 25 parts by weight of an inorganic powder dispersion to obtain a graphene coolant; comprising: 2 to 4 parts by weight of a dispersant, 1.5 to 2.5 parts by weight of a coupling agent, 5 to 8 parts by weight of a modified graphene dispersion and 15 to 20 parts by weight of an inorganic powder dispersion are mixed to obtain a graphene coolant.

[0031] In an embodiment of the present invention, S3, mixing 1 to 5 parts by weight of a dispersant, 1 to 3 parts by weight of a coupling agent, 3 to 10 parts by weight of a modified graphene dispersion and 10 to 25 parts by weight of an inorganic powder dispersion to obtain a graphene coolant; comprising: 3 parts by weight of a dispersant, 2 parts by weight of a coupling agent, 6 parts by weight of a modified graphene dispersion and 17 parts by weight of an inorganic powder dispersion are mixed to obtain a graphene coolant.

[0032] The present invention modifies graphene to improve the dispersion and stability of graphene in aqueous solvents or transparent resins, avoids agglomeration between graphene sheet materials, and makes the dispersion stable and uniform. At the same time, the surface of the inorganic thermal conductive powder is modified and the surface is modified to make it stably dispersed in the aqueous solvent. The present invention prepares a few layers of graphene (≤4 layers) and effectively avoids the aggregation and stacking of graphene layers, and compounding inorganic heat dissipation powders to construct a high thermal conductivity and high heat dissipation network, so as to achieve rapid and effective heat transfer to the outside of the liquid cooling module, improve the heat dissipation efficiency of the heat-generating devices of the charging pile, and reduce the overall temperature of the system. It is particularly suitable for device modules packaged inside insulating materials or in an insulating environment.

[0033] Example 1 A method for preparing graphene coolant for charging pile liquid cooling comprises the following steps: S1. Disperse expanded graphite and sodium carboxymethyl cellulose in the first modifier respectively, form a uniform solution after ultrasonication and homogenization, and stir the reaction coating at 65°C for 12.8h to obtain a modified graphite dispersion; wherein the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is 10:5:2.

[0034] In an embodiment of the present invention, the first modifier is succinic acid.

[0035] S2. The inorganic nano powder and the second modifier are subjected to ultrasound and homogenization to form a uniform solution, and the solution is stirred for reaction and coating at a temperature of 45 to 65° C. for 1.5 to 2.8 hours to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 1.3:1 by weight.

[0036] In an embodiment of the present invention, the second modifier is modified starch.

[0037] S3. Mix 5 parts by weight of a dispersant, 3 parts by weight of a coupling agent, 10 parts by weight of a modified graphene dispersion and 10 parts by weight of an inorganic powder dispersion to obtain a graphene coolant.

[0038] The dispersant is one or more of polypyrrole, epoxy and polyurethane resins.

[0039] Example 2 A method for preparing graphene coolant for charging pile liquid cooling comprises the following steps: S1. Disperse expanded graphite and sodium carboxymethyl cellulose in the first modifier respectively, form a uniform solution after ultrasonication and homogenization, and stir the reaction coating at 45°C for 1.5h to obtain a modified graphite dispersion; wherein the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is 10:3:1.

[0040] In an embodiment of the present invention, the first modifier is succinic acid.

[0041] S2. The inorganic nano powder and the second modifier are subjected to ultrasound and homogenization to form a uniform solution, and the solution is stirred for reaction and coating at a temperature of 45 to 65° C. for 1.5 to 2.8 hours to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 0.7:1 by weight.

[0042] In the embodiment of the present invention, the second modifier is montmorillonite.

[0043] S3. Mix 1 part of dispersant, 1 part of coupling agent, 3 parts of modified graphene dispersion and 25 parts of inorganic powder dispersion by weight to obtain graphene coolant.

[0044] The dispersant is one or more of polypyrrole, epoxy and polyurethane resins.

[0045] Example 3 A method for preparing graphene coolant for charging pile liquid cooling comprises the following steps: S1. Disperse expanded graphite and sodium carboxymethyl cellulose in the first modifier respectively, form a uniform solution after ultrasonication and homogenization, and stir the reaction coating at 60°C for 2.5h to obtain a modified graphite dispersion; wherein the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is 10:4.5:2.

[0046] In an embodiment of the present invention, the first modifier is succinic acid.

[0047] S2. The inorganic nano powder and the second modifier are subjected to ultrasound and homogenization to form a uniform solution, and the solution is stirred for reaction and coating at 55-60° C. for 2.5 h to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 1.2:1 by weight.

[0048] In the embodiment of the present invention, the second modifier is montmorillonite.

[0049] S3. Mix 4 parts by weight of a dispersant, 2.5 parts by weight of a coupling agent, 8 parts by weight of a modified graphene dispersion and 15 parts by weight of an inorganic powder dispersion to obtain a graphene coolant.

[0050] The dispersant is one or more of polypyrrole, epoxy and polyurethane resins.

[0051] Example 4 A method for preparing graphene coolant for charging pile liquid cooling comprises the following steps: S1. Disperse expanded graphite and sodium carboxymethyl cellulose in the first modifier respectively, form a uniform solution after ultrasonication and homogenization, and stir the reaction coating at 55°C for 2.0h to obtain a modified graphite dispersion; wherein the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is 10:3.5:1.

[0052] In an embodiment of the present invention, the first modifier is succinic acid.

[0053] S2. The inorganic nano powder and the second modifier are subjected to ultrasound and homogenization to form a uniform solution, and the solution is stirred for reaction and coating at 55° C. for 2.0 h to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 0.8:1 by weight.

[0054] In the embodiment of the present invention, the second modifier is montmorillonite.

[0055] S3. Mix 2 parts by weight of a dispersant, 1.5 parts by weight of a coupling agent, 5 parts by weight of a modified graphene dispersion, and 20 parts by weight of an inorganic powder dispersion to obtain a graphene coolant.

[0056] The dispersant is one or more of polypyrrole, epoxy and polyurethane resins.

[0057] Example 5 A method for preparing graphene coolant for charging pile liquid cooling comprises the following steps: S1. Disperse expanded graphite and sodium carboxymethyl cellulose in the first modifier respectively, form a uniform solution after ultrasonication and homogenization, and stir the reaction coating at 58°C for 2.3h to obtain a modified graphite dispersion; wherein the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is 10:4:1.5.

[0058] In an embodiment of the present invention, the first modifier is succinic acid.

[0059] S2. The inorganic nano powder and the second modifier are subjected to ultrasonication and homogenization to form a uniform solution, and then stirred for a period of time to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 1:1 by weight.

[0060] In the embodiment of the present invention, the second modifier is montmorillonite.

[0061] S3. Mix 3 parts by weight of a dispersant, 2 parts by weight of a coupling agent, 6 parts by weight of a modified graphene dispersion and 17 parts by weight of an inorganic powder dispersion to obtain a graphene coolant.

[0062] The dispersant is one or more of polypyrrole, epoxy and polyurethane resins.

[0063] The graphene coolant prepared by the present invention has a viscosity of 2000cp, a solid content of 16%, and a thermal conductivity of 30W / mk. The prepared coolant can be used in automotive liquid cooling equipment, new energy liquid cooling devices, IGBT liquid cooling heat dissipation devices, and liquid cooling charging piles. It has low cost, is halogen-free, non-toxic, and environmentally friendly, and complies with green and environmentally friendly raw materials.

[0064] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A method for preparing graphene coolant for charging pile liquid cooling, characterized in that: The method comprises: dispersing expanded graphite and sodium carboxymethyl cellulose in a first modifier respectively, forming a uniform solution after ultrasonication and homogenization, and stirring for a period of time to obtain a modified graphite dispersion; wherein the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is 10:3-5:1-2; The inorganic nano powder and the second modifier are subjected to ultrasound and homogenization to form a uniform solution, and then stirred for a period of time to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 0.7 to 1.3 parts by weight: 1; 1 to 5 parts by weight of a dispersant, 1 to 3 parts by weight of a coupling agent, 3 to 10 parts by weight of a modified graphene dispersion and 10 to 25 parts by weight of an inorganic powder dispersion are mixed to obtain a graphene coolant.

2. The method for preparing graphene coolant for charging pile liquid cooling according to claim 1, characterized in that: Expanded graphite and sodium carboxymethyl cellulose are dispersed in the first modifier respectively, and a uniform solution is formed after ultrasonication and homogenization, and then stirred for a period of time to obtain a modified graphite dispersion, wherein the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is 10:3-5:1-2, including: The reaction was stirred at 45-65°C for 1.5-2.8 hours.

3. The method for preparing graphene coolant for charging pile liquid cooling according to claim 3, characterized in that: Expanded graphite and sodium carboxymethyl cellulose are dispersed in the first modifier respectively, and a uniform solution is formed after ultrasonic and homogenization, and then stirred for a period of time to obtain a modified graphite dispersion; wherein the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is 10:3-5:1-2, including: The reaction coating is stirred at a temperature of 55 to 60° C. for 2.0 to 2.5 hours; the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is 10:3.5 to 4.5:1 to 2.

4. The method for preparing graphene coolant for charging pile liquid cooling according to claim 3, characterized in that: Expanded graphite and sodium carboxymethyl cellulose are dispersed in the first modifier respectively, and a uniform solution is formed after ultrasonication and homogenization, and then stirred for a period of time to obtain a modified graphite dispersion; wherein the weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier is 10:3-5:1-2, including: The reaction was stirred and coated at 58° C. for 2.3 h. The weight ratio of expanded graphite, sodium carboxymethyl cellulose and modifier was 10:4:1.

5.

5. The method for preparing graphene coolant for charging pile liquid cooling according to claim 1, characterized in that: The second modifier is modified starch or montmorillonite.

6. The method for preparing graphene coolant for charging pile liquid cooling according to claim 1, characterized in that: The inorganic nano powder and the second modifier are subjected to ultrasound and homogenization to form a uniform solution, and then stirred for a period of time to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 0.7 to 1.3 parts by weight: 1, comprising: The reaction was stirred at 45-65°C for 1.5-2.8 hours.

7. The method for preparing graphene coolant for charging pile liquid cooling according to claim 6, characterized in that: The inorganic nano powder and the second modifier are subjected to ultrasonic and homogenization to form a uniform solution, and then stirred for a period of time to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 0.7 to 1.3 parts by weight:

1. Including: The reaction coating is stirred at a temperature of 55 to 60° C. for 2.0 to 2.5 hours; the ratio of the inorganic nano powder to the second modifier is 0.8 to 1.2 parts by weight:

1.

8. The method for preparing graphene coolant for charging pile liquid cooling according to claim 7, characterized in that: The inorganic nano powder and the second modifier are subjected to ultrasonic and homogenization to form a uniform solution, and then stirred for a period of time to obtain an inorganic powder dispersion; the ratio of the inorganic nano powder to the second modifier is 0.7 to 1.3 parts by weight:

1. Including: The reaction coating was stirred at 58° C. for 2.3 h; the ratio of the inorganic nano powder to the second modifier was 1:1 by weight.

9. The method for preparing graphene coolant for charging pile liquid cooling according to claim 1, characterized in that: The dispersant is one or more of polypyrrole, epoxy and polyurethane resins.

10. The method for preparing graphene coolant for charging pile liquid cooling according to claim 1, characterized in that: The method comprises mixing 1 to 5 parts by weight of a dispersant, 1 to 3 parts by weight of a coupling agent, 3 to 10 parts by weight of a modified graphene dispersion and 10 to 25 parts by weight of an inorganic powder dispersion to obtain a graphene coolant, comprising: 2 to 4 parts by weight of a dispersant, 1.5 to 2.5 parts by weight of a coupling agent, 5 to 8 parts by weight of a modified graphene dispersion and 15 to 20 parts by weight of an inorganic powder dispersion are mixed to obtain a graphene coolant.