Immersed cooling liquid and preparation method thereof, battery device and power utilization device

Abstract

The invention provides an immersed cooling liquid, a preparation method thereof, a battery device and an electric device. The immersed cooling liquid comprises the following components in parts by weight: 40-50 parts of poly-alpha-olefin synthetic base oil PAO 2, 50-60 parts of poly-alpha-olefin synthetic base oil PAO 4, 0.1-0.4 part of a pour point depressant and 0.1-0.9 part of an antioxidant. The immersed cooling liquid provided by the invention has relatively good fluidity, stability and heat transfer performance.

Description

Technical Field

[0001] The present application relates to the technical field of battery thermal management, and in particular to an immersion coolant and a preparation method thereof, a battery device and an electrical device. Background Art

[0002] In recent years, as the application scope of secondary batteries becomes wider and wider, secondary batteries are widely used in energy storage power supply systems such as hydropower, thermal power, wind power and solar power stations, as well as in many fields such as electric tools, electric bicycles, electric motorcycles and electric vehicles.

[0003] Secondary batteries generate a lot of heat during the charging and discharging process. For example, the temperature of electric vehicle batteries can rise rapidly during fast charging or high-load discharge. By setting up a battery thermal management device, the coolant in the thermal management device can absorb the large amount of heat generated by the battery and transfer the heat through the circulation system, thereby effectively controlling the battery temperature. By circulating the coolant in the battery pack, the temperature uniformity of various parts of the battery can be improved, alleviating local overheating or overcooling in the battery pack, better protecting the battery and extending the battery life.

[0004] Immersion cooling technology is a battery thermal management method that directly immerses the battery in a coolant. It has the advantages of simple structure, rapid cooling and good temperature uniformity, and can effectively reduce the battery temperature and improve the temperature uniformity of the battery pack. The coolant used in immersion cooling technology, namely the immersion coolant, needs to meet certain selection criteria, including good electrical insulation, non-flammability, appropriate operating temperature range, long service life, good material compatibility, low mass, low viscosity and low corrosiveness.

[0005] With the increasing application of secondary batteries, higher requirements are placed on the performance of immersion coolants in battery thermal management devices. Traditional immersion coolants still need to be further improved in terms of fluidity, stability and heat transfer performance. Therefore, developing an immersion coolant with good fluidity, stability and heat transfer performance has become one of the important research directions in this field. Summary of the invention

[0006] The present application is made in view of the above-mentioned problems, and one of its purposes is to provide an immersion coolant and a preparation method thereof, a battery device and an electrical device, wherein the immersion coolant has good fluidity, stability and heat transfer performance.

[0007] In order to achieve the above object, the first aspect of the present application provides an immersion cooling liquid, which comprises the following components by weight:

[0008] 40 to 50 parts of polyalphaolefin synthetic base oil PAO 2, 50 to 60 parts of polyalphaolefin synthetic base oil PAO 4, 0.1 to 0.4 parts of pour point depressant and 0.1 to 0.9 parts of antioxidant.

[0009] By using polyalphaolefin synthetic base oil PAO 2 and polyalphaolefin synthetic base oil PAO 4 as the base oil of immersion coolant, and compounding with pour point depressant and antioxidant, the immersion coolant has good fluidity, good stability and heat transfer performance at the same time through the mutual cooperation of each component at a specific dosage. Among them, PAO 2 and PAO 4 are both polyalphaolefin synthetic base oils, which have better stability than ester base oils; and PAO 2 has low viscosity and good fluidity. When the battery is running at low temperature, it can flow quickly inside the battery pack and quickly take away the heat generated by the battery; while PAO 4 has a relatively high viscosity and can maintain a stable heat transfer efficiency under high temperature battery operation conditions, ensuring that the coolant can still maintain good thermal conductivity at higher temperatures. The addition of a specific amount of antioxidant is more conducive to improving the stability of PAO 2 and PAO 4, thereby improving the stability of the immersion coolant; the addition of a specific amount of pour point depressant is conducive to reducing the pour point of the immersion coolant, so that the immersion coolant can still maintain good fluidity at a lower temperature. By compounding PAO 2, PAO4, pour point depressant and antioxidant in a specific proportion, the coolant can have better fluidity, stability and heat transfer performance, and can better adapt to battery operating conditions at different temperatures.

[0010] In any embodiment, the following components are included by weight: 45 to 49 parts of polyalphaolefin synthetic base oil PAO 2, 50 to 54 parts of polyalphaolefin synthetic base oil PAO 4, 0.1 to 0.4 parts of pour point depressant and 0.1 to 0.9 parts of antioxidant. This is more conducive to improving the fluidity and heat transfer performance of the immersion coolant.

[0011] In any embodiment, the kinematic viscosity of the poly-alpha-olefin synthetic base oil PAO 2 at 100° C. is 1 mm 2 / s~3mm 2 / s, and the viscosity index of the poly-alpha-olefin synthetic base oil PAO 2 is greater than or equal to 90. This is conducive to enabling the immersion coolant to adapt to a wider temperature range.

[0012] In any embodiment, the kinematic viscosity of the polyalphaolefin synthetic base oil PAO 4 at 100° C. is 3.6 mm 2 / s~4.9mm 2 / s, and the viscosity index of the poly-alpha-olefin synthetic base oil PAO 4 is greater than or equal to 120. This is conducive to enabling the immersion coolant to adapt to a wider temperature range.

[0013] In any embodiment, the antioxidant includes one or more of a hindered phenol antioxidant and an ester antioxidant. Thus, using the above-mentioned antioxidants is beneficial to improving the stability of the immersion cooling liquid.

[0014] In any embodiment, the hindered phenol antioxidant includes one or more of Irganox L107, 2,6-di-tert-butyl-p-cresol, Irganox L39 and octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate. Using the above-mentioned types of antioxidants as hindered phenol antioxidants can achieve good antioxidant effects.

[0015] In any embodiment, the ester antioxidant includes one or more of dilauryl thiodipropionate, distearyl thiodipropionate, triphenyl phosphite, tris(nonylphenyl) phosphite and pentaerythritol tetrakis(3-dodecyloxythiopropionate). Using the above-mentioned antioxidants as ester antioxidants can achieve good antioxidant effects.

[0016] In any embodiment, the antioxidant includes a hindered phenol antioxidant and an ester antioxidant, and the weight ratio of the hindered phenol antioxidant to the ester antioxidant is 3 to 8: 2. In this way, by compounding the above two types of antioxidants according to a specific ratio, the oxidation reaction process can be blocked from different links, thereby synergistically improving the antioxidant performance and stability of the immersion coolant.

[0017] In any embodiment, the pour point depressant includes one or more of polymethacrylate pour point depressants and modified products thereof. The use of the above pour point depressants is beneficial to lowering the pour point of the immersion coolant and improving the low temperature fluidity of the immersion coolant.

[0018] Without limitation, the modified polymethacrylate type pour point depressants include long chain alkyl modified polymethacrylate pour point depressants, polar group-containing modified polymethacrylate pour point depressants, copolymer modified polymethacrylate pour point depressants, high molecular weight modified polymethacrylate pour point depressants, and the like.

[0019] In any embodiment, 0.05 to 0.3 parts of defoaming agent are also included by weight, which is helpful to reduce the amount of bubbles formed during the use of the coolant, thereby alleviating the corrosion effect on the surface metal.

[0020] In any embodiment, the defoaming agent includes one or more of a nonionic surfactant, an aliphatic defoaming agent and an aromatic hydrocarbon defoaming agent. In this way, the amount of bubbles formed during the use of the coolant can be effectively reduced, and the corrosion of the surface metal can be alleviated.

[0021] A second aspect of the present application provides a method for preparing an immersion cooling liquid, comprising the following steps:

[0022] Providing raw materials according to the composition of the immersion cooling liquid of the first aspect of the present application;

[0023] The raw materials are stirred and mixed evenly to obtain the immersion cooling liquid.

[0024] Thus, the preparation method has simple process and low production cost.

[0025] In any embodiment, the stirring and mixing temperature is 45°C to 65°C, the stirring and mixing speed is 1000r / min to 2000r / min, and the stirring and mixing time is 2h to 3h. This is conducive to forming an immersion coolant with uniform composition and stable performance.

[0026] In any embodiment, after the raw materials are stirred and mixed evenly, the process further includes the step of allowing the mixed solution to stand and cool for 2 to 3 hours and then filtering to obtain the filtrate.

[0027] A third aspect of the present application provides a battery device, comprising a housing, a battery cell, and the immersion coolant of the first aspect of the present application, wherein the battery cell and the immersion coolant are accommodated in the housing, and the battery cell is at least partially immersed in the immersion coolant.

[0028] A fourth aspect of the present application provides an electrical device, comprising the battery device of the third aspect of the present application. DETAILED DESCRIPTION

[0029] The following describes in detail the implementation of the immersion coolant and its preparation method, battery device and electrical device of the present application. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the following description is provided for those skilled in the art to fully understand the present application and is not intended to limit the subject matter described in the claims.

[0030] The "range" disclosed in the present application can be limited in the form of a lower limit and an upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The range limited in this way can be including or excluding end values, and any end value can be included or not included independently, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a specific parameter, it is understood that the range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are also listed, the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise specified, the numerical range "a to b" represents the abbreviation of any real number combination between a and b, wherein a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to listing the parameter as, for example, integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For example, when a parameter is expressed as an integer selected from "2-10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9 and 10.

[0031] In the present application, "plurality", "multiple" and the like, unless otherwise specified, refer to a number greater than or equal to 2. For example, "one or more" means one or greater than or equal to two.

[0032] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0033] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment or implementation of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments. The "implementation methods" mentioned herein have a similar understanding.

[0034] Those skilled in the art will appreciate that, in the methods of each embodiment or example, the order in which each step is written does not mean a strict order of execution and does not constitute any limitation on the implementation process, and the detailed order of execution of each step should be determined by its function and possible internal logic. If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or steps (b) and (a) performed sequentially. For example, the method may also include step (c), indicating that step (c) can be added to the method in any order, for example, the method may include steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0035] In the present application, in the open technical features or technical solutions described by the words "contain", "include", "comprise", etc., unless otherwise specified, additional members other than the listed members are not excluded, and it can be regarded as providing both closed features or solutions consisting of the listed members and open features or solutions including additional members in addition to the listed members. For example, A includes a1, a2 and a3. Unless otherwise specified, it may also include other members or may not include additional members. It can be regarded as providing both the feature or solution of "A consists of a1, a2 and a3" and the feature or solution of "A not only includes a1, a2 and a3, but also includes other members". In the present application, unless otherwise specified, A (such as B) means that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0036] In this application, "optionally", "optional", and "optional" mean optional, that is, any one of the two parallel schemes of "yes" or "no". If there are multiple "options" in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "option" is independent.

[0037] At present, with the increasing application of secondary batteries, higher requirements are also put forward for the performance of immersion coolants in battery thermal management devices. Traditional immersion coolants still need to be further improved in terms of fluidity, stability and heat transfer performance. In this regard, the present application provides an immersion coolant, which has good fluidity, good stability and heat transfer performance, and can better meet the performance requirements of battery thermal management devices for coolants.

[0038] In one embodiment of the present application, an immersion coolant is provided, which comprises the following components by weight: 40 to 50 parts of polyalphaolefin synthetic base oil PAO 2, 50 to 60 parts of polyalphaolefin synthetic base oil PAO 4, 0.1 to 0.4 parts of pour point depressant and 0.1 to 0.9 parts of antioxidant.

[0039] The above-mentioned immersion coolant of the present application adopts 40 to 50 parts of polyalphaolefin synthetic base oil PAO 2 and 50 to 60 parts of polyalphaolefin synthetic base oil PAO 4 as the base oil of the immersion coolant, and is compounded with 0.1 to 0.4 parts of pour point depressant and 0.1 to 0.9 parts of antioxidant. Through the mutual cooperation between the components, the immersion coolant has good fluidity, good stability and heat transfer performance. Specifically, PAO 2 and PAO 4 are both polyalphaolefin synthetic base oils, which have better stability than ester base oils; and PAO 2 has low viscosity and good fluidity. When the battery is running at low temperature, it can flow quickly inside the battery pack and quickly take away the heat generated by the battery; while PAO 4 has a relatively high viscosity, and can maintain a stable heat transfer efficiency under the high temperature operation condition of the battery, ensuring that the coolant can still maintain good thermal conductivity at higher temperatures. The addition of a specific amount of antioxidant is more conducive to improving the stability of PAO 2 and PAO 4, thereby improving the stability of the immersion coolant; the addition of a specific amount of pour point depressant is conducive to lowering the pour point of the immersion coolant, so that the immersion coolant can still maintain good fluidity at a lower temperature. By compounding PAO 2, PAO 4, pour point depressant and antioxidant in a specific ratio, the coolant can have better fluidity, stability and heat transfer performance, and can better adapt to battery operating conditions at different temperatures.

[0040] In addition, compared with traditional fluorinated liquid immersion coolants, the immersion coolant of the present application has lower cost, is less difficult to recycle and reuse, has less pollution to the environment, has a simpler preparation process, and has a higher cost-effectiveness.

[0041] It should be noted that PAO 2 is a specific grade of polyalphaolefin synthetic base oil. The "PAO" in PAO 2 stands for polyalphaolefin, and the "2" represents that the central value of the kinematic viscosity of the base oil at 40°C is about 2 mm 2 / s. Similarly, polyalphaolefin synthetic base oil PAO 4 is a specific grade of polyalphaolefin synthetic base oil. The "4" in PAO4 represents that the central value of the kinematic viscosity of the base oil at 40°C is about 4mm 2 / s.

[0042] It can be understood that the amount of polyalphaolefin synthetic base oil PAO 2 in the immersion coolant can be 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 ​​parts, 49 parts, 50 parts and any value within the range formed by any two of the above values; the amount of polyalphaolefin synthetic base oil PAO 4 can be 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts and any value within the range formed by any two of the above values; the amount of antioxidant can be 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts and any value within the range formed by any two of the above values. The amount of the pour point depressant may be 0.1 part, 0.125 part, 0.15 part, 0.175 part, 0.2 part, 0.225 part, 0.25 part, 0.275 part, 0.3 part, 0.325 part, 0.35 part, 0.375 part, 0.4 part, and any value within the range formed by any two of the above values.

[0043] In some of the embodiments, the total weight fractions of the poly-alpha-olefin synthetic base oil PAO 2, the poly-alpha-olefin synthetic base oil PAO 4, the pour point depressant and the antioxidant in the immersion coolant is 100 parts.

[0044] In some embodiments, the immersion coolant includes the following components by weight: 45 to 49 parts of polyalphaolefin synthetic base oil PAO 2, 50 to 54 parts of polyalphaolefin synthetic base oil PAO 4, 0.1 to 0.4 parts of pour point depressant, and 0.1 to 0.9 parts of antioxidant. Thus, by compounding the above-mentioned parts by weight of polyalphaolefin synthetic base oil PAO 2, polyalphaolefin synthetic base oil PAO 4 and antioxidant, the immersion coolant is advantageously provided with better fluidity and heat transfer performance.

[0045] In some of the embodiments, the kinematic viscosity of the polyalphaolefin synthetic base oil PAO 2 at 100° C. is 1 mm 2 / s~3mm 2 / s, the viscosity index of the polyalphaolefin synthetic base oil PAO 2 is greater than or equal to 90, and optionally, the viscosity index is greater than or equal to 120. In this way, the polyalphaolefin synthetic base oil PAO 2 has a lower kinematic viscosity, and it can still maintain good fluidity in a low temperature environment; the polyalphaolefin synthetic base oil PAO 2 has a larger viscosity index and excellent viscosity-temperature performance, so that the immersion coolant can adapt to a wider temperature range.

[0046] It should be noted that kinematic viscosity refers to the time it takes for a certain volume of liquid to flow through a calibrated glass capillary viscometer under the action of gravity at a constant temperature. Kinematic viscosity is an important indicator for measuring the fluidity of a liquid. It reflects the internal friction generated by the relative movement between molecules in the base oil under the action of gravity. The viscosity index is an agreed value that indicates the temperature-dependent viscosity characteristics of the base oil. Generally, the higher the viscosity index, the smaller the viscosity of the base oil changes with temperature, that is, the more stable the viscosity can be maintained at different temperatures.

[0047] It is understood that the kinematic viscosity of polyalphaolefin synthetic base oil PAO 2 at 100°C can be 1 mm 2 / s、1.1mm 2 / s、1.2mm 2 / s、1.3mm 2 / s, 1.4mm 2 / s、1.5mm 2 / s, 1.6mm 2 / s, 1.7mm 2 / s、1.8mm 2 / s, 1.9mm 2 / s, 2.0mm 2 / s, 2.1mm 2 / s, 2.2mm 2 / s, 2.3mm 2 / s, 2.4mm 2 / s, 2.5mm 2 / s, 2.6mm 2 / s, 2.7mm 2 / s, 2.8mm 2 / s, 2.9mm 2 / s、3mm 2 / s and any value within the range formed by any two of the above values.

[0048] In some of the embodiments, the kinematic viscosity of the polyalphaolefin synthetic base oil PAO 4 at 100° C. is 3.6 mm 2 / s~4.9mm 2 / s, the viscosity index of the polyalpha-olefin synthetic base oil PAO 4 is greater than or equal to 120, and optionally, the viscosity index is greater than or equal to 130. In this way, the polyalpha-olefin synthetic base oil PAO 4 has a higher kinematic viscosity than the polyalpha-olefin synthetic base oil PAO 2, and compounding it with the polyalpha-olefin synthetic base oil PAO 2 is beneficial to improving the high temperature performance and stability of the immersion coolant. The viscosity index of the polyalpha-olefin synthetic base oil PAO 4 is relatively large, which is beneficial to prevent the viscosity of the immersion coolant from increasing excessively in a low temperature environment and still maintain good fluidity; and its viscosity will not drop significantly due to the increase in temperature, which is beneficial to the immersion coolant having a wider operating temperature range.

[0049] It is understood that the kinematic viscosity of polyalphaolefin synthetic base oil PAO 4 at 100°C can be 3.6 mm 2 / s, 3.7mm 2 / s, 3.8mm 2 / s, 3.9mm 2 / s, 4.0mm 2 / s, 4.1mm 2 / s、4.2mm 2 / s, 4.3mm 2 / s, 4.4mm 2 / s, 4.5mm 2 / s, 4.6mm 2 / s, 4.7mm 2 / s、4.8mm 2 / s, 4.9mm 2 / s and any value within the range formed by any two of the above values.

[0050] In some embodiments, the antioxidant includes a hindered phenol antioxidant and an ester antioxidant. Thus, a composite antioxidant is formed by compounding the hindered phenol antioxidant and the ester antioxidant, wherein the hindered phenol antioxidant mainly plays an antioxidant role by capturing free radicals and interrupting the chain reaction; the ester antioxidant mainly plays an antioxidant role by decomposing peroxides and preventing them from further inducing free radicals; by compounding the two, the oxidation reaction process can be blocked from different links, thereby synergistically improving the antioxidant performance and stability of the immersion coolant.

[0051] In addition, hindered phenol antioxidants have better antioxidant effects at high temperatures, and ester antioxidants can show better antioxidant effects at medium and low temperatures. After the two are compounded, they can provide effective antioxidant properties in different temperature ranges, which is conducive to making the immersion coolant have a wider operating temperature range.

[0052] In some embodiments, the hindered phenol antioxidant includes one or more of Irganox L107, 2,6-di-tert-butyl-p-cresol (i.e., hindered phenol T 501), Irganox L39, and 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate octadecyl ester. The use of the above-mentioned types of antioxidants as hindered phenol antioxidants can achieve good antioxidant effects. Among them, Irganox L107 is an antioxidant product code-named Irganox L107 produced by BASF, Germany; Irganox L39 is an antioxidant product code-named Irganox L39 produced by BASF, Germany.

[0053] In some embodiments, the ester antioxidant includes one or more of dilauryl thiodipropionate, distearyl thiodipropionate, triphenyl phosphite, tri(nonylphenyl) phosphite and pentaerythritol tetrakis(3-dodecyloxythiopropionate).

[0054] In some embodiments, the weight ratio of the hindered phenolic antioxidant to the ester antioxidant is 3 to 8: 2. In the composite antioxidant, the hindered phenolic antioxidant is used as the main antioxidant, the ester antioxidant is used as the auxiliary antioxidant, and the hindered phenolic antioxidant and the ester antioxidant are compounded according to the above weight ratio, which is more conducive to improving the antioxidant performance and stability of the immersion coolant.

[0055] It is understandable that the weight ratio of hindered phenol antioxidant to ester antioxidant in the composite antioxidant can be 3:2, 3.5:2, 4:2, 4.5:2, 5:2, 5.5:2, 6:2, 6.5:2, 7:2, 7.5:2, 8:2 and any ratio within the range formed by any two of the above ratios.

[0056] In some specific examples, the pour point depressant includes one or more of a polymethacrylate type pour point depressant and a modified polymethacrylate type pour point depressant. The use of the above pour point depressants is beneficial to lowering the pour point of the immersion coolant and improving the low temperature fluidity of the immersion coolant.

[0057] Among them, the modified polymethacrylate type pour point depressant is obtained by adjusting the structure of polymethacrylate or introducing other functional groups to further optimize its pour point depressing performance. Specifically, the introduced modified functional groups include one or more of long-chain alkyl, alcohol with branched structure, hydroxyl, carboxyl, amino and the like.

[0058] In some of the embodiments, the immersion coolant also includes 0.05 to 0.3 parts of defoaming agent by weight. The immersion coolant usually needs to circulate when in use to improve the cooling effect. During the circulation process, the immersion coolant may generate a large number of bubbles, which will form cavitation, causing the battery thermal management device or the surface metal of the battery in contact with the immersion coolant to become embrittled, resulting in metal corrosion. By adding the above-mentioned specific amount of defoaming agent and compounding with other components to the immersion coolant, it is helpful to reduce the amount of bubbles formed by the coolant during use, thereby alleviating the corrosion effect on the surface metal.

[0059] In some of the embodiments, the total weight fractions of the poly-alpha-olefin synthetic base oil PAO 2, the poly-alpha-olefin synthetic base oil PAO 4, the antioxidant, the pour point depressant and the defoaming agent in the immersion coolant is 100 parts.

[0060] In some embodiments, the defoaming agent includes one or more of a nonionic surfactant, an aliphatic defoaming agent, and an aromatic hydrocarbon defoaming agent. By using the above defoaming agent, the amount of bubbles formed in the coolant during use can be effectively reduced, and the corrosion of the surface metal can be alleviated.

[0061] Among them, the nonionic surfactant can be a polyether nonionic surfactant, a fatty acid polyoxyethylene ester nonionic surfactant and an alkyl alcohol amide nonionic surfactant. Aliphatic defoamers are mainly composed of aliphatic compounds, and the carbon chain in their molecular structure is a straight or branched saturated or unsaturated aliphatic hydrocarbon. Specifically, aliphatic defoamers can be stearic acid, lauryl alcohol, etc. Aromatic hydrocarbon defoamers are mainly composed of compounds containing aromatic ring structures, and their molecules usually contain one or more aromatic structures such as benzene rings. Specifically, aromatic hydrocarbon defoamers can be alkylbenzene sulfonates, phenyl silicone oils, etc.

[0062] In one embodiment of the present application, a method for preparing the above-mentioned immersion coolant is provided, and the preparation method comprises the following steps: providing raw materials according to the components of the above-mentioned immersion coolant of the present application; stirring and mixing the raw materials evenly to obtain the immersion coolant.

[0063] In some embodiments, the stirring and mixing temperature is 45°C to 65°C, the stirring and mixing speed is 1000r / min to 2000r / min, and the stirring and mixing time is 2h to 3h. Under the above stirring and mixing temperature, stirring and mixing speed and stirring and mixing time conditions, it is beneficial to fully mix the raw material components of the immersion coolant to form an immersion coolant with uniform composition and stable performance.

[0064] It can be understood that the temperature of the stirring and mixing can be 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C, 65°C and any value within the range formed by any two of the above values; the stirring speed of the stirring and mixing can be 1000r / min, 1100r / min, 1200r / min, 1300r / min, The speeds may be as follows: 1400 r / min, 1500 r / min, 1600 r / min, 1700 r / min, 1800 r / min, 1900 r / min, 2000 r / min and any value within the range formed by any two of the above values; the stirring and mixing time may be 2 h, 2.1 h, 2.2 h, 2.3 h, 2.4 h, 2.5 h, 2.6 h, 2.7 h, 2.8 h, 2.9 h, 3 h and any value within the range formed by any two of the above values.

[0065] In some embodiments, after the raw materials are stirred and mixed evenly, the mixed solution is further allowed to stand for cooling for 2h to 3h and then filtered. By leaving the raw materials after stirring and mixing to stand for cooling for 2h to 3h and then filtering, some solid impurities in the immersion coolant can be removed, further improving the uniformity of the immersion coolant. It is understood that the time for standing and cooling can be 2h, 2.1h, 2.2h, 2.3h, 2.4h, 2.5h, 2.6h, 2.7h, 2.8h, 2.9h, 3h and any value within the range formed by any two of the above values.

[0066] The immersion coolant of the present application can be used as a coolant material in a battery thermal management device. In addition, the immersion coolant can also be used in other fields that require cooling and heat dissipation to extend the life of the equipment. For example, it can be used in the cooling systems of data center servers, high-performance computers, avionics equipment, medical imaging equipment, etc.

[0067] In one embodiment of the present application, a battery device is provided, which includes a box, a battery cell and the immersion coolant mentioned above in the present application. The battery cell and the immersion coolant are accommodated in the box, and the battery cell is at least partially immersed in the immersion coolant.

[0068] The immersion coolant in the battery device is used to immerse the battery cells in cooling, thereby protecting the battery cells and extending the service life of the battery cells. Specifically, the battery cells can be partially or completely immersed in the immersion coolant. The battery device is mainly used to ensure that the battery cells can be kept within the optimal operating temperature range under various working conditions and environmental conditions, thereby improving battery performance, extending service life and ensuring safety.

[0069] Furthermore, the battery device may also include a thermal management fluid circuit, a heating system, a temperature detection and control system, etc. Among them, the thermal management fluid circuit includes a coolant, a pipe and a radiator. The coolant is used to cool down the battery cells. The immersion coolant usually contacts the battery cells directly to dissipate heat; the pipe is responsible for the circulation of the coolant in the battery pack; the radiator is used to dissipate the heat in the coolant to the external environment. The heating system usually includes a heater, which is used to heat the coolant or directly heat the battery pack to increase the battery temperature when the battery temperature is too low. The temperature detection and control system usually includes a temperature sensor and a control unit. The temperature sensor is used to monitor the temperature of the battery in real time and feed back the temperature information to the control unit; the control unit receives the battery temperature signal from the temperature sensor, and regulates the heating system or cooling equipment according to the preset temperature range, thereby managing the battery temperature.

[0070] In one embodiment of the present application, an electric device is provided, including the battery device described above in the present application. As a non-limiting example, the electric device may be a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, etc.

[0071] In order to make the technical problems, technical solutions and beneficial effects solved by the present application clearer, the present application will be further described in detail in conjunction with the embodiments below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its applications. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0072] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0073] Embodiment 1:

[0074] 42g of polyalphaolefin synthetic base oil PAO 2, 57g of polyalphaolefin synthetic base oil PAO 4, 0.5g of 2,6-di-tert-butyl-p-cresol antioxidant (hindered phenol T 501), 0.2g of dilauryl thiodipropionate antioxidant, 0.2g of modified polymethacrylate type pour point depressant (TC-256P) and 0.2g of Synative AC AMH 2 defoamer were prepared respectively. Among them, the kinematic viscosity of PAO 2 at 100°C is 2.3mm 2 / s, viscosity index is 124; the kinematic viscosity of PAO 4 at 100℃ is 3.93mm2 / s, viscosity index is 132.

[0075] The polyalphaolefin synthetic base oil PAO 2 and the polyalphaolefin synthetic base oil PAO 4 are mixed, and the 2,6-di-tert-butyl-p-cresol antioxidant, Irganox L107 antioxidant, TC-256P pour point depressant and Synative AC AMH 2 defoaming agent are added to the mixed base oil under stirring at 45° C. and 1000 r / min, and then stirred for 2 hours, allowed to stand for 2 hours, and then filtered and packaged to obtain an immersion coolant.

[0076] Embodiment 2:

[0077] 45 g of polyalphaolefin synthetic base oil PAO 2, 54 g of polyalphaolefin synthetic base oil PAO 4, 0.5 g of 2,6-di-tert-butyl-p-cresol antioxidant (hindered phenol T 501), 0.2 g of Irganox L107 antioxidant, 0.2 g of modified polymethacrylate type pour point depressant (TC-256P) and 0.2 g of Synative AC AMH 2 defoaming agent were prepared respectively.

[0078] The polyalphaolefin synthetic base oil PAO 2 and the polyalphaolefin synthetic base oil PAO 4 are mixed, and the 2,6-di-tert-butyl-p-cresol antioxidant, Irganox L107 antioxidant, TC-256P pour point depressant and Synative AC AMH 2 defoaming agent are added to the mixed base oil under stirring at 45° C. and 1000 r / min, and then stirred for 2 hours, allowed to stand for 2 hours, and then filtered and packaged to obtain an immersion coolant.

[0079] Embodiment 3:

[0080] 47 g of polyalphaolefin synthetic base oil PAO 2, 52 g of polyalphaolefin synthetic base oil PAO 4, 0.5 g of 2,6-di-tert-butyl-p-cresol antioxidant (hindered phenol T 501), 0.2 g of Irganox L107 antioxidant, 0.2 g of modified polymethacrylate type pour point depressant (TC-256P) and 0.2 g of Synative AC AMH 2 defoaming agent were prepared respectively.

[0081] The polyalphaolefin synthetic base oil PAO 2 and the polyalphaolefin synthetic base oil PAO 4 are mixed, and the 2,6-di-tert-butyl-p-cresol antioxidant, Irganox L107 antioxidant, TC-256P pour point depressant and Synative AC AMH 2 defoaming agent are added to the mixed base oil under stirring at 45° C. and 1000 r / min, and then stirred for 2 hours, allowed to stand for 2 hours, and then filtered and packaged to obtain an immersion coolant.

[0082] Embodiment 4:

[0083] 49 g of polyalphaolefin synthetic base oil PAO 2, 50 g of polyalphaolefin synthetic base oil PAO 4, 0.5 g of 2,6-di-tert-butyl-p-cresol antioxidant (hindered phenol T 501), 0.2 g of Irganox L107 antioxidant, 0.2 g of modified polymethacrylate type pour point depressant (TC-256P) and 0.2 g of Synative AC AMH 2 defoamer were prepared respectively.

[0084] The polyalphaolefin synthetic base oil PAO 2 and the polyalphaolefin synthetic base oil PAO 4 are mixed, and the 2,6-di-tert-butyl-p-cresol antioxidant, Irganox L107 antioxidant, TC-256P pour point depressant and Synative AC AMH 2 defoaming agent are added to the mixed base oil under stirring at 45° C. and 1000 r / min, and then stirred for 2 hours, allowed to stand for 2 hours, and then filtered and packaged to obtain an immersion coolant.

[0085] Embodiment 5:

[0086] 42 g of polyalphaolefin synthetic base oil PAO 2, 57 g of polyalphaolefin synthetic base oil PAO 4, 0.42 g of 2,6-di-tert-butyl-p-cresol antioxidant (hindered phenol T 501), 0.28 g of Irganox L107 antioxidant, 0.2 g of modified polymethacrylate type pour point depressant (TC-256P) and 0.2 g of Synative AC AMH 2 defoaming agent were prepared respectively.

[0087] The polyalphaolefin synthetic base oil PAO 2 and the polyalphaolefin synthetic base oil PAO 4 are mixed, and the 2,6-di-tert-butyl-p-cresol antioxidant, Irganox L107 antioxidant, TC-256P pour point depressant and Synative AC AMH 2 defoaming agent are added to the mixed base oil under stirring at 45° C. and 1000 r / min, and then stirred for 2 hours, allowed to stand for 2 hours, and then filtered and packaged to obtain an immersion coolant.

[0088] Embodiment 6:

[0089] 42 g of polyalphaolefin synthetic base oil PAO 2, 57 g of polyalphaolefin synthetic base oil PAO 4, 0.56 g of 2,6-di-tert-butyl-p-cresol antioxidant (hindered phenol T 501), 0.14 g of Irganox L107 antioxidant, 0.2 g of modified polymethacrylate type pour point depressant (TC-256P) and 0.2 g of Synative AC AMH 2 defoaming agent were prepared respectively.

[0090] The polyalphaolefin synthetic base oil PAO 2 and the polyalphaolefin synthetic base oil PAO 4 are mixed, and the 2,6-di-tert-butyl-p-cresol antioxidant, Irganox L107 antioxidant, TC-256P pour point depressant and Synative AC AMH 2 defoaming agent are added to the mixed base oil under stirring at 45° C. and 1000 r / min, and then stirred for 2 hours, allowed to stand for 2 hours, and then filtered and packaged to obtain an immersion coolant.

[0091] Embodiment 7:

[0092] 42 g of polyalphaolefin synthetic base oil PAO 2, 57 g of polyalphaolefin synthetic base oil PAO 4, 0.06 g of 2,6-di-tert-butyl-p-cresol antioxidant (hindered phenol T 501), 0.04 g of Irganox L107 antioxidant, 0.2 g of modified polymethacrylate type pour point depressant (TC-256P) and 0.2 g of Synative AC AMH 2 defoaming agent were prepared respectively.

[0093] The polyalphaolefin synthetic base oil PAO 2 and the polyalphaolefin synthetic base oil PAO 4 are mixed, and the 2,6-di-tert-butyl-p-cresol antioxidant, Irganox L107 antioxidant, TC-256P pour point depressant and Synative AC AMH 2 defoaming agent are added to the mixed base oil under stirring at 45° C. and 1000 r / min, and then stirred for 2 hours, allowed to stand for 2 hours, and then filtered and packaged to obtain an immersion coolant.

[0094] Embodiment 8:

[0095] 42 g of polyalphaolefin synthetic base oil PAO 2, 57 g of polyalphaolefin synthetic base oil PAO 4, 0.7 g of 2,6-di-tert-butyl-p-cresol antioxidant (hindered phenol T 501), 0.2 g of Irganox L107 antioxidant, 0.2 g of modified polymethacrylate type pour point depressant (TC-256P) and 0.2 g of Synative AC AMH 2 defoaming agent were prepared respectively.

[0096] The polyalphaolefin synthetic base oil PAO 2 and the polyalphaolefin synthetic base oil PAO 4 are mixed, and the 2,6-di-tert-butyl-p-cresol antioxidant, Irganox L107 antioxidant, TC-256P pour point depressant and Synative AC AMH 2 defoaming agent are added to the mixed base oil under stirring at 45° C. and 1000 r / min, and then stirred for 2 hours, allowed to stand for 2 hours, and then filtered and packaged to obtain an immersion coolant.

[0097] Embodiment 9:

[0098] 42 g of polyalphaolefin synthetic base oil PAO 2, 57 g of polyalphaolefin synthetic base oil PAO 4, 0.5 g of 2,6-di-tert-butyl-p-cresol antioxidant (hindered phenol T 501), 0.2 g of Irganox L107 antioxidant, 0.4 g of modified polymethacrylate type pour point depressant (TC-256P) and 0.2 g of Synative AC AMH 2 defoaming agent were prepared respectively.

[0099] The polyalphaolefin synthetic base oil PAO 2 and the polyalphaolefin synthetic base oil PAO 4 are mixed, and the 2,6-di-tert-butyl-p-cresol antioxidant, Irganox L107 antioxidant, TC-256P pour point depressant and Synative AC AMH 2 defoaming agent are added to the mixed base oil under stirring at 45° C. and 1000 r / min, and then stirred for 2 hours, allowed to stand for 2 hours, and then filtered and packaged to obtain an immersion coolant.

[0100] Embodiment 10:

[0101] 42 g of polyalphaolefin synthetic base oil PAO 2, 57 g of polyalphaolefin synthetic base oil PAO 4, 0.5 g of 2,6-di-tert-butyl-p-cresol antioxidant (hindered phenol T 501), 0.2 g of Irganox L107 antioxidant, 0.2 g of modified polymethacrylate type pour point depressant (TC-256P) and 0.05 g of Synative AC AMH 2 defoamer were prepared respectively.

[0102] The polyalphaolefin synthetic base oil PAO 2 and the polyalphaolefin synthetic base oil PAO 4 are mixed, and the 2,6-di-tert-butyl-p-cresol antioxidant, Irganox L107 antioxidant, TC-256P pour point depressant and Synative AC AMH 2 defoaming agent are added to the mixed base oil under stirring at 45° C. and 1000 r / min, and then stirred for 2 hours, allowed to stand for 2 hours, and then filtered and packaged to obtain an immersion coolant.

[0103] Comparative Example 1:

[0104] This comparative example is basically the same as Example 1, except that: the same quality of Esterex A 32 base oil produced by Lubrizol Corporation of the United States is used to replace the poly-alpha-olefin synthetic base oil PAO 2, and the same quality of Esterex A 41 base oil produced by ExxonMobil Corporation is used to replace the poly-alpha-olefin synthetic base oil PAO 4. The kinematic viscosity of Esterex A 32 at 100°C is 6.6 mm 2 / s, viscosity index is 168; Esterex A 41 has a kinematic viscosity of 8.3 mm at 100°C 2 / s, viscosity index is 149.

[0105] Comparative Example 2:

[0106] This comparative example is basically the same as Example 1, except that the same mass of poly-α-olefin synthetic base oil PAO6 is used instead of poly-α-olefin synthetic base oil PAO 2. The kinematic viscosity of PAO 6 at 100°C is 5.76 mm 2 / s, viscosity index is 134.

[0107] Comparative Example 3:

[0108] This comparative example is substantially the same as Example 1, except that the amount of the poly-α-olefin synthetic base oil PAO 2 is reduced to 30 g.

[0109] Comparative Example 4:

[0110] This comparative example is substantially the same as Example 1, except that the amount of the poly-α-olefin synthetic base oil PAO 4 is reduced to 40 g.

[0111] Test method:

[0112] The performance of the immersion coolant and its raw materials in the above embodiments and comparative examples was tested, mainly including tests such as the kinematic viscosity of the base oil at 100°C, the viscosity index of the base oil, the specific heat capacity of the coolant, the antioxidant capacity of the coolant, the breakdown voltage of the coolant, the volume conductivity of the coolant, the viscosity of the coolant at 100°C, and the pour point of the coolant.

[0113] in:

[0114] Base oil 100℃ kinematic viscosity test: Refer to GB / T 265 standard and test the kinematic viscosity of base oil at 100℃.

[0115] Base oil viscosity index test: According to GB / T 265 standard, the kinematic viscosity of the base oil is tested at 40℃ and 100℃ respectively, and the viscosity index of the base oil is calculated according to GB / T 1995.

[0116] Coolant specific heat capacity test: Refer to ASTM D7896-19 test method to test the specific heat capacity of the coolant at 50°C.

[0117] Coolant thermal conductivity test: Refer to ASTM D7896-19 test method to test the thermal conductivity of the coolant at 50°C.

[0118] Coolant antioxidant capacity test: The anti-oxidation capacity of the coolant was tested at 150°C using the rotating oxygen bomb method.

[0119] Coolant breakdown voltage test: Refer to GB / T 507-2002 test method to test the coolant breakdown voltage.

[0120] Coolant volume conductivity test: Refer to the "YDT_3982-2021 Technical Requirements and Test Methods for Cooling Liquids in Data Center Liquid Cooling Systems" standard, and use the GB / T 5654-2007 method to test the volume conductivity of the coolant at 20°C.

[0121] Coolant viscosity test at 100℃: Same as the test method for base oil kinematic viscosity at 100℃.

[0122] Coolant pour point test: Refer to GB / T 3535-2006 standard and use a pour point tester to test the pour point of the coolant under low temperature conditions.

[0123] The parameters of the immersion cooling liquid of each embodiment and comparative example are shown in Table 1:

[0124] Table 1

[0125]

[0126] The performance data of the immersion coolant of each embodiment and comparative example are shown in Table 2:

[0127] Table 2

[0128]

[0129] As can be seen from Table 1 and Table 2, the immersion coolant of each embodiment of the present application has a low pour point, a low viscosity and a suitable viscosity index at 100°C, and has good fluidity; has a suitable volume conductivity and a high breakdown voltage, has good thermal stability and electrochemical stability, and has good antioxidant properties; at the same time, has a high specific heat capacity and thermal conductivity, and has good heat transfer performance. The immersion coolant of the present application has good fluidity, stability and heat transfer performance at the same time, and can better meet the performance requirements of the battery thermal management device for the coolant.

[0130] Compared with Example 1, Esterex A 32 base oil and Esterex A 41 base oil are used to replace the poly-alpha-olefin synthetic base oil PAO 2 and the poly-alpha-olefin synthetic base oil PAO 4, respectively. The pour point of the coolant in Comparative Example 1 is increased, the viscosity at 100°C and the viscosity index are high, and its flow performance and low-temperature performance are poor; the specific heat capacity of the coolant in Comparative Example 1 is significantly decreased, the thermal conductivity is reduced, and its heat transfer performance is poor; the breakdown voltage of the coolant in Comparative Example 1 is small, and the electrochemical stability is poor.

[0131] Compared with Example 1, Comparative Example 2 uses poly-alpha-olefin synthetic base oil PAO 6 instead of poly-alpha-olefin synthetic base oil PAO 2. The 100° C. viscosity and viscosity index of the coolant in Comparative Example 2 are higher, and its flow performance is poor; and the specific heat capacity and thermal conductivity of the coolant in Comparative Example 2 are lower, and its heat transfer performance is poor.

[0132] Comparative Example 3 Compared with Example 1, the amount of polyalphaolefin synthetic base oil PAO 2 is too small, the breakdown voltage of the coolant is low, the electrochemical stability is poor, and the anti-oxidation performance is reduced. Comparative Example 4 Compared with Example 1, the amount of polyalphaolefin synthetic base oil PAO 4 is too small, the specific heat capacity and thermal conductivity of the coolant are low, and the heat transfer performance is reduced; the viscosity index of the coolant is low, the amplitude of the change of the coolant viscosity with temperature increases, the low-temperature fluidity decreases, and the heat dissipation efficiency of the coolant at high temperature decreases; in addition, the anti-oxidation performance of the coolant decreases.

[0133] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0134] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. An immersion coolant, characterized in that: The components are as follows by weight: 40 to 50 parts of polyalphaolefin synthetic base oil PAO 2, 50 to 60 parts of polyalphaolefin synthetic base oil PAO 4, 0.1 to 0.4 parts of pour point depressant and 0.1 to 0.9 parts of antioxidant.

2. The immersion cooling liquid according to claim 1, characterized in that: The components are as follows by weight: 45 to 49 parts of polyalphaolefin synthetic base oil PAO 2, 50 to 54 parts of polyalphaolefin synthetic base oil PAO 4, 0.1 to 0.4 parts of pour point depressant and 0.1 to 0.9 parts of antioxidant.

3. The immersion cooling liquid according to claim 1 or 2, characterized in that: The kinematic viscosity of the poly-alpha-olefin synthetic base oil PAO2 at 100°C is 1 mm 2 / s~3mm 2 / s, and the viscosity index of the poly-alpha-olefin synthetic base oil PAO 2 is greater than or equal to 90.

4. The immersion cooling liquid according to claim 1 or 2, characterized in that: The kinematic viscosity of the poly-alpha-olefin synthetic base oil PAO4 at 100°C is 3.6 mm 2 / s~4.9mm 2 / s, and the viscosity index of the poly-alpha-olefin synthetic base oil PAO 4 is greater than or equal to 120.

5. The immersion cooling liquid according to claim 1 or 2, characterized in that: The antioxidant includes one or more of a hindered phenol antioxidant and an ester antioxidant.

6. The immersion cooling liquid according to claim 5, characterized in that: Meet one or more of the following: (1) The hindered phenol antioxidant includes one or more of Irganox L107, 2,6-di-tert-butyl-p-cresol, Irganox L39 and octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate; (2) The ester antioxidant includes one or more of dilauryl thiodipropionate, distearyl thiodipropionate, triphenyl phosphite, tri(nonylphenyl) phosphite and pentaerythritol tetrakis(3-dodecyloxythiopropionate).

7. The immersion cooling liquid according to claim 5, characterized in that The antioxidant comprises a hindered phenol antioxidant and an ester antioxidant, and the weight ratio of the hindered phenol antioxidant to the ester antioxidant is 3-8:

2.

8. The immersion cooling liquid according to any one of claims 1 to 2, 6 to 7, characterized in that: The pour point depressant includes one or more of polymethacrylate pour point depressants and modified products thereof.

9. The immersion cooling liquid according to any one of claims 1 to 2, 6 to 7, characterized in that: The composition also includes 0.05 to 0.3 parts of defoaming agent by weight.

10. The immersion cooling liquid according to claim 9, characterized in that The defoaming agent includes one or more of a nonionic surfactant, an aliphatic defoaming agent and an aromatic hydrocarbon defoaming agent.

11. A method for preparing an immersion cooling liquid, characterized in that: The steps include: Providing raw materials according to the components of the immersion cooling liquid according to any one of claims 1 to 10; The raw materials are stirred and mixed uniformly to obtain the immersion cooling liquid.

12. The method for preparing the immersion cooling liquid according to claim 11, characterized in that: The stirring and mixing temperature is 45° C. to 65° C., the stirring and mixing speed is 1000 r / min to 2000 r / min, and the stirring and mixing time is 2 h to 3 h.

13. The method for preparing an immersion cooling liquid according to claim 11 or 12, characterized in that: After the raw materials are stirred and mixed evenly, the method further includes the steps of allowing the mixed solution to stand and cool for 2 hours to 3 hours and then filtering to obtain the filtrate.

14. A battery device, characterized in that: The invention comprises a box, a battery cell and the immersion cooling liquid according to any one of claims 1 to 10, wherein the battery cell and the immersion cooling liquid are accommodated in the box, and the battery cell is at least partially immersed in the immersion cooling liquid.

15. An electrical device, characterized in that: A battery device comprising the battery device of claim 14.

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