Driving oil for power of new energy hybrid electric vehicle and preparation method of driving oil

Abstract

The invention discloses driving oil for new energy hybrid power automobile power and a preparation method thereof, and particularly relates to the technical field of driving oil, the driving oil comprises 70-85% of base oil, 0.8-2.5% of a conductive inhibitor, 1-3% of a nanometer heat conduction agent, 4-8% of a viscosity index improver, 0.1-0.5% of an ion trapping agent, 3-5% of an anti-wear reagent at extreme pressure, 0.5-1.5% of an antioxidant and 0.001-0.01% of an anti-foaming agent. The preparation method comprises the following steps: S1, base oil pretreatment, S2, nano heat conduction agent in-situ modification, and S3, gradient temperature control compounding. Through compounding of the base oil in a specific proportion and the synergistic effect of multiple additives, the problems of insufficient insulativity, easy oxidation, poor viscosity stability, low heat conduction efficiency, poor material compatibility and the like of traditional oil in a hybrid power system are solved, effective protection of a motor and an electric control system is realized, the heat management efficiency is improved, and the service life of the hybrid power system is prolonged. And the service life of oil is prolonged, the maintenance cost is reduced, and the special requirements of power and driving systems of hybrid vehicles are met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of driving oil, more particularly, the present application relates to a new energy hybrid vehicle power driving oil and a preparation method thereof. BACKGROUND

[0002] Under the background of global energy saving and emission reduction and sustainable development, the new energy vehicle industry is rising rapidly, among which the hybrid vehicle occupies an important share in the market due to its unique advantages. The hybrid vehicle combines traditional fuel power and electric drive, which not only effectively reduces fuel consumption and exhaust emission, but also relieves the anxiety of consumers about the range of pure electric vehicles, and is deeply favored by consumers.

[0003] However, the complexity of the hybrid vehicle power and driving system puts strict requirements on the lubricating performance, heat dissipation capacity, electrical performance and material compatibility of the oil. Although the existing oil technology has been improved, it still cannot fully meet these needs.

[0004] Therefore, the present application provides a new energy hybrid vehicle power driving oil and a preparation method thereof. SUMMARY

[0005] In order to overcome the above-mentioned defects of the prior art, the present application provides a new energy hybrid vehicle power driving oil and a preparation method thereof to solve the problems raised in the background art.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a new energy hybrid vehicle power driving oil, by weight percentage, comprising base oil 70-85%, conductive inhibitor 0.8-2.5%, nano thermal conductive agent 1-3%, viscosity index improver 4-8%, ion capture agent 0.1-0.5%, extreme pressure anti-wear agent 3-5%, antioxidant 0.5-1.5% and antifoaming agent 0.001-0.01%; The base oil is compounded by poly-alpha olefin, alkyl naphthalene and ester oil in a mass ratio of (4-6):(0.8-1.2):(1.5-2.5); The conductive inhibitor is composed of thiazole derivative, boron imidazoline and rare earth organic molybdenum in a mass ratio of (1-1.5):(0.4-0.6):(0.2-0.4); The nano thermal conductive agent is an alumina nanoparticle coated with a polydopamine-siloxane hybrid layer, with a particle size of 20-50 nm and a hybrid layer thickness of 5-8 nm; The viscosity index improver is a poly-N-isopropyl acrylamide-styrene block copolymer; The ion capture agent is a porous covalent organic framework COF material.

[0007] Preferably, the polydopamine-siloxane hybrid layer of the nano-thermal conductor contains sulfonic acid groups and is combined with the base oil through a hydrogen bond network, so that the nanoparticle has a dispersion stability D90 value ≤ 100 nm in the temperature range of -40 to 180 ℃.

[0008] Preferably, the ion capture agent is a two-dimensional COF material with an imine bond, the pore size is 1.2-1.8 nm, and the specific surface area is ≥800 m 2 / g, for selectively adsorbing free Cu 2+ and Fe 3+ ions in oil.

[0009] Preferably, in the poly-N-isopropyl acrylamide-styrene block copolymer of the viscosity index improver, the molecular weight of the poly-N-isopropyl acrylamide segment is 5000-8000 g / mol, and the molecular weight of the styrene segment is 3000-5000 g / mol.

[0010] Preferably, the alkyl naphthalene in the base oil is diisopropyl naphthalene, and the kinematic viscosity at -50℃ is ≤1200 cSt, and the ester oil is pentaerythritol ester.

[0011] Preferably, the extreme pressure anti-wear agent is a mixture of ashless sulfur phosphorus compound and borate ester in a mass ratio of (2.5-3.5):1, wherein; the sulfur phosphorus compound is selected from at least one of ammonium dialkyldithiophosphate and trimethylphenyl phosphite; the borate ester is triethanolamine borate, and the boron content is ≥8 wt%.

[0012] Preferably, the antioxidant is compounded by N-phenyl-α-naphthylamine and 2,6-di-tert-butyl-p-cresol in a ratio of (1-1.2):1, and cooperates with the rare earth organic molybdenum in the conductivity inhibitor to reduce the copper catalytic oxidation rate by more than 40%.

[0013] Preferably, the antifoaming agent is polydimethylsiloxane.

[0014] The application also provides a preparation method for preparing the new energy hybrid vehicle power driving oil liquid. S1, base oil pretreatment, mixing and stirring polyalphaolefin, alkyl naphthalene and ester oil at 60±5℃ for 30 min, vacuum dehydration to moisture ≤50 ppm, to obtain base oil; S2, in-situ modification of nano-thermal conductor, adding aluminum oxide nanoparticles and dopamine hydrochloride to the base oil obtained in step S1, and ultrasonic treatment at 40 kHz for 1.5-2 h under nitrogen protection, and simultaneously completing the polymerization of the polydopamine-siloxane hybrid layer on the surface of the aluminum oxide; S3, gradient temperature control, add conductive inhibitor and extreme pressure anti-wear agent at 40±2 DEG C, stir for 20 min, increase the temperature to 70±2 DEG C, add viscosity index improver, stir for 30 min, decrease the temperature to 50±2 DEG C, add ion capture agent, antioxidant and antifoaming agent, stir for 40 min, to obtain drive oil liquid; When the extreme pressure anti-wear agent is added, the sulfur phosphorus compound is added first, and the borate ester is added after 15 min.

[0015] Preferably, in the S2 step, the amount of dopamine hydrochloride added is 15-25% of the mass of the aluminum oxide nanoparticles, and nitrogen is introduced throughout the ultrasonic process and the oxygen content is controlled to be ≤10 ppm.

[0016] The technical effects and advantages of the present application are: 1. The present application overcomes the problems of insufficient insulation and the risk of electrochemical corrosion of traditional fuel vehicle lubricating oil, solves the pain points that ordinary gearbox oil and cooling liquid cannot meet the high temperature and high pressure insulation requirements of the motor and electric control system, and adapts to the working environment of the motor, electric control and transmission components in the hybrid system. 2. The present application optimizes the formula, enhances the oxidation stability and viscosity stability, improves the compatibility with motor copper wire, sealing materials and other materials, avoids copper wire corrosion and sealing material swelling and other problems, and ensures long-term reliable operation of the system. 3. The addition of nano thermal conductive agent in the oil liquid of the present application improves the thermal conductivity, solves the problem of insufficient thermal conductivity of traditional cooling liquid affecting the motor and battery thermal management, and realizes the integration of lubrication, insulation, cooling and other functions, without the need to separately equip oil liquid for different systems, simplifying the structure of the hybrid system and improving the overall operation efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The present application is a whole flow chart. DETAILED DESCRIPTION Example 1

[0018] The present application provides a new energy hybrid vehicle power drive oil liquid, comprising: Base oil, take polyalphaolefin 40 parts, alkyl naphthalene 8 parts, ester oil 15 parts, a total of 63 parts, accounting for about 70%, polyalphaolefin provides good basic lubricity and chemical stability, alkyl naphthalene improves low temperature fluidity, and ester oil improves overall lubricity and oil film strength; Conductive inhibitor, thiazole derivative 1 part, boron imidazoline 0.4 part, rare earth organic molybdenum 0.2 part, total 1.6 parts, accounting for about 0.8%, the three-component compound system synergistically inhibits current conduction and prevents corrosion of metal parts by electrochemical reaction; Nano thermal conductive agent, 1 part of alumina nanoparticles with a particle size of 20 nm and a hybrid layer thickness of 5 nm coated with a polydopamine-siloxane hybrid layer, enhances the dispersion stability of the nanoparticles in the base oil and improves the thermal conductivity; Viscosity index improver, 4 parts of poly-N-isopropyl acrylamide-styrene block copolymer, wherein the poly-N-isopropyl acrylamide segment has a molecular weight of 5000 g / mol and the styrene segment has a molecular weight of 3000 g / mol, effectively adjusts the viscosity of the oil at different temperatures to meet the complex working condition requirements of hybrid vehicles; Ion capture agent, 0.1 part of porous covalent organic framework material, which is a two-dimensional COF material with imine bonds, has a pore size of 1.2 nm and a specific surface area of 800 m² / g, is used to selectively adsorb free Cu 2+ and Fe 3+ ions in the oil, and reduces the electrochemical reactions caused by metal ions; Extreme pressure anti-wear agent, 2.5 parts of ash-free sulfur and phosphorus compounds mixed with 1 part of boric acid ester, a total of 3.5 parts, forms a protective film on the metal surface under high load conditions to reduce wear; Antioxidant, 0.5 parts of N-phenyl-alpha-naphthylamine compounded with 0.5 parts of 2,6-di-tert-butyl-p-cresol, a total of 1 part, cooperates with rare earth organic molybdenum in the conductivity inhibitor to effectively delay oil oxidation and improve service life; Antifoaming agent, 0.001 parts of polydimethylsiloxane, inhibits the generation of foam in the oil during the circulation process to ensure the stable performance of the oil.

[0019] The embodiment of the present application also provides a preparation method for preparing the new energy hybrid vehicle driving oil liquid. S1, base oil pretreatment, mix and stir polyalphaolefin, diisopropyl naphthalene and pentaerythritol ester at 55°C for 30 min, and then perform vacuum dehydration treatment until the water content is reduced to 45 ppm; S2, in-situ modification of nano thermal conductive agent, add alumina nanoparticles and dopamine hydrochloride (the amount of dopamine hydrochloride added is 15% of the mass of alumina nanoparticles) to the pretreated base oil, and perform ultrasonic treatment at 40 kHz for 1.5 h under nitrogen protection (the oxygen content is controlled to be ≤10 ppm throughout the process), and simultaneously complete the polymerization of the polydopamine-siloxane hybrid layer on the surface of alumina; S3, gradient temperature control compounding, first add diisopropyl ammonium dithiophosphate at 38°C, stir for 15 min, then add triethanolamine borate, continue to stir for 5 min, then add the conductivity inhibitor, stir for 20 min, increase the temperature to 68°C, add the viscosity index improver, stir for 30 min, reduce the temperature to 48°C, add the ion capture agent COF, the antioxidant and the antifoaming agent, and stir for 40 min to obtain the driving oil liquid. Embodiment 2

[0020] The embodiment of the present application provides a new energy hybrid vehicle power driving oil liquid, which comprises the following components: Base oil, taking poly-alpha olefin 54 parts, alkyl naphthalene 10 parts, ester oil 20 parts, a total of 84 parts, accounting for about 78%, the optimized proportion further improves the comprehensive performance of the base oil at different temperatures; Conductive inhibitor, thiazole derivative 1.2 parts, boron imidazoline 0.5 parts, and rare earth organic molybdenum 0.3 parts, a total of 2 parts, accounting for about 1.5%, and the ternary compound ratio is appropriately adjusted to enhance the corrosion inhibition synergistic effect; Nano thermal conductor, aluminum oxide nanoparticles with a surface coated with a polydopamine-siloxane hybrid layer 2 parts, particle size 35 nm, hybrid layer thickness 6 nm, and the moderate particle size and hybrid layer thickness balance the dispersibility and thermal conductivity efficiency; Viscosity index improver, poly-N-isopropyl acrylamide-styrene block copolymer 6 parts, poly-N-isopropyl acrylamide segment molecular weight 6500 g / mol, and styrene segment molecular weight 4000 g / mol, and the molecular structure is optimized to better adapt to the temperature change of the working condition; Ion capture agent, porous covalent organic framework material 0.3 parts, which is a two-dimensional COF material with an imine bond, pore size 1.5 nm, and specific surface area 900 m² / g, and the ion capture capacity is improved; Extreme pressure anti-wear agent, ash-free sulfur phosphorus compound 3 parts and borate 1 part are mixed, a total of 4 parts, the type of sulfur phosphorus compound is changed, and the influence of different components on the extreme pressure and wear resistance is tested; Antioxidant, N-phenyl-alpha-naphthylamine 0.6 parts and 2,6-di-tert-butyl-p-cresol 0.4 parts are compounded, a total of 1 part, the proportion of the antioxidant is adjusted, and the antioxidant performance is synergistically improved; Antifoam agent, polydimethylsiloxane 0.005 parts, further inhibiting the generation of foam.

[0021] The embodiment of the present application also provides a preparation method for preparing the new energy hybrid vehicle power driving oil liquid. S1, base oil pretreatment, mixing and stirring poly-alpha olefin, diisopropyl naphthalene and pentaerythritol ester at 60 DEG C for 30 min, and then performing vacuum dehydration treatment until the water content is reduced to 40 ppm; S2, in-situ modification of nano thermal conductor, adding aluminum oxide nanoparticles and dopamine hydrochloride (the amount of dopamine hydrochloride is 20% of the mass of the aluminum oxide nanoparticles) into the pretreated base oil, and performing ultrasonic treatment at 40 kHz for 1.8 h under nitrogen protection (oxygen content is controlled to be 8 ppm), so as to complete the polymerization of the polydopamine-siloxane hybrid layer on the surface of the aluminum oxide; S3, gradient temperature control, at 40 DEG C, first add phosphoric acid trimethylphenyl ester, stir for 15 min, then add triethanolamine borate, continue to stir for 5 min, then add conductive inhibitor, stir for 20 min, increase temperature to 70 DEG C, add viscosity index improver, stir for 30 min, reduce temperature to 50 DEG C, add ion capture agent COF, antioxidant and antifoaming agent, stir for 40 min, obtain drive oil liquid. Example 3

[0022] The embodiment of the application provides a new energy hybrid vehicle power drive oil liquid, which comprises: Base oil, polyalphaolefin 60 parts, alkyl naphthalene 12 parts, ester oil 25 parts, a total of 97 parts, accounting for about 85%, increasing the proportion of base oil, exploring the performance limit; Conductive inhibitor, thiazole derivative 1.5 parts, boron imidazoline 0.6 parts, rare earth organic molybdenum 0.4 parts, a total of 2.5 parts, accounting for about 2.5%, the maximum proportion of conductive inhibitor, strengthening the corrosion inhibition effect; Nanometer thermal conductor, alumina nanoparticles with polydopamine-siloxane hybrid layer on the surface 3 parts, particle size 50 nm, hybrid layer thickness 8 nm, larger particle size and thicker hybrid layer improve the thermal conductivity; Viscosity index improver, poly N-isopropyl acrylamide-styrene block copolymer 8 parts, poly N-isopropyl acrylamide segment molecular weight 8000 g / mol, styrene segment molecular weight 5000 g / mol, fully play the viscosity temperature regulation role; Ion capture agent, porous covalent organic framework material 0.5 parts, two-dimensional COF material with imine bond, pore size 1.8 nm, specific surface area 1000 m² / g, enhance the ion adsorption capacity; Extreme pressure anti-wear agent, ash-free sulfur phosphorus compound (dialkyldithiophosphoric acid ammonium and phosphoric acid trimethylphenyl ester mixed in a ratio of 1:1) 3.5 parts and borate (triethanolamine borate, boron content 9wt%) 1.5 parts mixed, a total of 5 parts, compound sulfur phosphorus compound, optimize the extreme pressure and wear resistance; Antioxidant, N-phenyl-alpha-naphthylamine 0.6 parts and 2,6-di-tert-butyl-p-cresol 0.4 parts, a total of 1 part, keep the synergistic ratio of antioxidant; Antifoaming agent, polydimethylsiloxane 0.01 parts, ensure the antifoaming performance under high proportion of additives.

[0023] The embodiment of the application also provides a preparation method for preparing the new energy hybrid vehicle power drive oil liquid, the specific steps are as follows: S1, base oil pretreatment, polyalphaolefin, diisopropyl naphthalene and pentaerythritol ester are mixed and stirred at 65 DEG C for 30 min, and then vacuum dehydration treatment is carried out until the water content is reduced to 35 ppm; S2, in-situ modification of nano-thermal conductive agent, adding alumina nanoparticles and dopamine hydrochloride (the amount of dopamine hydrochloride is 25% of the mass of alumina nanoparticles) into the pretreated base oil, under nitrogen protection (oxygen content 6 ppm), ultrasonic treatment for 2 h at 40 kHz, to complete the polymerization of the polydopamine-siloxane hybrid layer on the surface of alumina; S3, gradient temperature control compounding, first adding mixed ashless sulfur and phosphorus compounds at 42℃, stirring for 15 min, then adding triethanolamine borate, continuing to stir for 5 min, then adding conductivity inhibitor, stirring for 20 min, increasing the temperature to 72℃, adding viscosity index improver, stirring for 30 min, reducing the temperature to 52℃, adding ion capture agent COF, antioxidant and antifoaming agent, stirring for 40 min, to obtain the drive oil.

[0024] Comparative Example 1 Different from Example 2, the base oil only uses a single poly-alpha olefin 78 parts, without compounding alkyl naphthalene and ester oil in a mass ratio of (4-6):(0.8-1.2):(1.5-2.5), and other components and preparation methods are the same as Example 2; The lack of alkyl naphthalene and ester oil may result in poor low-temperature fluidity and overall lubrication performance and oil film strength of the oil, and the comprehensive performance advantage brought by the synergistic compounding of multiple base oils cannot be fully realized.

[0025] Comparative Example 2 Different from Example 2, the nano-thermal conductive agent is alumina nanoparticles without a polydopamine-siloxane hybrid layer coating, with a particle size of 35 nm, and other components and preparation methods are the same as Example 2; Without surface modification treatment, the dispersion stability of the nanoparticles in the base oil is insufficient, and it is difficult to maintain a good dispersion state in the temperature range of -40℃ to 180℃, which cannot effectively improve the thermal conductivity of the oil, and further affect the heat dissipation efficiency of the hybrid vehicle power system.

[0026] Comparative Example 3 Different from Example 2, the formulation does not contain a nano-thermal conductive agent, and other components and preparation methods are the same as Example 2; Without a nano-thermal conductive agent, the thermal conductivity of the oil will mainly depend on the base oil itself, and compared to Example 2 with a nano-thermal conductive agent, there will be a significant gap in heat transfer efficiency, which cannot meet the demand for efficient heat dissipation of the hybrid vehicle power system under complex working conditions.

[0027] In the following, the drive oil prepared in Examples 1-3 and Comparative Examples 1-3 will be tested for performance, and the test items and methods are as follows: Dielectric strength: using an insulating oil dielectric strength tester, the insulating performance of the oil is determined by the breakdown voltage between the electrodes, this index reflects the insulating performance of the oil, which is crucial for the safety of the high-voltage system of the hybrid vehicle; Copper corrosion grade: using a copper sheet corrosion tester, controlling the test temperature and time, evaluating the corrosion degree of the oil to the metal parts such as copper wire of the motor by the surface state of the copper sheet; Thermal conductivity: using a heat flow meter type thermal conductivity instrument, the heat conduction capacity of the oil is determined by the steady-state heat flow method, this index directly reflects the heat conduction capacity of the oil, which has a key influence on the thermal management efficiency of the motor and battery system; Brookfield viscosity at -40℃: using a Brookfield viscometer, equipped with a low-temperature constant temperature tank to control the test temperature, reflecting the flowability of the oil in low temperature environment, which is related to the low temperature starting performance of the hybrid vehicle; Kinematic viscosity at 100℃: using a capillary viscometer, combined with a constant temperature bath to control the temperature accuracy, reflecting the viscosity characteristics of the oil under high temperature working conditions, which determines the lubrication effect; Oxidation induction period at 150℃: using an oxidation stability tester, monitoring the oxidation process by pressure change, evaluating the antioxidant performance of the oil, which determines its service life; Nanoparticle dispersion stability: using a laser particle size analyzer to determine the D90 distribution of particles in the oil after 1000h standing, auxiliary observation of stratification, if stratification or sedimentation occurs, it indicates poor stability.

[0028] The final test table is shown in the following table: Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Dielectric strength (kV / mm) 42 45 48 28 35 32 Copper corrosion rating (GB / T 5096) 0 rating 0 rating 0 rating 2 rating 1 rating 1 rating Thermal conductivity (W / m・K) 0.175 0.182 0.190 0.132 0.150 0.128 -40℃ Brookfield viscosity (cP) 4300 4100 3900 6800 5200 5100 100℃ kinematic viscosity (cSt) 8.5 9.2 9.8 7.2 8.0 7.9 150℃ oxidation induction time (h) 1600 1800 2000 850 1100 1050 Nanoparticle dispersion stability (1000h standing) No delamination No delamination No delamination / Significant sedimentation / From the above table data, it can be seen that: 1. Insulation and corrosion resistance: the dielectric strength of examples 1-3 is 42-48kV / mm, and the copper corrosion grade is 0, which is significantly better than the dielectric strength of 28-35kV / mm and the copper corrosion grade of 1-2 of the comparative examples. It shows that the synergistic effect of poly-alpha olefin and ester oil compounded base oil, thiazole derivative and other conductive inhibitors in the present application effectively solves the problems of insufficient insulation and electrochemical corrosion of traditional oil, and meets the insulation and corrosion resistance requirements of the high-voltage system of the hybrid vehicle; 2. Thermal conductivity: the thermal conductivity of examples 1-3 is 0.175-0.190W / m・K, which is much higher than 0.128-0.150W / m・K of the comparative examples, among which, the thermal conductivity of example 2 using alumina nanoparticles coated with polydopamine-siloxane hybrid layer is obviously improved compared with the comparative example 3 without modification or without adding nano thermal conductive agent, which verifies the necessity of nano thermal conductive agent modification technology and addition, and solves the problem of insufficient cooling liquid thermal conductivity; 3. Viscosity and low temperature performance: the Brookfield viscosity of examples 1-3 at -40℃ is 3900-4300 cP, the kinematic viscosity at 100℃ is 8.5-9.8 cSt, the low temperature flowability and high temperature viscosity stability are better than those of comparative examples 1-3, which is due to the compounding of poly-alpha olefin with alkyl naphthalene and ester oil and the effect of temperature-sensitive viscosity index improver, overcoming the problem of poor viscosity stability of oil caused by frequent mode switching of the hybrid system; 4. Oxidation stability: the oxidation induction period of examples 1-3 at 150℃ is 1600-2000h, far exceeding that of comparative examples 850-1100h, and the nanoparticles do not delaminate after 1000h standing, indicating that the amine+phenolic compound antioxidant, ultrasonic dispersion and stepwise compounding process in the present application effectively improve the oxidation stability and additive dispersibility of the oil, solve the problem of easy oxidation of the oil, and prolong the service life.

[0029] In summary, the test data of the examples fully prove that the present application, through key technologies such as multifunctional integrated formula and nano material modification, makes the oil better than the traditional scheme in terms of insulation, heat conduction, viscosity stability, oxidation resistance and other aspects, and meets the special needs of hybrid vehicle power and drive system.

[0030] The above only describes the preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A driving fluid for a new energy hybrid vehicle, characterized in that: By weight percentage, it includes 70-85% base oil, 0.8-2.5% conductivity inhibitor, 1-3% nano thermal conductive agent, 4-8% viscosity index improver, 0.1-0.5% ion scavenger, 3-5% extreme pressure anti-wear agent, 0.5-1.5% antioxidant, and 0.001-0.01% antifoaming agent; The base oil is a blend of polyalphaolefins, alkyl naphthalenes, and ester oils in a mass ratio of (4-6):(0.8-1.2):(1.5-2.5). The conductivity inhibitor is composed of a thiadiazole derivative, borodiimizoline, and rare earth organic molybdenum in a mass ratio of (1-1.5):(0.4-0.6):(0.2-0.4). The nano thermal conductive agent consists of alumina nanoparticles coated with a polydopamine-siloxane hybrid layer, with a particle size of 20-50 nm and a hybrid layer thickness of 5-8 nm. Viscosity index improver, which is a poly(N-isopropylacrylamide-styrene block copolymer; Ion scavenger is a porous covalent organic framework (COF) material.

2. The driving fluid for new energy hybrid vehicle power according to claim 1, characterized in that: The polydopamine-siloxane hybrid layer of the nano-thermal conductive agent contains sulfonic acid groups and is bonded to the base oil through a hydrogen bond network, so that the dispersion stability D90 value of the nanoparticles is ≤100nm in the temperature range of -40℃ to 180℃.

3. The driving fluid for new energy hybrid vehicle power according to claim 2, characterized in that: The ion trapping agent is a two-dimensional COF material with imine bonds, a pore size of 1.2-1.8 nm, and a specific surface area ≥800 m². 2 / g, used for selective adsorption of free Cu in oil. 2+ and Fe 3+ ion.

4. The driving fluid for new energy hybrid vehicle power according to claim 3, characterized in that: In the viscosity index improver, the poly(N-isopropylacrylamide-styrene) block copolymer has a molecular weight of 5000-8000 g / mol for the poly(N-isopropylacrylamide) segment and a molecular weight of 3000-5000 g / mol for the styrene segment.

5. The driving fluid for a new energy hybrid vehicle according to claim 4, characterized in that: The alkyl naphthalene in the base oil is diisopropyl naphthalene, with a kinematic viscosity ≤1200 cSt at -50°C, and the ester oil is pentaerythritol ester.

6. The driving fluid for a new energy hybrid vehicle according to claim 5, characterized in that: The extreme pressure anti-wear agent is a mixture of ashless sulfur-phosphorus compound and borate ester in a mass ratio of (2.5-3.5):1, wherein; The sulfur-phosphorus compound is selected from at least one of dialkyl dithioammonium phosphate and tricresyl phosphate; The borate ester is triethanolamine borate ester with a boron content ≥8wt%.

7. The driving fluid for a new energy hybrid vehicle according to claim 6, characterized in that: The antioxidant is a compound of N-phenyl-α-naphthylamine and 2,6-di-tert-butyl-p-cresol in a ratio of (1-1.2):1, and it synergistically reduces the rate of copper catalytic oxidation by more than 40% with rare earth organic molybdenum in the conductivity inhibitor.

8. The driving fluid for a new energy hybrid vehicle according to claim 7, characterized in that: The antifoaming agent is polydimethylsiloxane.

9. A preparation method for preparing the driving fluid for the new energy hybrid vehicle power system as described in claim 8, characterized in that: Specifically, the following steps are included: S1. Base oil pretreatment: Polyalphaolefin, alkylnaphthalene and ester oil are mixed and stirred at 60±5℃ for 30min, and then vacuum dehydrated until the water content is ≤50ppm to obtain base oil. S2. In-situ modification of nano-thermal conductive agent: Alumina nanoparticles and dopamine hydrochloride are added to the base oil obtained in step S1, and ultrasonic treatment is carried out at 40kHz for 1.5-2h under nitrogen protection to simultaneously complete the polymerization of polydopamine-siloxane hybrid layer on the alumina surface. S3, gradient temperature control compound, add conductive inhibitor and extreme pressure anti-wear agent at 40±2℃, stir for 20min, heat to 70±2℃ and add viscosity index improver, stir for 30min, cool to 50±2℃ and add ion scavenger, antioxidant and antifoaming agent, stir for 40min to obtain drive oil; When adding extreme pressure anti-wear agents, first add sulfur-phosphorus compounds, and then add borate esters after 15 minutes.

10. The preparation method according to claim 9, characterized in that: In step S2, the amount of dopamine hydrochloride added is 15-25% of the mass of alumina nanoparticles, and nitrogen gas is introduced throughout the ultrasonic process while controlling the oxygen content to ≤10ppm.

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