Thermal management liquid composition of electric vehicle battery as well as preparation method and application of thermal management liquid composition

Abstract

The invention belongs to the technical field of electric vehicle cooling liquid, and particularly relates to a thermal management liquid composition of an electric vehicle battery as well as a preparation method and application of the thermal management liquid composition. The heat management liquid composition is prepared from the following raw materials in parts by weight: 90 to 110 parts of basic liquid, 0.3 to 0.8 part of a preservative, 0.001 to 0.008 part of an anti-foaming agent and 0.0001 to 0.0004 part of a coloring agent. The conductivity of the electric vehicle battery thermal management fluid is less than or equal to 100 uS / cm, and the electric vehicle battery thermal management fluid has excellent protection capability on copper, steel and aluminum alloy and good compatibility effect with internal system rubber parts.

Description

Technical Field

[0001] This invention belongs to the field of electric vehicle coolant technology, specifically relating to a thermal management fluid composition for electric vehicle batteries, its preparation method, and its application. Background Technology

[0002] The rapid development of the automotive industry has driven the research and production of coolants. Engine coolant is the circulating medium in the engine cooling system. Its heat transfer properties, high boiling point, and low freezing point effectively inhibit boiling at high temperatures and freezing at low temperatures, thus protecting the engine. The cooling system of an electric motor in an electric vehicle typically removes about 95% of the heat generated by the powertrain. Battery thermal management systems have high power density, and their temperature has a significant impact on the energy storage, durability, lifespan, and efficiency of the battery pack.

[0003] Traditional coolants typically have a conductivity of 2000-5000 μS / cm. High conductivity coolants, if leaking, can negatively impact a vehicle's electronic systems, such as increasing the risk of electrical leakage and affecting the normal operation of electronic components. Low conductivity coolants are therefore crucial for ensuring the safe and stable operation of electric vehicle electrical systems.

[0004] Traditional coolants typically use ethylene glycol and deionized water as base fluids, supplemented with inorganic or organic additives. However, traditional ethylene glycol-water and propylene glycol-water coolants cannot meet the requirements of electric vehicle cooling systems. The main reasons are: 1. Electric vehicle cooling systems use various types of aluminum, which differ from the aluminum used in traditional gasoline vehicles; 2. Electric vehicle cooling systems require coolants with low electrical conductivity (typically less than 5 μS / cm). To address this issue, low-conductivity coolants have been developed abroad, with freezing points reaching -36°C. However, the conductivity of these coolants increases with temperature. Under high-temperature conditions (e.g., 50°C and 88°C), the conductivity reaches 2.4 and 5.2 μS / cm respectively, failing to meet the requirements for extremely low conductivity, and they do not provide corrosion protection for metals such as steel and iron.

[0005] Chinese invention patent application CN117447973A discloses a coolant for electric vehicles and its preparation method, belonging to the field of coolant technology. The preparation method includes steps of preparing additives, preparing stabilizers, activating alumina, and mixing. The stabilizer preparation step involves mixing sodium methylsilicate and gum arabic, adding soybean lecithin, and subjecting the mixture to low-temperature, high-pressure treatment for 25-29 minutes at a controlled temperature of -2.2 to -2.0°C and a pressure of 3.3-3.5 MPa. After the low-temperature, high-pressure treatment, oleic acid and sodium carboxymethyl cellulose are added for high-temperature, low-pressure treatment. The temperature is increased to 40-44°C at a rate of 0.1-0.3°C / min, and the pressure is reduced to 0.18-0.22 MPa for 26-30 minutes. After the high-temperature, low-pressure treatment, the stabilizer is obtained. The coolant prepared by this invention has low conductivity, excellent corrosion resistance, and good stability. However, it requires a large amount of raw materials and has a complex preparation process.

[0006] Therefore, there is a need to develop a low-conductivity electric vehicle battery thermal management fluid that is easy to prepare, has good corrosion resistance to metals in the cooling system, and can ensure the safe operation of electric vehicles. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a thermal management fluid composition for electric vehicle batteries, its preparation method, and its application.

[0008] This invention is achieved through the following technical solutions:

[0009] A thermal management fluid composition for an electric vehicle battery, wherein the raw materials of the thermal management fluid composition include, by weight, 90-110 parts of base liquid, 0.3-0.8 parts of preservative, 0.001-0.008 parts of antifoaming agent and 0.0001-0.0004 parts of dye.

[0010] Preferably, the base solution is a mixture of deionized water and antifreeze, wherein the antifreeze is a monohydric alcohol or a dihydric alcohol.

[0011] More preferably, the antifreeze is ethylene glycol or propylene glycol.

[0012] More preferably, the mass ratio of the deionized water to the antifreeze is 1:0.8-1.2.

[0013] Preferably, the preservative is selected from one or more of azole compounds, dicarboxylic acids, amide compounds, and ketone compounds.

[0014] More preferably, the azole compound is selected from one or two of benzotriazole, methylbenzotriazole, ethylbenzotriazole, and azole derivatives.

[0015] More preferably, the dicarboxylic acid is selected from one or more of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, and dodecanoic acid.

[0016] More preferably, the amide compound is selected from one or more of formamide, acetamide, caprolactam, and benzamide.

[0017] More preferably, the ketone compound is selected from one or two of hexaalkyl-2,4-dione, benzylethyl dimethyl ketone, 1-phenylpentane-2,3-dione, hepta-2-one, and 2-chlorocyclohexane-2,5-diene-1,4-dione.

[0018] More preferably, the antifoaming agent is selected from one or more of LZ5674, P21 and MS550.

[0019] More preferably, the staining agent is selected from one or more of rose red, fluorescein, and rhodamine B.

[0020] Preferably, the electrical conductivity of the thermal management fluid composition is ≤100 μS / cm.

[0021] The present invention also relates to a method for preparing the above-mentioned thermal management fluid composition, comprising the following steps: mixing a base liquid water and ethylene glycol, adding a preservative, and finally adding an antifoaming agent and a dyeing agent to obtain the thermal management fluid composition.

[0022] The present invention also relates to the application of the above-mentioned thermal management fluid composition in the preparation of electric vehicle coolant.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The electric vehicle battery thermal management fluid of the present invention has a conductivity of ≤100uS / cm and has excellent protection capabilities for copper, steel and aluminum alloys.

[0025] (2) By adding a specific corrosion inhibitor system, the present invention has both low electrical conductivity and excellent corrosion protection for aluminum alloys, steel and copper. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are not intended to limit the present invention, but only to illustrate the present invention. Unless otherwise specified, the experimental methods used in the following embodiments are generally performed under conventional conditions. Unless otherwise specified, the materials and reagents used in the following embodiments are commercially available.

[0027] Antifoaming agent LZ5674 was purchased from Lubrizol Corporation; antifoaming agent P21 was purchased from Beijing Zehua Chemical Engineering Co., Ltd.; antifoaming agent MS550 was purchased from Mengqingxin Additives Trading (Shanghai) Co., Ltd.

[0028] Example 1

[0029] A thermal management fluid composition for an electric vehicle battery, the raw materials and the mass fractions of the additives are shown in Table 1.

[0030] Mix the raw materials in Table 1 evenly to obtain the heat management fluid composition.

[0031] Table 1 Raw materials and their mass fractions

[0032]

[0033] Example 2

[0034] A thermal management fluid composition for an electric vehicle battery, the raw materials and the mass fractions of the additives are shown in Table 2.

[0035] Mix the raw materials in Table 2 evenly to obtain the heat management fluid composition.

[0036] Table 2 Raw materials and mass fractions

[0037]

[0038]

[0039] Example 3

[0040] A thermal management fluid composition for an electric vehicle battery, the raw materials and the mass fractions of the additives are shown in Table 3.

[0041] Mix the raw materials in Table 3 evenly to obtain the heat management fluid composition.

[0042] Table 3 Raw materials and parts by weight

[0043]

[0044] Comparative Examples 1-3

[0045] Comparative Example 1 is a commercially available low-conductivity electric vehicle coolant product (50% by mass). The raw materials and mass fractions of the thermal management fluid compositions of Comparative Examples 1-3 are shown in Table 4.

[0046] Table 4 Raw materials and parts by weight

[0047]

[0048]

[0049] Comparative Examples 4-7

[0050] Comparative Examples 4-7 differ from Example 1 only in the mass fractions of methylbenzotriazole, benzyl ethyl dimethyl ketone, and acetamide. See Table 5 for details.

[0051] Table 5 Raw materials and their mass fractions

[0052]

[0053] Effect test

[0054] The conductivity test method is as follows: The conductivity is tested according to Appendix A of GB 29743.2, Test Method for Conductivity of Tram Coolant.

[0055] Metal corrosion testing shall be performed in accordance with SH / T 0085, at a temperature of 80℃ for 1500 hours.

[0056] The test results of Examples 1-3 and Comparative Examples 1-7 are shown in Tables 6 and 7.

[0057] Table 6 Test results of Examples 1-3 and Comparative Examples 1-3

[0058]

[0059]

[0060] Table 7 shows the test results of Comparative Examples 4-7.

[0061]

[0062] As shown in Tables 6-7, the composition of the present invention provides stronger protection for various metal materials in the cooling system.

[0063] The above detailed description is a specific description of one of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included within the scope of the technical solution of the present invention.

Claims

1. A thermal management fluid composition for an electric vehicle battery, characterized by, The raw materials of the thermal management liquid composition include, by weight fraction, 90-110 parts of a base liquid, 0.3-0.8 parts of a preservative, 0.001-0.008 parts of an anti-foaming agent, and 0.0001-0.0004 parts of a dyeing agent.

2. The thermal management fluid composition of claim 1, wherein, The base liquid is a mixed solution of deionized water and an anti-freezing agent, and the anti-freezing agent is a mono-alcohol or a di-alcohol.

3. The thermal management fluid composition of claim 2, wherein, The anti-freezing agent is ethylene glycol or propylene glycol.

4. The thermal management fluid composition of claim 2, wherein, The mass ratio of the deionized water to the anti-freezing agent is 1:0.8-1.

2.

5. The thermal management fluid composition of claim 1, wherein, The preservative is a mixture of an azole compound, a dicarboxylic acid, an amide compound, and a ketone compound.

6. The thermal management fluid composition of claim 5, wherein, The mass ratio of the azole compound, the dicarboxylic acid, the amide compound, and the ketone compound is 1-5:0.1-0.5:0.2-2.5:1-2.

7. The thermal management fluid composition of claim 5, wherein, The azole compound is selected from one or two of benzotriazole, methylbenzotriazole, ethylbenzotriazole, and azole derivatives.

8. The thermal management fluid composition of claim 5, wherein, The dicarboxylic acid is selected from one or more of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid.

9. The thermal management fluid composition of claim 5, wherein, The amide compound is selected from one or more of formamide, acetamide, caprolactam, and benzamide.

10. The thermal management fluid composition of claim 5, wherein, The ketone compound is selected from one or two of hexan-2,4-dione, benzyl ethyl dimethyl ketone, 1-phenylpentan-2,3-dione, heptan-2-one, and 2-chlorocyclohexa-2,5-diene-1,4-dione.

11. The thermal management fluid composition of claim 1, wherein, The anti-foaming agent is selected from one or more of LZ5674, P21, and MS550.

12. The thermal management fluid composition of claim 1, wherein, The dyeing agent is selected from one or more of rose Bengal, fluorescein, and rhodamine B.

13. The thermal management fluid composition of any one of claims 1-12, wherein, The thermal management liquid composition has an electrical conductivity of ≤100 uS / cm.

14. A method of preparing the heat management fluid composition of any one of claims 1-13, characterized in that, The method comprises the following steps: mixing the base liquid water and ethylene glycol, adding the preservative, and finally adding the anti-foaming agent and the dyeing agent to obtain the thermal management liquid composition.

15. Use of the thermal management liquid composition of any one of claims 1-13 in the preparation of a cooling liquid for an electric vehicle.

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