DIELECTRIC THERMAL MANAGEMENT FLUIDS AND METHODS FOR USING THEREOF - Patent application

Abstract

More specifically, the present disclosure provides dielectric thermal management fluids suitable for use in managing heat in battery systems via direct cooling, such as lithium-ion batteries used in electric vehicles, electric motors, and power electronics, methods of using such thermal management fluids, and systems including such thermal management systems. The present disclosure relates generally to administration fluids for thermal management of medical devices. More specifically, the present disclosure relates to medical devices. Electrical thermal management fluids suitable for use in managing heat in battery systems through direct cooling. Applications include devices used in lithium ion battery electric vehicles, electric motors, electronics and methods of using such thermal management fluids, and systems including such thermal management systems.

Description

[Technical field]

[0001] This invention relates generally to thermal management fluids. More specifically, the present disclosure relates to dielectric thermal management fluids suitable for use in managing heat in battery systems via direct cooling, such as lithium ion batteries used in electric vehicles, electric motors, and power electronics, methods of using such thermal management fluids, and systems including such thermal management systems. [Background technology]

[0002] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 153,148, filed February 24, 2021, which is incorporated by reference in its entirety herein.

[0003] The number of global sales of electric vehicles (i.e., vehicles that use electric power for all or part of their motive power, such as battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), etc.) has increased over the past few years and is expected to continue to increase. Eventually, the majority of vehicles will likely be electric. As electric vehicle technology continues to develop, there is a need to provide improved power sources (e.g., battery systems or modules). For example, it is desirable to increase the distance such vehicles can travel without the need to recharge the batteries, improve the performance of such batteries, and reduce the costs and time associated with battery charging.

[0004] Most batteries generate heat when current is supplied to or drawn from the battery. Generally, as the amount of current flowing into or out of the battery increases, so does the amount of heat generated. If the generated heat is not dissipated, the temperature of the battery will increase. Most batteries have an effective operating temperature range, and if the battery exceeds the maximum operating temperature, the battery may become ineffective or even undergo thermal runaway and failure. In some cases, after a slight increase in temperature, the battery may be able to dissipate the heat to its surroundings through a simple heat sink or without any thermal management. In other cases, a more specific thermal management system is required to dissipate the heat generated by the battery.

[0005] Currently, battery-powered electric vehicles use lithium-ion battery technology almost exclusively. Lithium-ion batteries offer many advantages over comparable nickel-metal hydride batteries, but compared to nickel-metal hydride batteries, lithium-ion batteries are more susceptible to fluctuations in battery temperature and therefore have more stringent thermal management requirements. For example, the optimal lithium-ion battery operating temperature ranges from 10 to 35 °C. As temperatures increase from 35 °C to 70 °C, operation becomes increasingly inefficient and, more critically, operation at these temperatures can damage the battery over time. Temperatures above 70 °C present an increased risk of thermal runaway. As a result, lithium-ion batteries require specific thermal management systems to regulate their temperature during vehicle operation. Also, when charging, up to 10% of the input power ends up as heat. As fast charging of lithium-ion batteries becomes more commonplace, there is still a need for efficient systems for thermal management of the batteries.

[0006] Lithium-ion batteries can be cooled directly or indirectly using a thermal management fluid (i.e., as a cooling fluid or coolant) to carry heat away from the battery components. Direct cooling advantageously allows the thermal management fluid to be in direct contact with the hot components to carry heat away from them. In indirect cooling, the hot components are electrically shielded by an electrically insulating barrier, and the thermal management fluid carries heat away passing through the barrier. The most common thermal management fluids are based on mixtures of water and glycol. However, water, although these fluids typically conduct electricity, cannot be used for direct cooling of the electrical components of lithium-ion batteries. Indirect cooling allows the use of water-based coolants, but the requirement of electrical shielding can create a bottleneck of heat flow in the cooling process. There are dielectric thermal management fluids that can be used for direct cooling of electrical components due to their non-conductive nature, examples include those traditionally used for transformer cooling. However, the thermal properties of such dielectric thermal management fluids are typically poor compared to water-glycol. Summary of the Invention [Problem to be solved by the invention]

[0007] Thus, there remains a need for improved dielectric thermal management systems, particularly those suitable for use in cooling lithium-ion batteries. [Means for solving the problem]

[0008] One aspect of the present disclosure provides a thermal management fluid having a flash point, as measured according to ASTM D93, of at least 100° C. and a dielectric constant of at least 1.5 at 25° C. Such dielectric thermal management fluids include: One or more dielectric compounds of formula (1)

[0009] [ka] m is an integer 1, 2, or 3; n is an integer 1, 2, 3, 4, 5, 6, 7, or 8; R1 is C6-C12 alkyl; R2 is a C6-C12 alkyl; Each Rs and Ra is independently selected from H and C1-C6 alkyl; each Rs and Re is independently selected from H and C1-C6 alkyl; The one or more dielectric compounds are present in the thermal management fluid in a total amount ranging from 1% to 100% by weight, based on the total weight of the thermal management fluid.

[0010] Another aspect of the present disclosure provides a battery system including a housing, one or more electrochemical cells disposed within the housing, a fluid pathway extending within the housing and in substantial thermal communication with the one or more electrochemical cells, and a thermal management fluid of the present disclosure described herein disposed within the fluid pathway.

[0011] In another aspect, the present disclosure provides an electric vehicle comprising the battery system of the present disclosure described herein.

[0012] In another aspect, the present disclosure provides a thermal management circuit including a fluid pathway extending around and / or through a heat source, and a thermal management fluid of the present disclosure disposed within the fluid pathway and configured to circulate within the fluid pathway and absorb thermal energy generated by the heat source, the fluid being disposed within the fluid pathway, the heat exchanger, the pump, and the connecting ducts.

[0013] Another aspect of the present disclosure provides a method including contacting a thermal management fluid of the present disclosure with a surface having a temperature of at least 25° C. (e.g., at least 30° C.), where the surface is in substantial thermal communication with a heat source, and absorbing thermal energy from the heat source through the surface into the thermal management fluid.

[0014] Another aspect of the present disclosure provides a method for preparing the thermal management fluids of the present disclosure, comprising the steps of:

[0015] [ka] m is an integer 1, 2, or 3; n is an integer 1, 2, 3, 4, 5, 6, 7, or 8; each Ra, R4, Rs and Re is independently selected from H and C1-C6 alkyl, reacting with (C6-C12 alkyl)-L, where L is a leaving group, to obtain a dielectric compound of formula (I).

[0016] The accompanying drawings are included to provide a further understanding of the compositions and methods of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings are not necessarily to scale, and sizes of various elements may be distorted for clarity. The drawings illustrate one or more embodiments of the present disclosure and, together with the description, serve to explain the principles and operation of the present disclosure. [Brief description of the drawings]

[0017] [Figure 1] 1 is a schematic cross-sectional view of a thermal management circuit according to one embodiment of the present disclosure. [Diagram 2] 2 is a schematic cross-sectional view of a thermal management circuit according to another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The inventors have noted that desirable thermal management fluids often have a high ability to carry away heat in the temperature range associated with the operation of a particular electrical device or system (e.g., lithium ion batteries), and further have a sufficiently high dielectric constant to make them suitable for use in direct cooling of the device or system. Importantly, desirable thermal management fluids advantageously have a high flash point to reduce the risk of ignition, since there is always a risk of oxygen getting throughout the system. Also, to provide more efficient heat transfer during operation, desirable thermal management fluids advantageously have a low viscosity to allow for better flow in the particular electrical device or system.

[0019] The inventors have identified thermal management fluid compositions that not only provide a desirable low viscosity, but also have a high flash point, so that they can be easily pumped through systems with low or no risk of ignition. Specifically, the inventors have recognized that conventional dielectric fluids (e.g., organic or silicone) typically have good thermal conductivity and specific heat capacity, but undesirably high viscosity. However, typical low viscosity dielectric fluids generally have unacceptably low flash points (and other ignition properties), making them unsuitable for use as coolants in systems where elevated temperatures are possible where ignition is a danger. The inventors have found that the dielectric compounds of the present disclosure can provide thermal management fluids that do not have low flash points and advantageously have low viscosity. These properties of the thermal management fluids make them particularly suitable for direct cooling of, for example, electrical devices and systems.

[0020] The thermal management fluids and methods of the present disclosure may have several additional advantages over conventional fluids. In particular, the thermal management fluids of the present disclosure may also provide one or more of a desirably high thermal conductivity, a low ignition risk, a high dielectric constant, and a fast temperature response, in various embodiments. The thermal management fluids of the present disclosure may also have a lower surface tension than conventional low viscosity dielectric fluids, in various embodiments.

[0021] Accordingly, one aspect of the present disclosure provides a thermal management fluid comprising one or more dielectric compounds of formula (I), the one or more dielectric compounds being present in a total amount ranging from 1% to 100% by weight. Such thermal management fluids may have a flash point of at least 100° C., as measured according to ASTM D93 (“Standard Test Methods for Flash Point by Pensky-Martens Closed Cup Tester”), and a dielectric constant of at least 1.5 at 25° C.

[0022] Since there is always some risk that oxygen may enter the system, the thermal management fluids of the present disclosure advantageously have a high flash point to prevent ignition. As mentioned above, the thermal management fluids of the present disclosure can have a flash point of at least 100° C., as measured according to ASTM D93. For example, in various embodiments, the thermal management fluids described elsewhere herein have a flash point of at least 110° C., e.g., at least 120° C., at least 125° C., at least 130° C., or at least 135° C., as measured according to ASTM D93. In various embodiments, the thermal management fluids described elsewhere herein have a flash point of at least 140° C., e.g., at least 145° C., at least 150° C., at least 155° C., at least 160° C., or at least 165° C., as measured according to ASTM D93. Materials that do not have a flash point below 100° C. are considered to have a flash point above 100° C. for purposes of the present disclosure, even if the flash point cannot be measured for the material (i.e., due to decomposition).

[0023] A low viscosity is often desirable for the thermal management fluid to facilitate pumping of the thermal management fluid through the system, especially when relatively narrow passages are used. One skilled in the art will select ingredients based on the present disclosure to provide a thermal management fluid with a desired viscosity, for example, for convenient transport through the system. Thus, in various embodiments, the thermal management fluids described elsewhere herein have a kinematic viscosity at 40° C. measured according to ASTM D455 in the range of 1.5 to 10 cSt, e.g., 1.5 to 8 cSt, or 2 to 6 cSt, or 2 to 10 cSt, or 2 to 15 cSt, or 3 to 10 cSt, or 3 to 15 cSt, or 5 to 20 cSt, or 5 to 10 cSt, or 8 to 10 cSt. Thus, in various embodiments, the thermal management fluids described elsewhere herein have a kinematic viscosity at 40° C., measured according to ASTM D, in the range of 1.5 to 10 cSt, e.g., 1.5 to 8 cSt, or 1.5 to 6 cSt, or 2 to 10 cSt, or 2 to 10 cSt, or 2 to 6 cSt, or 3 to 10 cSt, or 3 to 8 cSt, or 3 to 6 cSt, or 5 to 10 cSt, or 5 to 8 cSt, or 5 to 6 cSt, or 6 to 10 cSt, or 8 to 10 cSt. Also, in various embodiments, the thermal management fluids described elsewhere herein have a kinematic viscosity at 40° C. in the range of 1.5 to 5 cSt, e.g., 1.5 to 4 cSt, or 1.5 to 3 cSt, or 2 to 5 cSt, or 2 to 4 cSt, or 2 to 3 cSt, or 3 to 5 cSt, or 3 to 4 cSt, or 4 to 5 cSt, as measured according to ASTM D455.

[0024] Thermal management fluids of the present disclosure are desirably dielectric so that they can be used in direct cooling applications. Thus, they have a dielectric constant of at least 1.5 measured at 25° C. The dielectric constant is measured using a coaxial probe method using ASTM D924. In various embodiments, thermal management fluids of the present disclosure have a dielectric constant of at least 1.75, e.g., at least 2.0, or at least 2.25, measured at 25° C. In various embodiments, thermal management fluids of the present disclosure have a dielectric constant in the range of 1.5 to 10, e.g., 1.8 to 10, or 1.5 to 2.8, or 1.8 to 2.8.

[0025] In various embodiments of the present disclosure, the thermal management fluids of the present disclosure may have a density of 1.1 g / cm or less at 25° C. For example, in various embodiments of the present disclosure, the thermal management fluids of the present disclosure may have a density of 1 g / cm or less at 25° C.

[0026] In various embodiments of the present disclosure, the thermal management fluids of the present disclosure may have a heat capacity of at least 1 J / gK, or at least 1.2 J / gK, or even at least 1.5 J / gK at 25° C. In various embodiments of the present disclosure, the thermal management fluids of the present disclosure may have a thermal conductivity in the range of 0.05 W / m·K to 1 W / m·K at 25° C. In various embodiments of the present disclosure, the thermal management fluids of the present disclosure may have a coefficient of thermal expansion of 1100×10-6 / K or less (e.g., 1050×10-6 / K or less, or 1000×10-6 / K or less).

[0027] As discussed above, the thermal management fluids of the present disclosure include one or more dielectric compounds of formula (I).

[0028] In various embodiments, in one or more of the dielectric compounds of formula (I) described elsewhere herein, R 1 is a C6-C10 alkyl, such as a C6-C8 alkyl. In various embodiments of the dielectric compounds of formula (1) of the present disclosure, R 1 is a C8-C12 alkyl, such as a C8-C10 alkyl or a C10-C12 alkyl. In various embodiments of the dielectric compounds of formula (I) of the present disclosure, R is a branched C6-C12 alkyl, such as a branched C6-C10 alkyl, a branched C6-C8 alkyl, a branched C8-C12 alkyl, a branched C8-C10 alkyl, or a branched C10-C12 alkyl. The branching can be, for example, in the alpha or beta position relative to the oxygen atom to which R 1 is bonded. In various embodiments, the branching is in the p-position relative to the oxygen atom. For example, in certain compounds of formula (I), R1 is a p-branched C6-C12 alkyl, such as a p-branched C6-C10 alkyl, a p-branched C6-C8 alkyl, a p-branched C8-C12 alkyl, a p-branched C8-C10 alkyl, or a p-branched C10-C12 alkyl.

[0029] In one or more dielectric compounds of formula (I) described elsewhere herein, R2 is a C6-C10 alkyl, e.g., a C6-C8 alkyl. In various embodiments of the dielectric compounds of formula (I) of the present disclosure, R2 is a C8-C12 alkyl, such as a C8-C10 alkyl or a C10-C12 alkyl. In various embodiments of the dielectric compounds of formula (I) of the present disclosure, R2 is a branched C6-C12 alkyl, such as a branched C6-C10 alkyl, a branched C6-C8 alkyl, a branched C8-C12 alkyl, a branched C8-C10 alkyl, or a branched C10-C12 alkyl. The branching can be, for example, in the alpha or beta position relative to the oxygen atom to which R2 is bonded. In various embodiments, the branching is in the P position relative to the oxygen atom. For example, in certain compounds of formula (I), R2 is a p-branched C6-C12 alkyl, such as a p-branched C6-C10 alkyl, a p-branched C6-C8 alkyl, a p-branched C8-C12 alkyl, a p-branched C8-C10 alkyl, or a p-branched C10-C12 alkyl.

[0030] In various embodiments, in one or more dielectric compounds of formula (I) described herein, each of Ra, Ra', Rs, and Re is independently selected from H and C1-C4 alkyl (e.g., C1-C3 alkyl or C1-C2 alkyl). In certain other embodiments, each of R3, R4, R5, and R6 is independently selected from H and C1 alkyl (i.e., methyl).

[0031] In various embodiments described elsewhere herein, in one or more dielectric compounds of formula (I), each of R3, R4, Rs, and Re is H, i.e., the compound has the formula:

[0032] [ka]

[0033] In various embodiments, in one or more of the dielectric compounds of formula (I) described elsewhere herein, each of R4, R5, and R6 is H, and R3 is H or C1-C6 alkyl. For example, in some embodiments, each of R4, R5, and R6 is H and R3 is C1-C6 alkyl (e.g., C1-C4 alkyl, C1-C3 alkyl, ethyl, or methyl), i.e., the compound has the formula:

[0034] [ka] In various embodiments, R4, R5, and R6 are each independently H, and R3 is C1-C6 alkyl (eg, C1-C4 alkyl, C1-C3 alkyl, ethyl, or methyl).

[0035] In various embodiments, in one or more of the dielectric compounds of formula (I) described elsewhere herein, n is the integer 1 or 2. In various embodiments, n is the integer 2 or 3. In various embodiments, n is the integer 1, i.e., the compound has the formula:

[0036] [ka] In various embodiments, the one or more dielectric compounds have the formula:

[0037] [ka] In various embodiments, the one or more dielectric compounds have the formula:

[0038] [ka] In various embodiments, n is the integer 2, i.e., the compound has the formula:

[0039] [ka] has.

[0040] In various embodiments described elsewhere herein, in one or more of the dielectric compounds of formula (I), m is 1. However, in other embodiments, m is 2, or m is 3.

[0041] In various embodiments described elsewhere herein, in one or more of the dielectric compounds of formula (I), m is an integer 1 or 2 and n is 1.

[0042] In various embodiments described elsewhere herein, in one or more dielectric compounds of formula (1), m is an integer 1, 2, or 3; n is 1; R1 is C6-C12 alkyl; R2 is a C6-C12 alkyl; Rs is H or C1-C3 alkyl; R4, R5 and R6 are independently H.

[0043] In various embodiments described elsewhere herein, in one or more dielectric compounds of formula (I): m is an integer 1, 2, or 3; n is 1; R 1 is C6-C10 alkyl; R2 is a C6-C10 alkyl; R3 is H and C1-C3 alkyl; R4, R5 and R6 are independently H.

[0044] In various embodiments described elsewhere herein, one or more dielectric compounds of formula (I) contain a total number of carbon atoms between 14 and 50 (e.g., between 14 and 40, between 14 and 30, between 14 and 20, between 16 and 50, between 16 and 40, between 16 and 30, between 16 and 20, between 18 and 50, between 18 and 40, between 18 and 30, between 18 and 20, between 20 and 50, between 20 and 40, or between 20 and 30). For example, in various embodiments, one or more dielectric compounds of formula (I) contain a total number of carbon atoms between 18 and 22. In various embodiments, one or more dielectric compounds of formula (I) contain a total number of carbon atoms between 16 and 22. In various embodiments, one or more dielectric compounds of formula (I) contain a total number of carbon atoms between 14 and 20.

[0045] In various embodiments described elsewhere herein, one or more compounds of formula (I) have the structure:

[0046] [ka] wherein Ra and Ro are each independently methyl or ethyl, and Rc and Rd are each independently C3-C7 alkyl, e.g., C4-C6 alkyl. In certain such embodiments, m is 1. In other such embodiments, m is 2.

[0047] In various embodiments described elsewhere herein, one or more compounds of formula (I) have the structure:

[0048] [ka] wherein Ra and Rb are each independently methyl or ethyl, and Rc and Rd are each independently C3-C8 alkyl, e.g., C3-C7 alkyl, C3-C6 alkyl, or C4-C6 alkyl. In certain such embodiments, m is 1. In other such embodiments, m is 2.

[0049] In various embodiments described elsewhere herein, one or more compounds of formula (I) have the structure:

[0050] [ka] wherein each of Ra and Rb is independently methyl or ethyl, and each of Rc and Rd is independently C3-C8 alkyl, e.g., C3-C7 alkyl, C4-C6 alkyl, or C1-C6 alkyl. In certain such embodiments, m is 1. In other such embodiments, m is 2.

[0051] In various embodiments described elsewhere herein, one or more compounds of formula (I) have the structure:

[0052] [ka] wherein each of Ra and Rb is independently methyl or ethyl, and each of Rc and Ra is independently C3-C8 alkyl, e.g., C3-C7 alkyl, C3-C6 alkyl, or C4-C6 alkyl. In certain such embodiments, m is 1. In other such embodiments, m is 2.

[0053] In various embodiments described elsewhere herein, one or more compounds of formula (I) have the structure:

[0054] [ka] wherein each of Ra and Rb is independently methyl or ethyl, and each of Rc and Rd is independently C3-C8 alkyl, e.g., C3-C7 alkyl, C3-C6 alkyl, or C4-C6 alkyl. In certain such embodiments, m is 1. In other such embodiments, m is 2.

[0055] Examples of compounds of formula (1) of the present disclosure include, but are not limited to, the following:

[0056] [ka]

[0057] In various embodiments, one or more of the dielectric compounds of formula (1) is 1,2-bis((2-ethylhexyl)oxy)ethane of the formula:

[0058] [ka]

[0059] In various embodiments described elsewhere herein, one or more dielectric compounds of the thermal management fluid have a flash point of at least 140° C., measured according to ASTM D93. The inventors have advantageously determined that the use of dielectric compounds of the present disclosure having high flash points can provide an overall thermal management fluid with a high flash point, thereby reducing the risk of ignition. In various embodiments of the thermal management fluid described elsewhere herein, one or more dielectric compounds have a flash point of at least 145° C. (e.g., at least 150° C., at least 155° C., at least 150° C., or at least 165° C.), measured according to ASTM D93.

[0060] The inventors have advantageously determined that one or more of the dielectric compounds described herein have a relatively low viscosity, but with a reduced risk of ignition. Thus, in various embodiments of the thermal management fluids described elsewhere herein, the one or more dielectric compounds have a kinematic viscosity at 40° C., measured according to ASTM D455, in the range of 2-10 cSt, e.g., 2-8 cSt, or 2-6 cSt, or 3-10 cSt, or 3-8 cSt, or 3-6 cSt, or 5-10 cSt, or 5-8 cSt, or 5-6 cSt, or 6-10 cSt, or 8-10 cSt. Thus, in various embodiments of the thermal management fluids described elsewhere herein, the one or more dielectric compounds have a kinematic viscosity at 40° C. in the range of 2-10 cSt, e.g., 2-8 cSt, or 2-6 cSt, or 3-10 cSt, or 3-8 cSt, or 3-6 cSt, or 5-10 cSt, or 5-8 cSt, or 5-6 cSt, or 6-10 cSt, or 8-10 cSt, as measured according to ASTM D. Also, in various embodiments of the thermal management fluids described elsewhere herein, the one or more dielectric compounds have a kinematic viscosity at 40° C. in the range of 2-5 cSt, or 2-4 cSt, or 2-3 cSt, or 3-5 cSt, or 3-4 cSt, or 4-5 cSt, as measured according to ASTM D455.

[0061] Those skilled in the art will understand that various combinations of the dielectric compounds of the present disclosure may be used in the thermal management fluids of the present disclosure. Thus, the above-mentioned dielectric compound embodiments may be combined in any number and any combination in the thermal management fluids of the present disclosure. When two or more dielectric compounds are used in the thermal management fluids, the relative amounts of the two may be varied based on the disclosure herein depending on the desired effect. In various embodiments, the mass ratio of the first dielectric compound to the second dielectric compound ranges from 1:9 to 9:1 (e.g., 1:5 to 5:1, or 1:5 to 1:1, or 1:1 to 5:1).

[0062] The one or more dielectric compounds can be present in the thermal management fluids described herein in various amounts. In various embodiments described elsewhere herein, the one or more dielectric compounds are present in a total amount ranging from 1 wt. % to 100 wt. % (e.g., 5 wt. % to 100 wt. %, or 10 wt. % to 100 wt. %, or 20 wt. % to 100 wt. %) based on the total weight of the thermal management fluid. For example, in various embodiments of thermal management fluids as described elsewhere herein, the one or more dielectric compounds are present in a total amount ranging from 1 wt.% to 99.9 wt.% (e.g., 5 wt.% to 99.9 wt.%, or 10 wt.% to 99.9 wt.%, or 20 wt.% to 99.9 wt.%), or 50 wt.% to 99.9 wt.%, such as 75 wt.% to 99.9 wt.%, or 85 wt.% to 99.9 wt.%, or 90 wt.% to 99.9 wt.%, or 95 wt.% to 99.9 wt.%, or 98 wt.% to 99.9 wt.%, based on the total weight of the thermal management fluid. In various embodiments of the thermal management fluid described elsewhere herein, the one or more dielectric compounds are present in a total amount ranging from 1 wt % to 99 wt % (e.g., 5 wt % to 99 wt %, or 10 wt % to 99 wt %, or 20 wt % to 99 wt %), or 50 wt % to 99 wt %, such as 75 wt % to 99 wt %, or 85 wt % to 99 wt %, or 90 wt % to 99 wt %, or 95 wt % to 99 wt %, based on the total weight of the thermal management fluid. In various embodiments of the thermal management fluid described elsewhere herein, the one or more dielectric compounds are present in a total amount ranging from 1 wt % to 95 wt % (e.g., 5 wt % to 95 wt %, or 10 wt % to 95 wt %, or 20 wt % to 95 wt %), or 50 wt % to 95 wt %, such as 75 wt % to 95 wt %, or 85 wt % to 95 wt %, based on the total weight of the thermal management fluid.In various embodiments of the thermal management fluids described elsewhere herein, the one or more dielectric compounds are present in a total amount ranging from 1 wt. % to 85 wt. % (e.g., 5 wt. % to 85 wt. %, or 10 wt. % to 85 wt. %, or 20 wt. % to 85 wt. %, or 50 wt. % to 85 wt. %, e.g., 65 wt. % to 85 wt. %, or 75 wt. % to 85 wt. %, based on the total weight of the thermal management fluid. One of ordinary skill in the art, based on the disclosure herein, will provide the dielectric compounds in an amount that provides the thermal management fluid with a desired high flash point, in addition to any other desired properties (e.g., viscosity).

[0063] As one skilled in the art would understand, the thermal management fluids of the present disclosure can also include various other components, such as those conventional in compositions for thermal management applications. For example, the thermal management fluids may further include an oil, such as a mineral oil, a synthetic oil, or a silicone oil. For example, in various embodiments, the oil is a low viscosity Group II, III, IV, or V base oil as defined by the American Petroleum Institute (API Publication 1509). These are shown in Table 1. Table 1 - Base Oil Stocks API Guidelines

[0064] [Table 1]

[0065] Group II and Group III base oils (e.g., hydrocracked and hydrotreated base oils, as well as synthetic oils such as hydrocarbon oils, polyalphaolefins, alkylaromatics, and synthetic esters), and Group IV base oils (e.g., polyalphaolefins (PAOs)) are well-known base oils. Oils suitable for use as transformer oils may, in many embodiments, be suitable for use in the compositions, systems, and methods of the present disclosure. For example, esters also form useful base stocks, including synthetic esters, as well as GTL (gas-to-liquid) materials, particularly those derived from hydrocarbon sources. For example, esters of dibasic acids with monoalcohols, or polyol esters of monocarboxylic acids may be useful as base stocks of the present disclosure.

[0066] In various embodiments, the thermal management fluids of the present disclosure further comprise a Group II, Group III, Group IV, or Group V base oil. For example, in various embodiments, the thermal management fluids of the present disclosure further comprise a Group II or Group III base oil. In certain other embodiments, the thermal management fluids of the present disclosure further comprise a Group IV base oil, such as a polyalphaolefin (PAO). In certain other embodiments, the thermal management fluids of the present disclosure further comprise an ester base oil stock.

[0067] In various embodiments, the thermal management fluids of the present disclosure further comprise one or more of corrosion inhibitors, antioxidants (such as phenolic and amine-based antioxidants), pour point depressants, antifoam agents, defoamers, viscosity index modifiers, preservatives, biocides, surfactants, seal swell additives, and combinations thereof. In various embodiments, corrosion inhibitors, antioxidants (such as phenolic and amine-based antioxidants) may be used. For example, antioxidants (e.g., oxidizers), pour point depressants, antifoam agents, defoamers, viscosity index modifiers, preservatives, biocides, surfactants, seal swell additives, and combinations thereof may be present in an amount of up to 5.0 wt. %, based on the total weight of the thermal management fluid. In certain such embodiments, one or more of the corrosion inhibitors, antioxidants (such as phenolic and aminic antioxidants), pour point depressants, antifoam agents, defoamers, viscosity index modifiers, preservatives, biocides, surfactants, seal swell additives, and combinations thereof are present in an amount ranging from 0.2% to 5.0% by weight, e.g., 1.0% to 2.0% by weight, or 0.2% to 1.0% by weight, or 0.2% to 0.5% by weight, or 0.05% to 0.2% by weight, based on the total weight of the thermal management fluid. In various embodiments, the thermal management fluids of the present disclosure further comprise one or more flame retardants, e.g., in an amount up to 20% by weight, up to 10% by weight, or up to 5% by weight, based on the total weight of the thermal management fluid. However, in other embodiments, no flame retardant performance is present.

[0068] Another aspect of the present disclosure provides a method comprising contacting a thermal management fluid as described herein with a surface having a temperature of at least 25° C., where the surface is in substantial thermal communication with a heat source, and absorbing thermal energy in the thermal management fluid from the heat source through the surface.

[0069] Contact between the thermal management fluid and the surface can be dynamic or static (i.e., conductive). For example, in various embodiments, contact between the thermal management fluid and the surface can be performed by circulating, e.g., pumping or otherwise flowing, the fluid over the surface. In various embodiments, contact can also be performed without circulation, e.g., by contacting the surface with the thermal management fluid that is a stationary body of fluid.

[0070] The temperature of the surface may vary; the thermal management fluid may be adapted for use at a variety of temperatures. In various embodiments described elsewhere herein, the temperature of the surface ranges from 25° C. to 150° C., e.g., from 25° C. to 100° C., or from 25° C. to 90° C., or from 25° C. to 85° C., or from 25° C. to 80° C., or from 25° C. to 75° C., or from 25° C. to 70° C. In various embodiments described elsewhere herein, the temperature of the surface ranges from 30° C. to 150° C., e.g., from 30° C. to 100° C., or from 30° C. to 90° C., or from 30° C. to 85° C., or from 30° C. to 80° C., or from 30° C. to 75° C., or from 30° C. to 70° C. In various embodiments described elsewhere herein, the temperature of the surface ranges from 40° C. to 150° C., e.g., from 50° C. to 150° C., or from 60° C. to 150° C., or from 70° C. to 150° C., or from 80° C. to 150° C., or from 90° C. to 150° C., or from 100° C. to 150° C., or from 110° C. to 150° C. In various embodiments described elsewhere herein, the temperature of the surface ranges from 50° C. to 150° C., e.g., from 50° C. to 140° C., or from 50° C. to 130° C., or from 50° C. to 120° C., or from 50° C. to 110° C., or from 50° C. to 100° C., or from 50° C. to 90° C., or from 50° C. to 80° C. In various embodiments (and at a particular time during operation of the device or system) the temperature of the surface is at or below the boiling point of any of the one or more dielectric compounds of formula (I) of the thermal management system. In various embodiments, throughout the contacting, each of the one or more dielectric compounds of formula (I) does not reach its boiling point.

[0071] An embodiment of the method of the present disclosure is illustrated with reference to Figure 1. A thermal management circuit 100 is shown in a schematic cross-sectional side view in Figure 1. The thermal management circuit 100 includes a thermal management fluid 120 that circulates through the circuit and passes through a surface 142. The temperature of the surface 142 increases compared to the temperature of the thermal management fluid 120. As a result, thermal energy is absorbed from the surface 142 into the thermal management fluid 120.

[0072] In various embodiments as described elsewhere herein, the method includes generating thermal energy by operating an electrical component. For example, the thermal management circuit 100 is associated with an electrical component 140 that generates heat during operation. In various embodiments, the heat is generated as a factor of charging and discharging the electrical component. As will be appreciated by those skilled in the art, inefficiencies in the operation of the electrical component and resistance of the circuit generate heat as electrical current passes through the circuit and elements of the electrical component. For example, heat from the operation of the electrical component 140 increases the temperature of the surface 142, resulting in the transfer of thermal energy to the thermal management fluid 120. In other embodiments, the thermal energy is generated by a chemical reaction, such as an exothermic reaction, or by friction. In yet other embodiments, the thermal management fluid is cooled and absorbs thermal energy from a surface at ambient or slightly higher temperature.

[0073] In various embodiments as described elsewhere herein, the electrical component includes a battery system, a capacitor, an inverter, an electrical cable, a fuel cell, a motor, or a computer. For example, in various embodiments, the electrical component is a battery system including one or more electrochemical cells disposed within a housing. In other embodiments, the electrical component is one or more capacitors, such as an electrolytic capacitor or an electric double layer capacitor, e.g., a supercapacitor. In yet other embodiments, the electrical component is one or more fuel cells, such as a polymer electrolyte membrane fuel cell, a direct methanol fuel cell, an alkaline fuel cell, a phosphoric acid fuel cell, a molten carbonate fuel cell, a solid oxide fuel cell, or a reversible fuel cell. In various embodiments, the electrical component is an electric motor. In other embodiments, the electrical component is a computer, e.g., a personal computer or a server. Additionally, in other embodiments, the electrical component is a high power charging device.

[0074] The electrical components of the present invention can operate with direct current (DC) or alternating current (AC). In various embodiments as described elsewhere herein, the electrical components operate with DC or AC voltages greater than 48 V. In various embodiments as described elsewhere herein, the electrical components operate with DC or AC voltages greater than 100 V, greater than 200 V, or greater than 300 V.

[0075] In various embodiments as described elsewhere herein, the surface is a surface of an electrical component. For example, in FIG. 1, the housing 150 of the electrical component 140 contains a reservoir of thermal management fluid 120. Elements of the electrical component, including certain circuitry that generates heat, are immersed in the thermal management fluid 120, and the thermal management fluid absorbs thermal energy directly from the exterior surface 142 of the electrical component 140.

[0076] In various embodiments described elsewhere herein, the surface is an interior surface of a conduit. For example, Figure 2 shows a thermal management circuit 200 including an electrical component 240 that includes a plurality of individual units 244. In particular, the electrical component 240 is a battery that includes a plurality of electrochemical cells 244. The electrical component 240 further includes a conduit 246 that extends through the interior of the electrical component and between the electrochemical cells 244. As the electrical component generates thermal energy, the interior surface 242 of the conduit 246 heats up and the thermal energy is absorbed by the thermal management fluid 220.

[0077] In various embodiments as described elsewhere herein, the conduits pass through a housing that surrounds the electrical components. For example, the conduit 246 in the thermal management circuit 200 extends through an opening 252 in a housing 250 that surrounds the electrical components 240, thereby allowing the thermal management fluid 220 to be carried to other elements of the thermal management circuit 200.

[0078] Another aspect of the disclosure provides a battery system including a housing, one or more electrochemical cells disposed within the housing, a fluid pathway extending through the housing and in substantial thermal communication with the one or more electrochemical cells, and a thermal management fluid according to any of the above-described embodiments disposed within the fluid pathway. For example, the thermal management circuit 200 of FIG. 2 includes a battery system 210. The battery system includes a plurality of electrochemical cells 244 disposed within a housing 250. A conduit 246 forms a fluid pathway extending through the housing. A thermal management fluid 220 disposed within the conduit 246 is thereby disposed in thermal communication with the electrochemical cells 244. As the electrochemical cells 244 charge and discharge, they generate heat, which is absorbed by the thermal management fluid 220. In various embodiments, the electrochemical cells undergo a rapid charge that generates a large amount of heat. The high heat capacity of the thermal management fluid can absorb this large amount of heat as soon as it is generated.

[0079] In various embodiments, as described elsewhere herein, the fluid pathway is at least partially defined by a cavity in the housing. For example, in various embodiments, at least a portion of the fluid pathway is formed between the electrochemical cell and an inner wall of the housing, similar to fluid pathway 122 in component 140.

[0080] In various embodiments as described elsewhere herein, the fluid pathway is at least partially defined by at least one conduit disposed within the housing. For example, in battery system 210, conduit 246 provides fluid pathway 222 through housing 250.

[0081] In various embodiments described elsewhere herein, the electrochemical cell is a lithium-ion electrochemical cell, hi other embodiments, the electrochemical cell is a solid-state cell, a lithium-sulfur cell, a lithium iron phosphate cell, a lithium-ion polymer cell, a sodium-ion cell, an aluminum-ion cell, a lead-acid cell, or a magnesium-ion cell.

[0082] In various embodiments as described elsewhere herein, the battery system is a component of an electric vehicle. In some embodiments, the electric vehicle is a fully electric vehicle or a hybrid electric vehicle. In other embodiments, the battery system is a component of a power motor, e.g., an electric motor or a motor in power electronics. In other embodiments, the battery system is part of a stationary energy storage solution, e.g., a home energy storage solution that works in conjunction with a local renewable energy source, such as a solar panel or a wind turbine.

[0083] Another aspect of the present disclosure provides a thermal management circuit including a fluid path extending around and / or through a heat source, and a thermal management fluid according to any of the above-mentioned embodiments disposed within the fluid path and configured to circulate within the fluid path and absorb thermal energy generated by the heat source, the fluid being disposed within the fluid path, the heat exchanger, the pump, and the connecting ducts. For example, the thermal management circuit 100 shown in FIG. 1 includes a fluid path 122 extending around an electrical component 140. The thermal management fluid 120 flows through the path 122 and absorbs thermal energy from the electrical component 140. From the fluid path 122, the thermal management fluid 120 flows through a first duct 130 to a heat exchanger 160. Thermal energy stored in the thermal management fluid 120 is removed from the fluid in a heat exchanger 160 before the fluid flows through a second duct 132 to a pump 170. After the pump 170, the thermal management fluid 120 passes through a third duct 134 and returns to the fluid path 122 surrounding the electrical component 140. The circuit 100 shown in Figure 1 is a schematic diagram of a non-complex embodiment using the described thermal management fluid. In other embodiments, the thermal management circuit includes additional elements such as any combination of valves, pumps, heat exchangers, reservoirs, and ducts.

[0084] In various embodiments as described elsewhere herein, the heat source is a battery including a plurality of electrochemical cells, and the fluid path passes between at least two of the electrochemical cells.

[0085] In various embodiments as described elsewhere herein, the fluid path is defined by a housing around the electrical component. For example, the housing 150 in FIG. 1 surrounds the electrical component 140 and provides a cavity for the thermal management fluid 120. The electrical component 140 is held within the housing at a distance from the walls of the housing 150, which allows a path for the thermal management fluid 120 to be formed between the housing 150 and the electrical component 140. The housing 150 has a closed shape with certain openings 152 that provide access for the thermal management fluid 120, while in other embodiments the top of the housing is open and the thermal management fluid is held within the housing by gravity.

[0086] In various embodiments as described elsewhere herein, the fluid pathways are configured to place a thermal management fluid in substantial thermal communication with the electrical component to absorb thermal energy generated by the electrical component. For example, in thermal management circuit 100, fluid pathway 122 extends around electrical component 140 and is in direct contact with a surface of electrical component 140. Additionally, in thermal management circuit 200, fluid path 222 passes through conduit 246 that extends adjacent to elements of electrical component 240. In both cases, the fluid path places the thermal management fluid in close proximity to the electrical components such that the thermal management fluid readily absorbs thermal energy from the components.

[0087] In various embodiments as described elsewhere herein, the thermal management circuit further includes a heat exchanger in fluid communication with the fluid path, and the thermal management fluid is configured to circulate between the fluid path and the heat exchanger to dissipate heat through the heat exchanger. In various embodiments as described elsewhere herein, the heat exchanger is configured to remove heat from the thermal management fluid. For example, in the thermal management circuit 100, after the thermal management fluid 120 is pumped out of the housing 150, the thermal management fluid 110 proceeds to the heat exchanger 160 where the thermal energy is transferred to a cooler fluid, such as ambient air or a coolant.

[0088] In various embodiments as described elsewhere herein, the thermal management circuit includes a battery system according to any of the embodiments described above. For example, thermal management circuit 200 includes battery system 210. In various embodiments as described elsewhere herein, the thermal management circuit includes immobilized desiccant material arranged according to any of the embodiments described above. For example, thermal management circuit 300 includes battery desiccant material 360.

[0089] The details shown in this specification are presented by way of example and for the purpose of illustrative discussion of various embodiments of the present invention only, and are presented to provide what is believed to be the most useful and easily understood explanation of the principles and conceptual aspects of various embodiments of the present invention. In this regard, no attempt is made to show the structural details of the present invention in more detail than is necessary for a fundamental understanding of the present invention, and the description taken together with the figures and / or examples will make clear to those skilled in the art how some forms of the present invention can be embodied in practice. Thus, before the disclosed processes and devices are described, it should be understood that the aspects described herein are not limited to specific embodiments, apparatus, or configurations, and therefore may, of course, vary. It should also be understood that the terms used herein are intended to describe particular aspects only, and are not intended to be limiting unless specifically defined herein.

[0090] As used in the context of describing the present invention (particularly in the context of the embodiments and claims which follow), the terms "a," "an," "the," and similar referents are to be construed to encompass both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context.

[0091] The term "alkyl" as used herein means a straight or branched chain hydrocarbon containing 1 to 12 carbon atoms, unless otherwise specified. Representative examples of alkyl include, but are not limited to, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, 3-methylhexyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, n-heptyl, n-octyl, n-nonyl, and n-decyl. When an "alkyl" group is a linking group between two other moieties, it may be straight or branched, and examples include, but are not limited to, -CH2-, -CHaCH2-, -CH2CH2CHC(CH3)-, and -CH2 CH(CH2CH3)CH2-.

[0092] All methods described herein can be performed in any suitable order of steps unless otherwise indicated herein or clearly contradicted by context. Any and all examples provided herein, or the use of exemplary language (e.g., "etc.") are intended merely to better illuminate the invention and do not impose limitations on the scope of the invention as otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[0093] Throughout this specification and the claims, the word "comprise" means "comprise" unless the context clearly requires otherwise. "Comprising" and the like should be construed in an inclusive sense, i.e., "including, but not limited to," as opposed to an exclusive or exhaustive sense. Words using the singular or plural also include the plural and singular, respectively. Furthermore, the words "herein," "above," and "below," and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application.

[0094] As will be understood by one of ordinary skill in the art, each embodiment disclosed herein can comprise, consist essentially of, or consist of its particular described elements, steps, ingredients, or components. As used herein, the transitional phrases "comprise" or "comprises" mean including, but are not limited to, and allow for the inclusion of unspecified elements, steps, ingredients, or components, even if in large amounts. The transitional phrase "consisting of" excludes any unspecified elements, steps, ingredients, or components. The transitional phrase "consisting essentially of" limits the scope of the embodiment to the specified elements, steps, ingredients, or components, and those that do not materially affect the embodiment.

[0095] All percentages, ratios and proportions herein are by weight unless otherwise specified.

[0096] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values ​​set forth in the specific examples are reported as precisely as possible, however, any numerical value inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0082] Groupings of alternative elements or embodiments of the disclosure are not to be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. It is anticipated that one or more members of a group may be included in, or deleted from, a group for reasons of convenience and / or patentability. When any such inclusion or deletion occurs, the specification is deemed to include the group as modified and thus fulfill the written description of all Markush groups used in the appended claims.

[0097] Several embodiments of the various aspects of the present disclosure are described herein, including the best mode known to the inventors for carrying out the methods described herein. Of course, variations of these described embodiments will become apparent to those skilled in the art upon reading the foregoing description. Those skilled in the art may use such variations as necessary, and thus the methods of the present disclosure may be carried out in ways other than those specifically described herein. Accordingly, the scope of the present disclosure includes all modifications and equivalents of the subject matter described in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the present disclosure unless otherwise indicated herein or clearly contradicted by context. Working Example

[0098] The methods of the present disclosure are further illustrated by the following examples, which should not be construed as limiting the scope or spirit of the disclosure to the particular procedures and compounds described therein. Preparation of the Dielectric Compounds of Formula (I)

[0099] The compounds of the present disclosure can be readily prepared from inexpensive starting materials such as diols, as shown in Scheme 1.

[0100] [ka] wherein R 1-R 6, m, and n are as defined herein, R is R 1 or R 2 as defined herein, and L is a leaving group.

[0101] [ka]

[0102] To a solution of 2-((2-ethylhexyl)oxy)ethan-1-ol (151 g, 0.87 mol, 1.0 equiv.) in xylenes (30 mL) was added NaOH (38 g, 0.96 mol, 1.1 equiv.) in one portion. The resulting mixture was heated to 120 °C (internal temperature) and stirred for 30 min. The color of the reaction mixture changed from colorless to deep red-purple during this period. The reaction mixture was then treated with 2-ethylhexyl bromide (168 g, 0.87 mmol, 1.0 equiv.) dropwise over 5 min. The mixture was stirred at 120 °C for 1 h. The system was then subjected to vacuum (approximately 400 mbar) and a steady reflux of xylenes into the Dean-Stark receiver was initiated. The reaction was maintained for 4 h, after which 15 mL of water was collected. The reaction was returned to ambient pressure and temperature and diluted with water. The organic phase was separated and the aqueous phase was washed with heptane (3 x 50 mL). The organic phases were combined, dried over MgSO4, filtered and concentrated in vacuo. The crude product was purified by vacuum distillation at 2.5 mbar to give 1,2-bis((2-ethylhexyl)oxy)ethane (197 g, 0.69 mol, 79% yield).

[0103] The physical properties of 1,2-bis((2-ethylhexyl)oxy)ethane were evaluated and are shown in Table 2.

[0104] [Table 2]

[0105] [Table 3]

[0106] The advantages of 1,2-bis((2-ethylhexyl)oxy)ethane are more evident when compared directly with PAO 2 (e.g., DURASYN® 162 available from INEOS, Houston, Texas, US), the current standard in thermal management fluids. In particular, the viscosity of 1,2-bis((2-ethylhexyl)oxy)ethane is significantly lower than that of PAO 2 at key temperatures, i.e., 20° C. and 40° C., while the flash point is nearly the same. Thus, as a thermal management fluid, 1,2-bis((2-ethylhexyl)oxy)ethane provides good heat transfer but requires low pump power due to its ultra-low viscosity, while at the same time retaining an adequate flash point to prevent sparks in the event of failure of batteries or power electronics.

[0107] Other aspects of the present disclosure will be described in relation to the embodiments recited below, which can be combined in any manner and in any number that is not technically or logically consistent.

[0108] The first embodiment is a thermal management fluid. one or more dielectric compounds of formula (I)

[0109] [ka] m is an integer 1, 2, or 3; n is an integer 1, 2, 3, 4, 5, 6, 7, or 8; R1 is C6-C12 alkyl; R2 is a C6-C12 alkyl; Each Ra and R4 is independently selected from H and C1-C6 alkyl; each Rs and R is independently selected from H and C1-C6 alkyl; The one or more dielectric compounds are present in a total amount ranging from 1 wt. % to 100 wt. %, based on a total weight of the thermal management fluid. A thermal management fluid, wherein the thermal management fluid has a flash point of at least 100° C. as measured in accordance with ASTM D93, and wherein the thermal management fluid has a dielectric constant of at least 1.5 at 25° C.

[0110] Embodiment 2 relates to the thermal management fluid of embodiment 1, wherein each of the one or more compounds contains a total number of carbon atoms from 14 to 50 (e.g., 14 to 40, 14 to 30, 14 to 20, 16 to 50, 16 to 40, 16 to 30, 16 to 20, 18 to 50, 18 to 40, 18 to 30, 18 to 20, 20 to 50, 20 to 40, or 20 to 30).

[0111] Embodiment 3 is directed to the thermal management fluid of embodiment 1, wherein each of the one or more compounds contains a total number of carbon atoms from 18 to 22.

[0112] Embodiment 4 relates to the thermal management fluid of any of embodiments 1-3, wherein R 1 is a C 6-C 10 alkyl, such as a C 6-C 8 alkyl.

[0113] Embodiment 5 relates to the thermal management fluid of any of embodiments 1-3, wherein R 1 is a C 8 -C 12 alkyl, such as a C 8 -C 16 alkyl or a C 10 -C 12 alkyl.

[0114] Embodiment 6 is directed to the thermal management fluid of any of embodiments 1-3, wherein R1 is a branched C6-C12 alkyl, such as a branched C6-C10 alkyl, a branched C6-C8 alkyl, a branched C6-C12 alkyl, a branched C8-C10 alkyl, or a branched C10-C12 alkyl.

[0115] Embodiment 7 is directed to the thermal management fluid of embodiment 6, wherein the branch of R1 is alpha to the oxygen atom to which R1 is bonded.

[0116] Embodiment 8 relates to the thermal management fluid of any of embodiments 1-7, wherein R2 is a C6-C10 alkyl, such as a C6-C8 alkyl.

[0117] Embodiment 9 relates to the thermal management fluid of any of embodiments 1-7, wherein R2 is C 1-C 12 alkyl, such as C 1-C 10 alkyl or C 10-C 12 alkyl.

[0118] Embodiment 10 relates to the thermal management fluid according to any of the embodiments 1 to 7, wherein R2 is a branched C6 to C12 alkyl, such as a branched C6 to C10 alkyl, a branched C6 to C8 alkyl, a branched C8 to C12 alkyl, a branched C8 to C18 alkyl, or a branched C10 to C12 alkyl.

[0119] Embodiment 11 is directed to the thermal management fluid of embodiment 10, wherein the branch of R2 is at the 3-position relative to the oxygen atom to which R2 is bonded.

[0120]

[0043] Embodiment 12 relates to the thermal management fluid according to any of embodiments 1 to 11, wherein each of R3, R4, R5, and R6 is H, ie, the compound has the formula (I).

[0121] [ka]

[0122] Embodiment 13 is directed to the thermal management fluid of any of embodiments 1-11, wherein each of R4, R5, and R6 is H and Ra is a C1-C6 alkyl (such as methyl or ethyl), i.e., the compound has the formula:

[0123] [ka]

[0124] A fourteenth embodiment relates to the thermal management fluid of any one of the first to thirteenth embodiments, wherein n is an integer 1, 2, or 3, for example, n is an integer 1 or 2.

[0125] A fifteenth embodiment relates to the thermal management fluid of any one of the first to tenth embodiments. The one or more dielectric compounds have formulas 1-13, where n is 1, for example, the one or more dielectric compounds have formula

[0126] [ka]

[0127] Embodiment 16 is directed to the thermal management fluid of any of embodiments 1-13, wherein n is 2, eg, the one or more dielectric compounds have the formula (II).

[0128] [ka]

[0129] A seventeenth embodiment relates to the thermal management fluid of any of the first to sixteenth embodiments, wherein m is 1.

[0130] An eighteenth embodiment is directed to the thermal management fluid of any of the first to sixteenth embodiments, wherein m is an integer 1 or 2 and n is 1.

[0131] A nineteenth embodiment is directed to the thermal management fluid of any one of the first to third embodiments. m is an integer 1, 2, or 3; n is 1; R1 is C6-C12 alkyl; R2 is a C6-C12 alkyl; R3 is H or C1-C3 alkyl; R4, Rs and Re are independently H.

[0132] The twentieth embodiment is directed to the thermal management fluid of any one of the first to third embodiments. m is an integer 1, 2, or 3; n is 1; R 1 is C6-C10 alkyl; R2 is a C6-C8 alkyl; R3 is H or C1-C3 alkyl; R4, Rs and Re are independently H.

[0133] Embodiment 21 relates to the thermal management fluid according to embodiment 1, wherein the one or more compounds of formula (I) have the structure:

[0134] [ka] wherein each of Ra and Rb is independently methyl or ethyl, and each of Rc and Rd is independently C3-C8 alkyl, for example, C3-C7 alkyl or C3-C6 alkyl.

[0135] Embodiment 22 is directed to the thermal management fluid of embodiment 1, wherein the one or more compounds of formula (I) have the structure:

[0136] [ka] wherein each of Ra and Rb is independently methyl or ethyl, and each of Rc and Rd is independently C3-C6 alkyl, such as C3-C8 alkyl or C3-C7 alkyl.

[0137] Embodiment 23 relates to the thermal management fluid of embodiment 1, wherein the one or more compounds of formula (I) have the structure:

[0138] [ka] wherein each of Ra and Rb is independently methyl or ethyl, and each of Rc and Rd is independently C3-C8 alkyl, for example, C3-C7 alkyl or C3-C6 alkyl.

[0139] Embodiment 24 relates to the thermal management fluid of embodiment 1, wherein the one or more compounds of formula (I) have the structure:

[0140] [ka] wherein Ra and Rb are each independently methyl or ethyl, and Rc and Rd are each independently C3-C6 alkyl, such as C3-C8 alkyl or C3-C7 alkyl.

[0141] Embodiment 25 relates to the thermal management fluid of embodiment 1, wherein the one or more compounds of formula (I) have the structure:

[0142] [ka] wherein each of Ra and Rb is independently methyl or ethyl, and each of Rc and Rd is independently C3-C8 alkyl, for example, C3-C7 alkyl or C3-C6 alkyl.

[0143] Embodiment 26 relates to the thermal management fluid of any of embodiments 21-25, wherein each of Re and Ra is independently a C4-C6 alkyl.

[0144] Embodiment 27 is directed to the thermal management fluid of any of Embodiments 21 to 26, wherein m is 1.

[0145] Embodiment 28 relates to the thermal management fluid of embodiment 1, wherein the one or more dielectric compounds are independently selected from:

[0146] [ka]

[0147] [ka]

[0148] Embodiment 29 is directed to the thermal management fluid of embodiment 1, wherein the dielectric compound is

[0149] [ka] It is.

[0150] Embodiment 30 is directed to the thermal management fluid of any of embodiments 1-29, wherein the one or more dielectric compounds have a flash point, as measured according to ASTM D93, of at least 140° C. (e.g., at least 145° C., at least 150° C., at least 155° C., at least 160° C., or at least 165° C.).

[0151] Embodiment 31 relates to the thermal management fluid according to any of the preceding embodiments, wherein the one or more dielectric compounds have a kinematic viscosity at 40° C., measured according to ASTM D455, in the range of 1.5 to 20 cSt, e.g., 1.5 to 15 cSt, or 2 to 20 cSt, or 2 to 15 cSt, or 3 to 20 cSt, or 3 to 15 cSt, or 5 to 20 cSt, or 5 to 15 cSt.

[0152] Embodiment 32 relates to the thermal management fluid of any of the preceding embodiments, wherein the one or more dielectric compounds have a kinematic viscosity at 40° C. in the range of 1.5 to 10 cSt, e.g., 1.5 to 8 cSt, or 1.5 to 6 cSt, or 2 to 10 cSt, or 2 to 8 cSt, or 2 to 6 cSt, or 3 to 10 cSt, or 3 to 8 cSt, or 3 to 6 cSt, or 5 to 10 cSt, or 5 to 8 cSt, or 5 to 6 cSt, or 6 to 10 cSt, or 8 to 10 cSt, measured according to ASTM D455.

[0153] Embodiment 33 relates to the thermal management fluid of any of embodiments 1-30, wherein the one or more dielectric compounds have a kinematic viscosity at 40° C. in the range of 1.5 to 5 cSt, or 1.5 to 4 cSt, or 1.5 to 3 cSt, or 2 to 5 cSt, or 2 to 4 cSt, or 2 to 3 cSt, or 3 to 5 cSt, or 3 to 4 cSt, or 4 to 5 cSt, measured according to ASTM D455.

[0154] Embodiment 34 relates to a thermal management fluid according to any of embodiments 1 to 33, wherein the one or more dielectric compounds are present in an amount ranging from 5 wt. % to 100 wt. %, or from 10 wt. % to 100 wt. %, or from 20 wt. % to 100 wt. %, based on the total weight of the thermal management fluid.

[0155] Embodiment 35 relates to a thermal management fluid according to any of embodiments 1 to 33, wherein the one or more dielectric compounds are present in an amount ranging from 50% to 100% by weight, for example, from 75% to 100% by weight, or from 85% to 100% by weight, or from 90% to 100% by weight, or from 95% to 100% by weight, or from 98% to 100% by weight, based on the total weight of the thermal management fluid.

[0156]

[0043] Embodiment 36 relates to a thermal management fluid according to any of embodiments 1 to 33, wherein the one or more dielectric compounds are present in an amount ranging from 1 wt% to 99.9 wt% (e.g., from 5 wt% to 99.9 wt%, or from 10 wt% to 99.9 wt%, or from 20 wt% to 99.9 wt%), or from 50 wt% to 99.9 wt%, for example, from 75 wt% to 99.9 wt%, or from 85 wt% to 99.9 wt%, or from 90 wt% to 99.9 wt%, or from 95 wt% to 99.9 wt%, or from 98 wt% to 99.9 wt%, based on the total weight of the thermal management fluid.

[0157] Embodiment 37 is directed to the thermal management fluid of any of embodiments 1-33, wherein the one or more dielectric compounds are present in an amount ranging from 1 wt. % to 99 wt. % (e.g., from 5 wt. % to 99 wt. %, or from 10 wt. % to 99 wt. %, or from 20 wt. % to 99 wt. %), or from 50 wt. % to 99 wt. %, for example, from 80 wt. % to 99 wt. %, or from 85 wt. % to 99 wt. %, or from 90 wt. % to 99 wt. %, or from 95 wt. % to 99 wt. %, based on a total weight of the thermal management fluid.

[0158] Embodiment 38 is directed to the thermal management fluid of any of embodiments 1-33, wherein the one or more dielectric compounds are present in an amount ranging from 1 wt. % to 95 wt. % (e.g., 5 wt. % to 95 wt. %, or 10 wt. % to 95 wt. %, or 20 wt. % to 95 wt. %), or 50 wt. % to 95 wt. %, for example, 75 wt. % to 95 wt. %, or 85 wt. % to 95 wt. %, or 1 wt. % to 85 wt. % (e.g., 5 wt. % to 85 wt. %, or 10 wt. % to 85 wt. %, or 20 wt. % to 85 wt. %), or 50 wt. % to 85 wt. %, for example, 65 wt. % to 85 wt. %, or 75 wt. % to 85 wt. %, based on a total weight of the thermal management fluid.

[0159] Embodiment 39 relates to the thermal management fluid of any of embodiments 1-38, further comprising a Group II, Group III, Group IV, or Group V base oil.

[0160] Embodiment 40 is directed to the thermal management fluid of any of embodiments 1-38, further comprising a Group II or Group III base oil.

[0161] Embodiment 41 is directed to the thermal management fluid of any of embodiments 1-38, further comprising a Group IV base oil (such as a polyalphaolefin (PAO)).

[0162] Embodiment 42 relates to a thermal management fluid according to any of embodiments 1-38, further comprising an ester base oil stock.

[0163] Embodiment 43 relates to the thermal management fluid of any of the preceding embodiments, further comprising one or more of a corrosion inhibitor, an antioxidant (such as phenolic and aminic antioxidants), a pour point depressant, an antifoam agent, a defoamer, a viscosity index modifier, a preservative, a biocide, a surfactant, a seal swell additive, a flame retardant, and combinations thereof, e.g., in an amount up to 0.5 wt.%, up to 1.0 wt.%, or up to 5.0 wt.%.

[0164] Embodiment 44 relates to the thermal management fluid of any of embodiments 1-41, further comprising one or more flame retardants, for example in an amount up to 20 wt.%, up to 10 wt.%, or up to 5 wt.%.

[0165] Embodiment 45 is directed to the thermal management fluid of any of embodiments 1-44, wherein the thermal management fluid has a flash point, measured according to ASTM D93, of at least 110° C., e.g., at least 120° C., at least 125° C., at least 130° C., or at least 135° C.

[0166] Embodiment 46 is directed to the thermal management fluid of any of embodiments 1-44, wherein the thermal management fluid has a flash point, measured according to ASTM D93, of at least 140° C., e.g., at least 145° C., at least 150° C., or at least 150° C.

[0167] Embodiment 47 relates to the thermal management fluid of any of the preceding embodiments, having a kinematic viscosity at 40° C. in the range of 2 to 20 cSt, e.g., 2 to 15 cSt, or 3 to 20 cSt, or 3 to 15 cSt, or 5 to 20 cSt, as measured according to ASTM D455.

[0168] Embodiment 48 relates to the thermal management fluid of any of the preceding embodiments, having a kinematic viscosity at 40° C. in the range of 2 to 10 cSt, e.g., 2 to 8 cSt, or 2 to 6 cSt, or 3 to 10 cSt, or 3 to 8 cSt, or 3 to 6 cSt, or 5 to 10 cSt, or 5 to 8 cSt, or 5 to 6 cSt, or 6 to 10 cSt, or 8 to 10 cSt, as measured according to ASTM D455.

[0169] Embodiment 49 relates to the thermal management fluid of any of the preceding embodiments having a kinematic viscosity at 40° C. in the range of 2-5 cSt, or 2-4 cSt, or 2-3 cSt, or 3-5 cSt, or 3-4 cSt, or 4-5 cSt, as measured according to ASTM D455.

[0170] Embodiment 50 relates to the thermal management fluid of any of embodiments 1-49 having a dielectric constant, measured at 25° C., of at least 1.75, such as at least 2.0, or at least 2.25.

[0171] Embodiment 51 relates to the thermal management fluid of any of embodiments 1 to 49, having a dielectric constant in the range of 1.5 to 10, or 1.8 to 10, or 1.5 to 2.8, or 1.8 to 2.8.

[0172] Embodiment 52 relates to the thermal management fluid of any of embodiments 1-51, having a density of 1.1 g / cm3 or less at 25° C. (eg, 1 g / cm3 or less at 25° C.).

[0173] Embodiment 53 is directed to the thermal management fluid of any of embodiments 1 to 52, having a thermal conductivity in the range of 0.05 W / m·K to 1 W / m·K at 25° C.

[0174] Embodiment 54 relates to a thermal management fluid according to any of embodiments 1 to 53 having a specific heat capacity of at least 1 J / g·K (e.g., at least 1.2 J / g·K, or at least 1.5 J / g·K at 25° C.).

[0175] A fifty-fifth embodiment relates to a thermal management fluid according to any of the first to fifty-second embodiments, having a coefficient of thermal expansion of 1100×10 −6 / K or less (eg, 1050×10 −6 / K or less, or 1000×10 −6 / K or less).

[0176]

[0023] Embodiment 56 is a method comprising: Contacting the thermal management fluid of any one of embodiments 1 to 55 with a surface having a temperature of at least 25° C., the surface being in substantial thermal communication with a heat source. absorbing thermal energy from the heat source through the surface of the thermal management fluid;

[0177] Embodiment 57 relates to a method according to embodiment 56, wherein the surface has a temperature of at least 30°C, such as at least 40°C.

[0178] Embodiment 58 relates to a method according to embodiment 56, wherein the surface has a temperature in the range of 25°C to 150°C, e.g., 25°C to 100°C, or 25°C to 90°C, or 25°C to 85°C, or 25°C to 80°C, or 25°C to 75°C, or 25°C to 70°C.

[0179] Embodiment 59 relates to a method according to embodiment 56, wherein the surface has a temperature in the range of 30°C to 150°C, e.g., 30°C to 100°C, or 30°C to 90°C, or 30°C to 85°C, or 30°C to 80°C, or 30°C to 75°C, or 30°C to 70°C; or 40°C to 150°C, e.g., 50°C to 150°C, or 60°C to 150°C, or 70°C to 150°C, or 80°C to 150°C, or 90°C to 150°C, or 100°C to 150°C, or 110°C to 150°C.

[0180] Embodiment 60 relates to a method according to embodiment 56, wherein the surface has a temperature in the range of 50°C to 150°C, for example, 50°C to 140°C, or 50°C to 130°C, or 50°C to 120°C, or 50°C to 110°C, or 50°C to 100°C, or 50°C to 90°C, or 50°C to 80°C.

[0181] Embodiment 61 is directed to a method according to any of embodiments 56 to 60, wherein the thermal management fluid is a stationary (ie, non-circulating) body of fluid.

[0182] Embodiment 62 relates to the method of any one of embodiments 56 to 60, wherein the contacting is performed by circulating a thermal management fluid over the surface.

[0183] Embodiment 63 relates to the method of any one of embodiments 56 to 60, wherein the contacting is performed by circulating a thermal management fluid between the heat exchanger and the surface.

[0184] Embodiment 64 relates to the method of any one of embodiments 56 to 63, wherein the heat source is a working electrical component.

[0185] Embodiment 65 relates to the method of any of embodiments 56 to 63, wherein the heat source is a battery pack, a capacitor, an inverter, an electric cable, a fuel cell, a motor, a computer, or a high-power charging device.

[0186] Embodiment 66 relates to the method of any of embodiments 56 to 63, wherein the heat source is an electrochemical cell.

[0187] Embodiment 67 relates to the method of embodiment 66, wherein the electrochemical cell is selected from a solid-state electrochemical cell, a lithium-sulfur electrochemical cell, a lithium iron phosphate electrochemical cell, a lithium ion polymer electrochemical cell, a sodium ion electrochemical cell, an aluminum-ion cell, a lead-acid cell, and a magnesium ion cell.

[0188] Embodiment 68 relates to the method of any one of embodiments 56 to 67, wherein the surface is an interior surface of a conduit in substantial thermal communication with the heat source.

[0189] Embodiment 69 is directed to the method of embodiment 68, in which the conduit passes through a housing that surrounds the electrical component.

[0190] Embodiment 70 is directed to a battery system. Housing and one or more electrochemical cells disposed within the housing; a fluid pathway extending within the housing and in substantial thermal communication with the one or more electrochemical cells; A thermal management fluid according to any one of embodiments 1 to 55 disposed in the fluid path.

[0191] Embodiment 71 relates to the battery system of embodiment 70, wherein the electrochemical cell is a lithium ion electrochemical cell.

[0192] Embodiment 72 is directed to the battery system of embodiment 70, in which the electrochemical cell is a solid-state electrochemical cell, a lithium-sulfur electrochemical cell, or a lithium-sulfur electrochemical cell. The cell may be a lithium iron phosphate electrochemical cell, a lithium ion polymer electrochemical cell, a sodium ion electrochemical cell, an aluminum ion cell, a lead acid cell, or a magnesium ion cell.

[0193] The seventy-third embodiment relates to an electric vehicle equipped with the battery system of any one of the seventieth to seventy-second embodiments.

[0194] The seventy-third embodiment is directed to a thermal management circuit, the thermal management circuit comprising: a fluid path extending around and / or through the heat source; A thermal management fluid according to any one of the preceding claims, disposed within the fluid path and configured to circulate within the fluid path and absorb thermal energy generated by the heat source. The fluid is disposed in the fluid path, the heat exchanger, the pump, and the connecting duct.

[0195] Embodiment 74 is directed to a method for preparing the thermal management fluid of any of embodiments 1 to 55, comprising: Compound of formula (II)

[0196] [ka] m is an integer 1, 2, or 3; n is an integer 1, 2, 3, 4, 5, 6, 7, or 8; R3, R4, Rs and Re are each independently selected from H and C1-C6 alkyl, reacting with (C6-C12 alkyl)-L, where L is a leaving group, to obtain a dielectric compound of formula (I).

[0197] Embodiment 75 relates to the method of embodiment 74, wherein the contacting of the compound of Formula (II) with (C6-C12 alkyl)-L is in the presence of a catalyst.

[0198] Embodiment 76 is directed to the method of embodiment 73 or 74, further comprising mixing the dielectric compound in an amount ranging from 1 wt. % to 99.9 wt. %, based on the total weight of the thermal management fluid, with one or more of a base oil, a corrosion inhibitor, an antioxidant (such as phenolic and aminic antioxidants), a pour point depressant, an antifoam agent, a defoamer, a viscosity index modifier, a preservative, a biocide, a surfactant, a seal swell additive, a flame retardant, and combinations thereof.

[0199] Finally, it should be understood that the various embodiments herein are illustrative of the methods of the present disclosure. Other modifications that may be employed are within the scope of the present disclosure. Thus, by way of example, and not of limitation, alternative configurations of the methods may be utilized in accordance with the teachings of the present disclosure. Thus, the methods of the present disclosure are not limited to that precisely as shown and described.

Claims

1. A thermal management fluid is contacted with a surface having a temperature of at least 25°C, the surface being in substantial thermal communication with a heat source; Thermal energy is absorbed from a heat source through the surface into the thermal management fluid, the thermal management fluid consisting of one or more dielectric compounds of formula (I) 【Chemistry 1】 During the ceremony, m is an integer 1, 2, or 3; n is an integer 1, 2, 3, 4, 5, 6, 7, or 8; R 1 is C 6 ~C 12 is alkyl; R 2 is C 6 ~C 12 is alkyl; Each R 3 and R 4 are independently H and C 1 ~C 6 alkyl; Each R 5 and R 6 are independently H and C 1 ~C 6 alkyl; the one or more dielectric compounds are present in a total amount ranging from 1 wt. % to 100 wt. %, based on the total weight of the thermal management fluid; A method of thermal fluid management, wherein the thermal management fluid has a flash point of at least 100°C measured in accordance with ASTM D93 and a dielectric constant of at least 1.5 at 25°C.

2. The method of claim 1, wherein each of the one or more compounds contains a total number of carbon atoms from 14 to 50.

3. R 1 C 6 ~C 10 is alkyl, R 2 C 6 ~C 10 3. The method according to claim 1 or 2, wherein the alkyl group is an alkyl group.

4. R 2 and / or R 2 But R 2 The method according to any one of claims 1 to 3, wherein said compound is at the β position relative to the oxygen atom to which said compound is bonded.

5. R 3 , R 4 , R 5 , and R 6 is H, i.e., the compound has the formula: 【Chemistry 2】 or R 4 , R 5 , and R 6 Each of is H and R 3 is C 1 ~C 6 alkyl (such as methyl or ethyl), i.e., the compound has the formula 【Chemistry 3】 The method according to any one of claims 1 to 4.

6. The method according to any one of claims 1 to 5, wherein m is 1.

7. One or more compounds of formula (I) have the structure: 【Chemistry 4】 In the formula, Ra and Rb are each independently methyl or ethyl, and Rc and Rd are each independently C 3 ~C 8 Alkyl, e.g., C 3 ~C 7 Alkyl or C 3 ~C 6 is alkyl, One or more compounds of formula (I) have the structure 【Chemistry 5】 In the formula, Ra and Rb are each independently methyl or ethyl, and Rc and Rd are each independently C 3 to C8 alkyl, for example C3 to C7 alkyl or C3 to C6 alkyl; One or more compounds of formula (I) have the structure 【Chemistry 6】 In the formula, Ra and Rb are each independently methyl or ethyl, and Rc and Rd are each independently C 3 ~C 8 alkyl, for example C 3 -C 7 alkyl or C 3 -C 6 alkyl; One or more compounds of formula (I) have the structure 【Chemistry 7】 In the formula, Ra and Rb are each independently methyl or ethyl, and Rc and Rd are each independently C 3 to C8 alkyl, for example C3 to C7 alkyl or C3 to C6 alkyl; and / or One or more compounds of formula (I) have the structure 【Chemistry 8】 In the formula, Ra and Rb are each independently methyl or ethyl, and Rc and Rd are each independently C 3 ~C 8 Alkyl, for example, C 3 -C 7 alkyl or C 3 ~C 6 The method according to claim 1, wherein the alkyl group is an alkyl group.

8. The one or more dielectric compounds independently comprise: 【Chemistry 9】 2. The method of claim 1, selected from:

9. The method according to any one of the preceding claims, wherein the one or more dielectric compounds are present in an amount ranging from 50% to 99.9% by weight.

10. The method of claim 1, wherein the thermal management fluid has a flash point of at least 140° C. as measured in accordance with ASTM D93.

11. The method of any one of claims 1 to 10, wherein the thermal management fluid has a kinematic viscosity at 40°C in the range of 1.5 to 20 cSt, all measured according to ASTM D455.

12. A method according to any one of claims 1 to 11, wherein the surface has a temperature in the range of 50°C to 150°C.

13. The method of any one of claims 1 to 12, wherein the heat source is a working electrical component, such as a battery pack, a capacitor, an inverter, an electrical cable, a fuel cell, a motor, a computer, or a high power charging device.

14. A battery system comprising: Housing and one or more electrochemical cells disposed within the housing; a fluid pathway extending within the housing and in substantial thermal communication with the one or more electrochemical cells; a thermal management fluid disposed in the fluid path, comprising one or more dielectric compounds of formula (1) 【Chemistry 10】 During the ceremony, m is an integer 1, 2, or 3; n is an integer 1, 2, 3, 4, 5, 6, 7, or 8; R 1 is C 6 -C 12 alkyl; R2 is C6-C12 alkyl; each R 3 and R 4 is independently selected from H and C 1 -C 6 alkyl; each R 5 and R 6 is independently selected from H and C 1 -C 6 alkyl; one or more dielectric compounds are present in a total amount ranging from 1 wt. % to 100 wt. %, based on the total weight of the thermal management fluid; A battery system wherein the thermal management fluid has a flash point of at least 100°C measured in accordance with ASTM D93, and wherein the thermal management fluid has a dielectric constant of at least 1.5 at 25°C.

15. A thermal management circuit comprising: a fluid path extending around and / or through the heat source; a thermal management fluid disposed within the fluid path and configured to circulate within the fluid path and absorb thermal energy generated by the heat source; The fluid is disposed in the fluid path, the heat exchanger, the pump, and the connecting duct; The thermal management fluid comprises: consisting of one or more dielectric compounds of formula (I) 【Chemistry 11】 During the ceremony, m is an integer 1, 2, or 3; n is an integer 1, 2, 3, 4, 5, 6, 7, or 8; R 1 is C 6 -C 12 alkyl; R2 is C6-C12 alkyl; each R 3 and R 4 is independently selected from H and C 1 -C 6 alkyl; each R 5 and R 6 is independently selected from H and C 1 -C 6 alkyl; one or more dielectric compounds are present in a total amount ranging from 1 wt. % to 100 wt. %, based on the total weight of the thermal management fluid; A thermal management circuit, wherein the thermal management fluid has a flash point of at least 100°C as measured in accordance with ASTM D93 and a dielectric constant of at least 1.5 at 25°C.

16. A dielectric material comprising one or more dielectric compounds of formula (I): 【Chemistry 12】 During the ceremony, m is an integer 1, 2, or 3; n is an integer 1, 2, 3, 4, 5, 6, 7, or 8; R 1 is C 6 -C 12 alkyl; R2 is C6-C12 alkyl; each R 3 and R 4 is independently selected from H and C 1 -C 6 alkyl; each R 5 and R 6 is independently selected from H and C 1 -C 6 alkyl; one or more dielectric compounds are present in a total amount ranging from 1 wt. % to 100 wt. %, based on the total weight of the thermal management fluid; A thermal management fluid having a flash point of at least 100°C as measured in accordance with ASTM D93 and a dielectric constant of at least 1.5 at 25°C.

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