Electric vehicle battery cooling liquid composition

Abstract

The invention relates to a cooling liquid composition for a battery of an electric vehicle, and belongs to the technical field of cooling liquid for the battery of the electric vehicle, the cooling liquid composition for the battery of the electric vehicle comprises synthetic base oil and an antioxidant, the mass fraction of the synthetic base oil is 99.0 to 99.8, and the mass fraction of the antioxidant is 1.0 to 0.2. The cooling liquid composition for the electric vehicle has the characteristics of good insulativity, viscosity-temperature property and safety, can be in direct contact with a battery pack, ensures uniform-temperature reliable operation of the battery pack, prolongs the service life of the battery, effectively inhibits safety accidents caused by over-high temperature of the battery in the working process of rapid charging and discharging of the battery pack, and improves the safety of the battery pack. And the cooling liquid has excellent viscosity-temperature property, low temperature environment, good fluidity and high flash point, the kinematic viscosity of the cooling liquid is slightly changed along with the temperature, heat generated by the battery can be quickly transferred, the optimal working temperature of a battery cell is kept, and thermal runaway and thermal spread of the battery can be effectively inhibited.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electric vehicle battery coolant, and particularly relates to an electric vehicle battery coolant composition. BACKGROUND

[0002] In recent years, new energy electric vehicles as a kind of green transportation tool have been vigorously promoted. With the increasing of the battery installation density and energy density of electric vehicles, the heat released by the battery cells in the charging and discharging process is increasing. The heat is not evenly distributed on each battery, so that the battery with more heat generates fast temperature rise. The overheat of the battery pack causes frequent fire and combustion accidents, and consumers are anxious about the safety of electric vehicles, which affects the rapid popularization of electric vehicles. The uneven temperature distribution of the battery pack also causes the capacity of the battery pack to decrease, the charging and discharging efficiency to decrease, and the service life of the battery to shorten.

[0003] With the increasing of the battery installation density and energy density of electric vehicles, the traditional air cooling method cannot meet the heat dissipation requirements of the battery pack of electric vehicles due to the small heat carrying capacity and low thermal conductivity of air, slow cooling response. The existing mineral oil type electric vehicle coolant has small viscosity index, low flash point and small breakdown voltage, which will cause great safety hazards of the mineral oil type electric vehicle coolant when cooling the battery pack. Based on this, an electric vehicle battery coolant composition is proposed. SUMMARY

[0004] The purpose of the present application is to provide an electric vehicle battery coolant composition to solve the above problems.

[0005] The application achieves the above-mentioned purpose by the following technical solutions:

[0006] An electric vehicle battery coolant composition comprises:

[0007] Synthetic base oil and antioxidant;

[0008] The mass fraction of the synthetic base oil is 99.0-99.8, and the mass fraction of the antioxidant is 1.0-0.2.

[0009] As a further optimization scheme of the present application, the synthetic base oil is dimethylsiloxane.

[0010] As a further optimization scheme of the present application, the antioxidant is one or more of 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butyl phenol or alkyl diphenylamine.

[0011] A preparation method of an electric vehicle battery coolant composition comprises the following steps:

[0012] Step 1: Add a certain mass of synthetic base oil and antioxidant to the mixing tank;

[0013] Step 2: Start the stirring vessel and set the mixing temperature to between 60℃ and 70℃;

[0014] Step 3: Start the mixing tank to mix the synthetic base oil and antioxidant. Stir until clear and transparent, then cool to room temperature.

[0015] Step 4: Discharge the mixed synthetic base oil and antioxidant, cooled to room temperature, into a filter to obtain the electric vehicle coolant composition.

[0016] As a further optimization of the present invention, the prepared electric vehicle coolant composition has a kinematic viscosity of 35 when the ambient temperature reaches 40°C. Up to 40 .

[0017] As a further optimization of the present invention, the breakdown voltage of the prepared electric vehicle coolant composition is greater than 30kV.

[0018] As a further optimization of the present invention, the viscosity index of the prepared electric vehicle coolant composition is greater than 400.

[0019] As a further optimization of the present invention, the prepared electric vehicle coolant composition has an open flash point greater than 300°C.

[0020] The beneficial effects of this invention are as follows:

[0021] The electric vehicle coolant composition proposed in this invention has excellent insulation, viscosity-temperature characteristics, and safety. It can directly contact the battery pack, ensuring the battery pack operates reliably with uniform temperature during rapid charging and discharging, extending battery life, effectively suppressing safety accidents caused by excessive battery temperature, and reducing the safety risks of electric vehicles. It has excellent viscosity-temperature characteristics, with minimal change in kinematic viscosity with temperature. In low-temperature environments, the coolant has good fluidity and a high flash point, which can quickly transfer the heat generated by the battery, maintaining the optimal operating temperature of the battery cells and effectively suppressing battery thermal runaway and heat propagation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the preparation process of the electric vehicle battery coolant composition of the present invention. Detailed Implementation

[0023] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0024] Example: An electric vehicle battery coolant composition, comprising: a synthetic base oil and an antioxidant; the synthetic base oil comprises 99.0-99.8 parts by weight, and the antioxidant comprises 1.0-0.2 parts by weight; the synthetic base oil is dimethylsiloxane; the antioxidant is one or more of 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol, or alkyl diphenylamine.

[0025] like Figure 1 As shown, a method for preparing an electric vehicle battery coolant composition includes the following steps:

[0026] Step 1: Add a certain mass of synthetic base oil and antioxidant to the mixing tank;

[0027] Step 2: Start the stirring vessel and set the mixing temperature to between 60℃ and 70℃;

[0028] Step 3: Start the mixing tank to mix the synthetic base oil and antioxidant. After stirring until clear and transparent, cool to room temperature (room temperature generally refers to a temperature between 15°C and 25°C, usually defined as 25°C).

[0029] Step 4: Discharge the mixed synthetic base oil and antioxidant, cooled to room temperature, into a filter to obtain the electric vehicle coolant composition.

[0030] The prepared electric vehicle coolant composition has a kinematic viscosity of 35 at an ambient temperature of 40°C. Up to 40 .

[0031] The prepared electric vehicle coolant composition has a breakdown voltage greater than 30kV, a viscosity index greater than 400, and an open flash point greater than 300℃.

[0032] Example 1:

[0033] Step 1: Add 99.0-99.8 parts by weight of dimethylsiloxane and 1.0-0.2 parts by weight of 2,6-di-tert-butyl-p-cresol to the stirred tank;

[0034] Step 2: Start the stirring vessel and set the mixing temperature to 60℃;

[0035] Step 3: Start the mixing tank to mix the synthetic base oil and antioxidant. Stir until clear and transparent, then cool to room temperature.

[0036] Step 4: Discharge the mixed synthetic base oil and antioxidant, cooled to room temperature, into a filter to obtain the electric vehicle coolant composition.

[0037] Example 2:

[0038] Step 1: Add 99.0-99.8 parts by weight of dimethylsiloxane and 1.0-0.2 parts by weight of 2,6-di-tert-butylphenol and alkyl diphenylamine to the stirred tank;

[0039] Step 2: Start the mixing vessel and set the mixing temperature to 65℃;

[0040] Step 3: Start the mixing tank to mix the synthetic base oil and antioxidant. Stir until clear and transparent, then cool to room temperature.

[0041] Step 4: Discharge the mixed synthetic base oil and antioxidant, cooled to room temperature, into a filter to obtain the electric vehicle coolant composition.

[0042] Example 3:

[0043] Step 1: Add 99.0-99.8 parts by weight of dimethylsiloxane and 1.0-0.2 parts by weight of 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol or alkyl diphenylamine to the stirred tank;

[0044] Step 2: Start the mixing vessel and set the mixing temperature to 70℃;

[0045] Step 3: Start the mixing tank to mix the synthetic base oil and antioxidant. Stir until clear and transparent, then cool to room temperature.

[0046] Step 4: Discharge the mixed synthetic base oil and antioxidant, cooled to room temperature, into a filter to obtain the electric vehicle coolant composition.

[0047] Example 4 (for comparison):

[0048] Step 1: Add 99.0-99.8 parts by weight of mineral base oil and 1.0-0.2 parts by weight of antioxidant to the mixing tank;

[0049] Step 2: Start the mixing vessel and set the mixing temperature to 65℃;

[0050] Step 3: Start the mixing tank to mix the synthetic base oil and antioxidant. Stir until clear and transparent, then cool to room temperature.

[0051] Step 4: Discharge the mixed synthetic base oil and antioxidant, cooled to room temperature, into a filter to obtain mineral oil-based electric vehicle coolant.

[0052] The electric vehicle coolant compositions of Examples 1 to 3 and the comparative example, along with the mineral oil-based electric vehicle coolant of the comparative example, were tested for kinematic viscosity, viscosity index, specific heat, flash point, and breakdown voltage. The performance comparison is shown in Table 1. As can be seen from Table 1, the electric vehicle coolant composition of Example 1 prepared using the scheme of the present invention achieves good results in terms of kinematic viscosity, viscosity index, specific heat, flash point, and breakdown voltage. The mineral oil-based coolant in the comparative example has a low viscosity index, low flash point, and low breakdown voltage, reflecting the advantages of the synthetic base oil used in the present invention, such as good viscosity-temperature characteristics and high safety, thus meeting the requirements of stable properties and high safety for electric vehicle coolants.

[0053] In summary, the present invention provides a coolant composition for electric vehicle battery packs, wherein the synthetic base oil is dimethylsiloxane and functional additives are added. The synthetic coolant has good insulation properties, excellent viscosity-temperature characteristics, and a high flash point, ensuring the uniform and reliable operation of electric vehicle battery packs and reducing safety hazards.

[0054] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

[0055] Table 1

[0056]

[0057] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A coolant composition for an electric vehicle battery, characterized in that, include: Synthetic base oils and antioxidants; The synthetic base oil has a mass fraction of 99.0-99.8, and the antioxidant has a mass fraction of 1.0-0.

2.

2. The electric vehicle battery coolant composition according to claim 1, characterized in that: The synthetic base oil is dimethylsiloxane.

3. The electric vehicle battery coolant composition according to claim 1, characterized in that: The antioxidant is one or more of 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol, or alkyl diphenylamine.

4. A method for preparing an electric vehicle battery coolant composition, used to prepare the electric vehicle battery coolant composition according to claim 1, characterized in that, Includes the following steps: Step 1: Add a certain mass of synthetic base oil and antioxidant to the mixing tank; Step 2: Start the stirring vessel and set the mixing temperature to between 60℃ and 70℃; Step 3: Start the mixing tank to mix the synthetic base oil and antioxidant. Stir until clear and transparent, then cool to room temperature. Step 4: Discharge the mixed synthetic base oil and antioxidant, cooled to room temperature, into a filter to obtain the electric vehicle coolant composition.

5. The method for preparing an electric vehicle battery coolant composition according to claim 4, characterized in that: The prepared electric vehicle coolant composition has a kinematic viscosity of 35 at an ambient temperature of 40°C. Up to 40 .

6. The method for preparing an electric vehicle battery coolant composition according to claim 4, characterized in that: The breakdown voltage of the prepared electric vehicle coolant composition is greater than 30kV.

7. The method for preparing an electric vehicle battery coolant composition according to claim 4, characterized in that: The viscosity index of the prepared electric vehicle coolant composition is greater than 400.

8. The method for preparing an electric vehicle battery coolant composition according to claim 4, characterized in that: The prepared electric vehicle coolant composition has an open flash point greater than 300°C.

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