Thermal conditioning of a battery by immersion in a liquid composition

Abstract

The present invention relates to the use of a heat transfer composition for regulating the temperature of a battery, said heat transfer composition comprising greater than 0 to 40 weight percent of a coolant comprising a compound selected from the group consisting of halogenated hydrocarbons, perhalogenated compounds, fluoroketones, fluoroethers, and combinations thereof, and 60 to less than 100 weight percent of a dielectric fluid, said battery comprising an energy storage cell immersed in a heat transfer composition in a liquid state, and said heat transfer composition undergoing substantially no state change.

Description

Technical Field

[0001] This invention relates to the use of a heat transfer composition comprising at least one refrigerant and at least one dielectric fluid for regulating battery temperature. The invention is particularly applicable to batteries for electric or hybrid vehicles. Background Technology

[0002] In a variety of applications, especially in battery cooling, the need to dissipate high heat flux is essential.

[0003] In particular, batteries in electric or hybrid vehicles exhibit maximum efficiency under specific operating conditions, especially within very specific temperature ranges. Therefore, the driving range of electric or hybrid vehicles becomes an issue in cold climates, especially since high heating requirements consume a significant portion of the stored electrical energy. Furthermore, the usable power of the battery is low at low temperatures, posing driving challenges. Additionally, the cost of the battery significantly contributes to the overall cost of electric or hybrid vehicles.

[0004] Conversely, battery cooling is a primary safety concern. Various dielectric oils can be used to cool batteries in electric or hybrid vehicles. However, when rapid charging of the battery is required, dielectric oil alone is insufficient for effective cooling. In this case, fluids with higher volatility and lower viscosity are needed. However, these fluids typically have higher vapor pressures than those observed with dielectric oils, which may necessitate reinforcing the battery casing (and thus increasing its weight) to withstand the pressure. Furthermore, these fluids are more expensive than dielectric oils.

[0005] In addition, it is important to use compositions that are only slightly flammable or non-flammable near the battery to eliminate any safety risks associated with the use of these compositions.

[0006] Document FR 2 973809 relates to the use of zeolite adsorbents to improve the thermal stability of oils subjected to temperature changes in coolant fluid compositions.

[0007] Document FR 2 962442 relates to stable compositions containing 2,3,3,3-tetrafluoropropylene for use in refrigeration and air conditioning.

[0008] Document US 2014 / 057826 relates to heat transfer compositions comprising at least one hydrochlorofluoroolefin, said at least one hydrochlorofluoroolefin being used in air conditioning, refrigeration and heat pump applications or for cleaning products, components, substrates or other articles containing substances to be cleaned.

[0009] Document WO 2019 / 242977 relates to fluid-insulated switchgear, which includes a fluid compartment filled with an electrically insulating fluid and an electrical conductor located in the fluid compartment and electrically insulated by the electrically insulating fluid.

[0010] Document WO 2019 / 162598 relates to the use of refrigerants containing 2,3,3,3-tetrafluoropropylene for maintaining the temperature of batteries in electric or hybrid vehicles within a certain temperature range.

[0011] Document WO 2019 / 162599 relates to the use of refrigerants containing 2,3,3,3-tetrafluoropropylene for preheating the batteries of electric or hybrid vehicles during vehicle startup.

[0012] Document WO 2019 / 197783 relates to a process for cooling and / or heating a body or fluid in a motor vehicle by means of a system comprising a vapor compression circuit (in which a first heat transfer composition circulates) and a secondary circuit (in which a second heat transfer composition circulates).

[0013] Documents WO 2020 / 011888, WO 2020 / 100152, WO 2020 / 007954, US 9,865,907, US 10,784,545, FR 3037727, FR 3075471, FR 3085542, FR 3085545, FR 3085547, FR 3085556 and EP3 499 634 describe systems for thermally regulating batteries through direct contact with fluids.

[0014] It is necessary to ensure the optimal operation of batteries, especially those in electric or hybrid vehicles, in order to provide safe and efficient batteries with long lifespans without increasing costs. Summary of the Invention

[0015] The present invention relates first to the use of a heat transfer composition for regulating battery temperature, the heat transfer composition comprising more than 0 wt% to 40 wt% of a refrigerant and 60 wt% to less than 100 wt% of a dielectric fluid, the refrigerant comprising a compound selected from halogenated hydrocarbons, perhalogenated compounds, fluoroketones, fluoroethers, and combinations thereof, the battery comprising an energy storage cell immersed in the heat transfer composition in a liquid state, and the heat transfer composition substantially not undergoing a change of state.

[0016] In some embodiments, the heat transfer composition circulates in a heat transfer loop.

[0017] In some embodiments, the battery includes one or more modules, each module including a housing in which an energy storage unit battery is disposed, the housing forming part of the heat transfer loop.

[0018] In some embodiments, the heat transfer circuit is thermally coupled to a secondary circuit containing an additional transfer composition.

[0019] In some implementations, the secondary circuit is the vehicle's air conditioning circuit and / or a reversible heat pump circuit.

[0020] In some embodiments, the refrigerant comprises or is 1-chloro-3,3,3-trifluoropropylene, preferably in the E form, or is a binary mixture, preferably an azeotropic binary mixture, of 1,1,1,2,3-pentafluoropropane and 1-chloro-3,3,3-trifluoropropylene in the Z form, or of 1,1,1,4,4,4-hexafluorobut-2-ene in the Z form and 1,2-dichloroethylene in the E form.

[0021] In some embodiments, the dielectric fluid is selected from mineral dielectric oils, synthetic dielectric oils, and vegetable dielectric oils, and is preferably selected from aromatic hydrocarbons, poly(α-)olefins, and polyol esters, wherein the aromatic hydrocarbons are selected from alkylbenzenes, alkyl diphenyl ethanes, alkyl naphthalenes, methyl poly(poly)aryl methanes, and combinations thereof.

[0022] In some embodiments, this purpose is for cooling the battery. In some embodiments, the battery is a battery for an electric or hybrid vehicle, preferably a battery for an electric or hybrid automobile.

[0023] In some implementations, this use is carried out during the charging of the vehicle's battery, which is preferably fully charged within a period of less than or equal to 30 minutes, and more preferably less than or equal to 15 minutes, from the start of its complete discharge.

[0024] The present invention also relates to battery assemblies, particularly battery assemblies for electric or hybrid vehicles, the battery assembly comprising one or more modules, each module comprising a housing in which an energy storage cell battery is disposed, the housing being immersed in a heat transfer composition in a liquid state, the heat transfer composition comprising greater than 0 wt% to 40 wt% of a refrigerant and 60 wt% to less than 100 wt% of a dielectric fluid, the refrigerant comprising a compound selected from halogenated hydrocarbons, fully halogenated compounds, fluoroketones, fluoroethers, and combinations thereof, and the battery assembly being configured such that the heat transfer composition substantially does not undergo a change of state in order to regulate the temperature of the battery.

[0025] In some embodiments, the component includes a heat transfer loop in which a heat transfer composition circulates, and the module housing is incorporated into the heat transfer loop.

[0026] In some embodiments, the heat transfer circuit includes a pump; and / or the heat transfer circuit includes a heat exchanger to enable heat exchange between the heat transfer composition and the heat transfer composition in ambient air or a secondary circuit.

[0027] In some embodiments, the refrigerant comprises or is 1-chloro-3,3,3-trifluoropropylene, preferably in the E form, or is a binary mixture, preferably an azeotropic binary mixture, of 1,1,1,2,3-pentafluoropropane and 1-chloro-3,3,3-trifluoropropylene in the Z form, or of 1,1,1,4,4,4-hexafluorobut-2-ene in the Z form and 1,2-dichloroethylene in the E form.

[0028] In some embodiments, the dielectric fluid is selected from mineral dielectric oils, synthetic dielectric oils, and vegetable dielectric oils, and is preferably selected from aromatic hydrocarbons, poly(α-)olefins, and polyol esters, wherein the aromatic hydrocarbons are selected from alkylbenzenes, alkyl diphenyl ethanes, alkyl naphthalenes, methyl polyaryl methanes, and combinations thereof.

[0029] The present invention also relates to a method for regulating the battery temperature of the above-mentioned battery assembly, the method comprising heating the energy storage unit battery by means of the heat transfer composition without substantially any change in the state of the heat transfer composition and / or cooling the energy storage unit battery by means of the heat transfer composition.

[0030] This invention enables the fulfillment of the aforementioned needs. Specifically, it ensures optimal operation of devices, particularly batteries (especially traction batteries) in electric or hybrid vehicles, to provide safe and efficient batteries with long lifespans without increasing costs.

[0031] This is achieved by using a heat transfer composition comprising more than 0% to 40% by weight of a refrigerant and 60% to less than 100% of a dielectric fluid, wherein the refrigerant is selected from halogenated hydrocarbons, fully halogenated compounds, fluoroketones, fluoroethers, and combinations thereof, wherein the energy storage unit of the battery is immersed in the heat transfer composition in a liquid state, and wherein the heat transfer composition substantially does not undergo a change of state.

[0032] The phrase "substantially does not undergo any change of state" is understood to mean that the composition does not undergo any change of state, except for possible changes due to its vapor pressure as a function of temperature. Specifically, any change of state due to vapor pressure changes preferably involves less than 1% by weight, more preferably less than 0.5% by weight of the composition.

[0033] Preferably, the refrigerant has a boiling point below 50°C, more preferably below 30°C, and especially below 25°C or 20°C (at 1 bar).

[0034] Specifically, the combination of dielectric fluid and refrigerant allows for the provision of compositions that are not very viscous (especially compared to compositions composed of dielectric fluid), which, for example, reduces the energy consumption of the system. Preferably, heat transfer is therefore more efficient than using dielectric fluid alone.

[0035] In addition, the presence of compounds with low boiling points can help slow the spread of thermal runaway in the event of battery runaway.

[0036] Compared to using refrigerant alone, this invention enables reduced costs and weight without significantly degrading battery performance, lifespan, or safety.

[0037] In addition, the vapor pressure of the composition is generally lower than that of the refrigerant alone, which reduces the constraints on the reinforcement of the unit (device).

[0038] Therefore, the present invention enables a general increase in battery efficiency, lifespan, and safety, especially during fast charging, without increasing cost.

[0039] Preferably, the composition has a concentration of 10 or higher at 25°C. 6 The volume resistivity is Ω·cm. Preferably, the composition exhibits a breakdown voltage greater than or equal to 20 kV at 20°C. From a safety perspective, this ensures that the dielectric properties of the composition are compatible with direct contact cell battery use.

[0040] Advantageously, the combination of refrigerant and dielectric fluid also makes it possible to obtain compositions that are only slightly flammable or non-flammable. Attached Figure Description

[0041] [ Figure 1 [Illustration 1] is a diagram illustrating an embodiment of a battery assembly according to the present invention.

[0042] [ Figure 2 [Illustration 1] is a diagram illustrating an embodiment of a battery assembly according to the present invention.

[0043] [ Figure 3 [Illustration 1] is a diagram illustrating an embodiment of a battery assembly according to the present invention.

[0044] [ Figure 4 [Illustration 1] is a diagram illustrating an embodiment of a battery assembly according to the present invention.

[0045] [ Figure 5 [This is a graph showing the change in liquid saturation temperature of the heat transfer composition as a function of refrigerant content at a pressure of 1 bar (see the Examples section below). Temperature is shown on the y-axis (°C), and the dielectric fluid content is shown on the x-axis (wt%).

[0046] [ Figure 6 This is a graph showing the temperature changes within the casing of a cell containing a cell immersed in fluid, where one cell is experiencing thermal runaway. Temperature is represented on the y-axis (°C), and time is represented on the x-axis (s). Detailed Implementation

[0047] The invention will now be described in more detail and in a non-limiting manner in the following description.

[0048] Heat transfer composition

[0049] The heat transfer composition according to the invention comprises at least one refrigerant and at least one dielectric fluid.

[0050] The term "refrigerant" refers to a fluid that can absorb heat by evaporating at low temperatures and low pressures and can release heat by condensing at high temperatures and high pressures.

[0051] The refrigerant contains compounds selected from halogenated hydrocarbons, fully halogenated compounds, fluoroketones, fluoroethers, and combinations thereof.

[0052] The refrigerant may consist of one or more such compounds. Alternatively, it may also contain one or more other compounds selected from hydrocarbons (alkanes or alkenes, particularly propane, butane, isobutane, pentane, isopentane), CO2, and oxygen-containing hydrocarbons (particularly methoxymethane, ethoxyethane, and methyl formate).

[0053] Preferably, the refrigerant consists of C1, C2, C3, C4 and / or C5 compounds; more preferably, C1, C2, C3 and / or C4 compounds.

[0054] Among halogenated hydrocarbons, hydrofluorocarbons, hydrochlorofluorocarbons, hydrofluoroolefins, hydrochloroolefins, and hydrochlorofluoroolefins may be mentioned.

[0055] For example, the refrigerant can be selected from: 1,1,1,4,4,4-hexafluorobut-2-ene (HFO-1336mzz, E or Z isomer), 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd, E or Z isomer), 3,3,4,4,4-pentafluorobut-1-ene (HFO-1345fz), and 2,4,4,4-tetrafluorobut-1-ene (HFO-1354mfy). 1,1,2-Trifluoroethylene (HFO-1123), 2,3,3,3-Tetrafluoropropylene (HFO-1234yf), 1,3,3,3-Tetrafluoropropylene (HFO-1234ze, E or Z isomer, preferably E isomer), 1-Chloro-2,3,3,3-Tetrafluoropropylene (HCFO-1224yd, E or Z isomer, preferably Z isomer), Difluoromethane (HFC-32), 1, 1,1,2-Tetrafluoroethane (HFC-134a), 1,1,2,2-Tetrafluoroethane (HFC-134), 1,1-Difluoroethane (HFC-152a), Pentafluoroethane (HFC-125), 1,1,1,3,3-Pentafluoropropane (HFC-245fa), 1,1,1,2,3-Pentafluoropropane (HFC-245eb), 1,1,1,2,3,3-Hexafluoropropane (HFC-236ea), 1,1,1,3,3-pentafluorobutane (HFC-365mfc), fluoroethane (HFC-161), 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), 1,1,1-trifluoropropane (HFC-263fb), 1,2-dichloroethylene (HCO-1130, E or Z isomer, preferably E isomer), and combinations thereof.

[0056] Preferred compounds include, in particular, HCFO-1233zd (preferably in the E form), HFO-1336mzz (preferably in the Z form) and HCFO-1224yd (preferably in the Z form).

[0057] Perhalogenated compounds consist only of carbon atoms and halogen atoms. Examples include perfluorinated compounds such as dodecylfluoropentane, tetradecylfluorohexane, hexadecylfluoroheptane, and combinations thereof.

[0058] Among fluoroketones, examples include fluorinated monoketones, perfluorinated monoketones such as 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone, and combinations thereof.

[0059] Among fluoroethers, examples of hydrofluoroethers may be mentioned, such as methoxynonfluorobutane (HFE7100), ethoxynonfluorobutane (HFE-7200), 1-methoxyheptafluoropropane (HFE-7000), perfluoropolyethers, and combinations thereof.

[0060] The refrigerant may contain multiple compounds, such as two, three, four, or five as described above.

[0061] For example, a refrigerant may consist of (or be substantially composed of) the following:

[0062] -A mixture of HFO-1234yf and HFC-134a;

[0063] A mixture of -HFO-1336mzz(Z) and HCO-1130(E);

[0064] A mixture of HFO-1234ze(E) and HFC-227ea;

[0065] A mixture of HFO-1234yf, HFC-134a and HFC-152a;

[0066] A mixture of HFC-32, HFC-152a and HFO-1234ze(E);

[0067] A mixture of CO2, HFC-134a and HFO-1234ze(E);

[0068] -A mixture of HFC-32, HFO-1234ze(E) and butane;

[0069] A mixture of HFC-32, HFC-125 and HFO-1234ze(E);

[0070] A mixture of HFC-32, HFC-125, HFO-1234yf, HFC-134a and HFO-1234ze(E);

[0071] A mixture of HFC-32, HFC-125, HFO-1234yf and HFC-134a;

[0072] -A mixture of HFC-134a and HFO-1234ze(E);

[0073] A mixture of HFC-32, HFC-125 and HFO-1234yf;

[0074] -A mixture of HFC-32 and HFO-1234yf;

[0075] A mixture of CO2, HFC-32 and HFO-1234yf;

[0076] A mixture of HFC-32, HFC-134a and HFO-1234ze(E);

[0077] -A mixture of HFC-32, HFO-1234yf and HFC-152a;

[0078] -A mixture of HFC-32, HFO-1234yf and HFO-1234ze(E);

[0079] A mixture of HFC-32, HFC-125, HFC-134a and HFO-1234ze(E);

[0080] A mixture of HFC-32, HFC-125, HFC-134a and HFO-1234ze(E);

[0081] A mixture of CO2, HFC-32, HFC-125, HFO-1234yf and HFC-134a;

[0082] A mixture of HFC-32, HFC-125, HFO-1234ze(E) and HFC-227ea; and

[0083] -A mixture of HFC-32, propane and HFO-1234yf.

[0084] Therefore, the refrigerant can be a pure substance or a mixture. When it is a mixture, it is preferably an azeotropic or near-azeotropic mixture.

[0085] The preferred azeotropic composition is a refrigerant:

[0086] -R-513A (56% HFO-1234yf and 44% HFC-134a);

[0087] -R-513B (58.5% HFO-1234yf and 41.5% HFC-134a);

[0088] -R-514A (74.7% HFO-1336mzz(Z) and 25.3% HCO-1130(E));

[0089] -R-515A (88% HFO-1234ze(E) and 12% HFC-227ea);

[0090] -R-516A (77.5% HFO-1234yf, 8.5% HFC-134a and 14% HFC-152a).

[0091] Alternatively, in some embodiments, non-azeotropic compositions and, in particular, refrigerants such as:

[0092] -R-444A (12% HFC-32, 5% HFC-152a and 83% HFO-1234ze(E));

[0093] -R-444B (41.5% HFC-32, 10% HFC-152a and 48.5% HFO-1234ze(E));

[0094] -R-445A (6% CO2, 9% HFC-134a and 85% HFO-1234ze(E));

[0095] -R-446A (68% HFC-32, 29% HFO-1234ze(E) and 3% butane);

[0096] -R-447A (68% HFC-32, 3.5% HFC-125 and 28.5% HFO-1234ze(E));

[0097] -R-447B (68% HFC-32, 8% HFC-125 and 24% HFO-1234ze(E));

[0098] -R-448A (26% HFC-32, 26% HFC-125, 20% HFO-1234yf, 21% HFC-134a and 7% HFO-1234ze(E));

[0099] -R-449A (24.3% HFC-32, 24.7% HFC-125, 25.3% HFO-1234yf and 25.7% HFC-134a);

[0100] -R-449B (25.2% HFC-32, 24.3% HFC-125, 23.2% HFO-1234yf and 27.3% HFC-134a);

[0101] -R-449C (20% HFC-32, 20% HFC-125, 31% HFO-1234yf and 29% HFC-134a);

[0102] -R-450A (42% HFC-134a and 58% HFO-1234ze(E));

[0103] -R-451A (89.8% HFO-1234yf and 10.2% HFC-134a);

[0104] -R-451B (88.8% HFO-1234yf and 11.2% HFC-134a);

[0105] -R-452A (11% HFC-32, 59% HFC-125 and 30% HFO-1234yf);

[0106] -R-452B (67% HFC-32, 7% HFC-125 and 26% HFO-1234yf);

[0107] -R-452C (12.5% ​​HFC-32, 61% HFC-125 and 26.5% HFO-1234yf);

[0108] -R-454A (35% HFC-32 and 65% HFO-1234yf);

[0109] -R-454B (68.9% HFC-32 and 31.1% HFO-1234yf);

[0110] -R-454C (21.5% HFC-32 and 78.5% HFO-1234yf);

[0111] -R-455A (3% CO2, 21.5% HFC-32 and 75.5% HFO-1234yf);

[0112] -R-456A (6% HFC-32, 45% HFC-134a and 49% HFO-1234ze(E));

[0113] -R-457A (18% HFC-32, 70% HFO-1234yf and 12% HFC-152a);

[0114] -R-459A (68% HFC-32, 26% HFO-1234yf and 6% HFO-1234ze(E));

[0115] -R-459B (21% HFC-32, 69% HFO-1234yf and 10% HFO-1234ze(E));

[0116] -R-460A (12% HFC-32, 52% HFC-125, 14% HFC-134a and 22% HFO-1234ze(E));

[0117] -R-460B (28% HFC-32, 25% HFC-125, 20% HFC-134a and 27% HFO-1234ze(E));

[0118] -R-460C (2.5% HFC-32, 2.5% HFC-125, 46% HFC-134a and 49% HFO-1234ze(E));

[0119] -R-460A (12% HFC-32, 52% HFC-125, 14% HFC-134a and 22% HFO-1234ze(E));

[0120] -R-463A (6% CO2, 36% HFC-32, 30% HFC-125, 14% HFO-1234yf and 14% HFC-134a);

[0121] -R-464A (27% HFC-32, 27% HFC-125, 40% HFO-1234ze(E) and 6% HFC-227ea); and

[0122] -R-465A (21% HFC-32, 7.9% propane and 71.1% HFO-1234yf).

[0123] All percentages shown are by weight.

[0124] In some preferred embodiments, the refrigerant comprises HCFO-1233zd in the form of E or Z, more preferably in the form of E.

[0125] Preferably, the heat transfer composition according to the invention contains essentially only a single compound as a refrigerant. In this case, the refrigerant is preferably in the form of E or Z, and more preferably in the form of E, HFO-1233zd.

[0126] Impurities may be present in up to, for example, 1% by weight.

[0127] The refrigerant may specifically include, by weight:

[0128] - At least 99.5%, preferably at least 99.7%, more preferably at least 99.8% of HCFO-1233zd(E);

[0129] - HFC-245fa at a concentration of less than or equal to 500 ppm, preferably 1 to 500 ppm, more preferably 2 to 300 ppm;

[0130] - HFO-1234ze (E or Z) at a content of less than or equal to 100 ppm, preferably 1 to 100 ppm, more preferably 2 to 50 ppm;

[0131] -HCFO-1233zd(Z) at a content of less than or equal to 100 ppm, preferably 1 to 100 ppm, more preferably 2 to 50 ppm.

[0132] Other preferred compositions are:

[0133] - A mixture, preferably a quasi-azeotropic or azeotropic composition, consisting of (or substantially) HCFO-1233zd(E) and HFC-245eb;

[0134] - A mixture consisting of (or substantially consisting of) HFO-1366mzz(Z) and HCO-1130(E), preferably a quasi-azeotropic or azeotropic composition, and more preferably refrigerant R-514A.

[0135] The refrigerant according to the invention may in particular have a liquid viscosity of 0.1 cP to 2 cP at 20°C, preferably 0.2 cP to 0.9 cP at 20°C. The viscosity can be measured according to the method shown in Example 2 below.

[0136] The refrigerant according to the invention can particularly have a liquid saturation temperature of 0°C to 50°C, preferably 10°C to 30°C, and especially 15°C to 25°C at 1 bar.

[0137] The refrigerant according to the invention may particularly have a density of 1 to 1.7, preferably 1 to 1.5, and more preferably 1 to 1.4 at 20°C.

[0138] For the purposes of this invention, the term "dielectric fluid" is understood to mean a fluid that is non-conductive (or has very weak conductivity) but allows the application of electrostatic forces, generally oil.

[0139] The term "oil" refers to a fatty substance that is liquid at ambient temperature and immiscible with water. Oil is a fatty liquid of plant, mineral, or synthetic origin. It may be selected from oils belonging to categories I through V as defined in the API classification (or their equivalents according to the ATIEL classification).

[0140] Insulating (dielectric) oil has the properties of a heat exchange fluid, and therefore participates in heat transfer just like a refrigerant.

[0141] The oil included in the heat transfer composition may be particularly selected from mineral dielectric oils, synthetic dielectric oils (which may optionally be bio-based) and plant dielectric oils, and combinations thereof.

[0142] Preferably, the dielectric fluid comprises at least one mineral dielectric oil. Non-limiting examples of such mineral dielectric oils include paraffinic oils and naphthenic oils, such as dielectric oils from the Nytro family (particularly Nytro Taurus, NytroLibra, Nytro 4000X, and Nytro 10XN) sold by Nynas and Dalia sold by Shell.

[0143] Mineral dielectric oils may preferably be paraffin oils (i.e., saturated linear or branched hydrocarbons), such as Nytro Taurus oil sold by Nynas and Dalia oil sold by Shell, or cycloalkane oils (i.e., cyclic alkanes), such as Nytro Libra and Nytro 10XN oils sold by Nynas, aromatic compounds (i.e., unsaturated cyclic hydrocarbons containing one or more rings characterized by alternating double and single bonds) and non-hydrocarbon compounds.

[0144] Preferably, the dielectric fluid is optionally a bio-based synthetic dielectric oil. Preferably, it may be an aromatic hydrocarbon, an aliphatic hydrocarbon, a silicone oil, an ester, and a polyester, particularly a polyol ester, and a mixture of two or more of these in any proportion.

[0145] In aromatic hydrocarbons, reference may be made in a non-limiting manner to alkylbenzenes, alkyl diphenyl ethanes (e.g., phenylxylenyl ethane (PXE), phenylethyl phenyl ethane (PEPE), monoisopropyl biphenyl (MIPB), 1,1-diphenyl ethane (1,1-DPE)), alkyl naphthalenes (e.g., diisopropyl naphthalene (DIPN)), methyl polyaryl methanes (e.g., benzyltoluene (BT) and dibenzyltoluene (DBT), and mixtures thereof). In said aromatic hydrocarbons, it should be understood that at least one ring is aromatic, and one or more other rings optionally present may be partially or completely unsaturated. Particular reference may be made to Arkema under the name... Dielectric fluids sold by Soltex Inc., and SAS 60E from JX Nippon Chemical Texas Inc.

[0146] In aliphatic hydrocarbons, references may be made in a non-limiting manner to alkanes, poly(α-)olefins (PAOs) such as polyisobutylene (PIB), or vinylidene olefins, such as those sold by, for example, Soltex Inc.

[0147] Alkanes may particularly contain at least 8 carbon atoms, for example 8 to 22 carbon atoms, preferably 15 to 22 carbon atoms.

[0148] PAO can be selected from Class IV and is obtained, for example, from a monomer containing 4 to 32 carbon atoms, such as octene or decene. The weight-average molecular weight of PAO can vary considerably. Preferably, the weight-average molecular weight of PAO is less than 600 Da. The weight-average molecular weight range of PAO can also be 100 to 600 Da, 150 to 600 Da, or even 200 to 600 Da. For example, it exhibits a range of 1.5 to 8 mm when measured at 100°C. 2 The kinematic viscosity of PAO (measured according to standard ASTM D445 at 100°C) is 1 / s by Ineos under the trade name. 162. 164. 166 and 168 Commercial Sales.

[0149] In the context of silicone oils, linear silicone oils of the polydimethylsiloxane type may be mentioned in a non-limiting manner, such as those described by Wacker under the name […]. Those sold by AK.

[0150] In the context of synthetic esters, phthalic acid-type esters may be mentioned in a non-limiting manner, such as dioctyl phthalate (DOP) or diisononyl phthalate (DINP) (e.g., sold by BASF).

[0151] It may also be mentioned in a non-limiting manner as a mixture of polyols and organic acids, particularly those selected from saturated or unsaturated C4 to C5 groups. 22 Esters formed by the reaction of organic acids with each other. Non-limiting examples of such organic acids include undecanoic acid, heptanoic acid, octanoic acid, palmitic acid, and mixtures thereof. Non-limiting examples of polyols that can be used to synthesize the above-mentioned esters include pentaerythritol used to synthesize oils Mivolt DF7, Midel 7131, and Mivolt DFK from M&I Materials.

[0152] Esters can be, for example, of formula R a -C(O)-O-([C(R)2] n -O) s -C(O)-R b The diester, wherein each R independently represents a hydrogen atom or a linear or branched C1-C5 alkyl group, particularly methyl, ethyl, or propyl, especially methyl; s is 1, 2, 3, 4, 5, or 6; n is 1, 2, or 3; it should be understood that when s is not 1, the value of n can be the same or different; and R a and R b—Whether identical or different—each independently represents a saturated or unsaturated and linear or branched hydrocarbon group having a linear sequence of 6 to 18 carbon atoms. Preferably, when s and n are the same and equal to 2, at least one of the R groups represents a linear or branched C1-C5 alkyl group; and when s is 1 and n is 3, at least one of the R groups bonded to the β-position carbon of the ester functional oxygen atom represents a hydrogen atom.

[0153] Synthetic esters produced by the reaction between polyols and organic acids are, for example, Midel7131 from M&I Materials or esters from the Nycodiel series from Nyco.

[0154] In natural esters and vegetable oils, non-limiting examples may include products derived from oily seeds or other natural sources. A non-limiting example may be mentioned is FR 3 sold by Cargill. TM or Envirotemp TM Alternatively, there is Midel EN 1215, which is sold by M&I Materials.

[0155] Polyalkylene glycols (PAGs) can also be used, particularly those obtained by polymerization or copolymerization of epoxides containing 2 to 8 carbon atoms, especially 2 to 4 carbon atoms.

[0156] The heat transfer composition according to the invention may contain one or more oils, such as two, three, four or five oils.

[0157] The preferred dielectric fluid is a polyol ester made from pentaerythritol.

[0158] Another preferred dielectric fluid is a poly(α-)olefin (PAO), which mainly comprises (that is, up to more than 50% by weight) isoparaffins containing 4 to 32 carbon atoms. This fluid belongs to Group IV of the API classification.

[0159] Preferably, the heat transfer composition according to the invention contains only a single dielectric fluid.

[0160] The dielectric fluid may in particular have a viscosity of 1 to 60 cP at 20°C according to standard ISO 3104.

[0161] When measured by boiling point determination, the dielectric fluid may have a boiling point greater than 30°C.

[0162] The dielectric fluid may be present in the composition in an amount of 60% to less than 100% by weight, preferably 85% to 99.5% by weight, relative to the total weight of the heat transfer composition.

[0163] For example, the content relative to the total weight of the heat transfer composition may be 60% to 65% by weight; or 65% to 70% by weight; or 70% to 75% by weight; or 75% to 80% by weight; or 80% to 85% by weight; or 85% to 86% by weight; or 86% to 87% by weight; or 87% to 88% by weight; or 88% to 89% by weight; or 89% to 90% by weight; or 90% to 91% by weight; or 91% to 92% by weight; or 92% to 93% by weight; or 93% to 94% by weight; or 94% to 95% by weight; or 95% to 96% by weight; or 96% to 97% by weight; or 97% to 98% by weight; or 98% to 99% by weight; or 99% to less than 100% by weight.

[0164] The refrigerant may be present in the composition in an amount greater than 0% to 40% by weight, preferably 0.5% to 15% by weight, relative to the total weight of the heat transfer composition.

[0165] For example, relative to the total weight of the heat transfer composition, the content may be greater than 0 wt% to 1 wt%, or 1 wt% to 2 wt%; or 2 wt% to 3 wt%; or 3 wt% to 4 wt%; or 4 wt% to 5 wt%; or 5 wt% to 6 wt%; or 6 wt% to 7 wt%; or 7 wt% to 8 wt%; or 8 wt% to 9 wt%; or 9 wt% to 10 wt%; or 10 wt% to 11 wt%; or 11 wt% to 12 wt%; or 12 wt% to 13 wt%; or 13 wt% to 14 wt%; or 14 wt% to 15 wt%; or 15 wt% to 20 wt%; or 20 wt% to 25 wt%; or 25 wt% to 30 wt%; or 30 wt% to 35 wt%; or 35 wt% to 40 wt%.

[0166] In some embodiments, the heat transfer composition according to the invention comprises a polyol ester prepared from pentaerythritol and at least one fluorinated or chlorofluorocarbon, wherein the fluorinated or chlorofluorocarbon is, for example in a non-limiting manner, hydrofluoropropane, hydrofluoropropylene, hydrochlorofluoropropane, hydrochlorofluoropropylene, and mixtures thereof in any proportion.

[0167] In other embodiments, the heat transfer composition according to the invention comprises a poly(α-)olefin (PAO) and at least one fluorinated or chlorofluorocarbon, said fluorinated or chlorofluorocarbon being, for example in a non-limiting manner, hydrofluoropropane, hydrofluoropropylene, hydrochlorofluoropropane, hydrochlorofluoropropylene, and mixtures thereof in any proportion.

[0168] Preferably, the heat transfer composition according to the invention comprises HCFO-1233zd (preferably in the E form) and a polyol ester made from pentaerythritol. Even more preferably, the heat transfer composition according to the invention consists essentially of, or even entirely of, HCFO-1233zd (preferably in the E form) and a polyol ester made from pentaerythritol.

[0169] Preferably, the heat transfer composition according to the invention comprises HCFO-1233zd (preferably in the E form) and poly(α-)olefin (PAO). Even more preferably, the heat transfer composition according to the invention consists essentially of, or even entirely of, HCFO-1233zd (preferably in the E form) and poly(α-)olefin (PAO). It may also consist essentially of, or entirely of, HFC-245eb, PAO, and HCFO-1233zd in the Z form. It may also consist essentially of, or entirely of, PAO, and HFO-1336mzz in the Z form. It may also consist essentially of, or entirely of, PAO, HFO-1336mzz in the Z form, and HCO-1130 in the E form.

[0170] Compositions that can be used in the context of this invention may further comprise one or more additives and / or fillers, selected in a non-limiting manner from antioxidants, passivators, pour point depressants, decomposition inhibitors, flavorings and tastes, colorants, preservatives, and mixtures thereof. The presence of decomposition inhibitors is particularly preferred.

[0171] Among the antioxidants that may be advantageously used in the composition, non-limiting examples include phenolic antioxidants such as butylated hydroxytoluene, butylated hydroxyanisole, tocopherol, and acetates (esters) of these phenolic antioxidants; amine antioxidants such as phenyl-α-naphthylamine; diamine antioxidants such as N,N'-bis(2-naphthyl)-p-phenylenediamine; ascorbic acid and its salts, esters of ascorbic acid, alone or in mixtures of two or more thereof, or in mixtures with other components such as green tea extract or coffee extract.

[0172] A particularly suitable antioxidant is available from Brenntag under the brand name. Products acquired through commercial purchase.

[0173] The passivating agents that can be used in the context of this invention are advantageously selected from triazole derivatives, benzimidazole, imidazole, thiazole, and benzothiazole. Non-limiting examples that may be mentioned include dioctylaminomethyl-2,3-benzotriazole and 2-dodecyl dithioimidazole.

[0174] Among the pour point depressants that may exist, non-limiting examples include fatty acid esters of sucrose and acrylic polymers such as poly(alkyl methacrylate) or poly(alkyl acrylate).

[0175] The preferred acrylic polymer is one with a molecular weight of 50,000 g·mol⁻¹. -1 and 500,000 g.mol -1 Those in between. Examples of these acrylic polymers include polymers that may contain linear alkyl groups comprising 1 to 20 carbon atoms.

[0176] Among them, as non-limiting examples, poly(methyl acrylate), poly(methyl methacrylate), poly(heptyl acrylate), poly(heptyl methacrylate), poly(nonyl acrylate), poly(nonyl methacrylate), poly(undecyl acrylate), poly(undecyl methacrylate), poly(tetrazyl acrylate), poly(tetrazyl methacrylate), poly(pentadecanyl acrylate), poly(pentadecanyl methacrylate), poly(heptadecyl acrylate) and poly(heptadecyl methacrylate) may be mentioned.

[0177] Examples of such pour point depressants are available commercially under the trade name Aclube from Sanyo Chemical Industries Ltd.

[0178] According to the most particularly preferred aspect, the decomposition inhibitor is present as an additive. The decomposition inhibitor may be particularly selected from carbodiimide derivatives, such as diphenylcarbodiimide, xylylcarbodiimide, bis(isopropylphenyl)carbodiimide, bis(butylphenyl)carbodiimide; and selected from phenyl glycidyl ethers or esters, alkyl glycidyl ethers or esters, 3,4-epoxycyclohexylmethyl(3,4-epoxycyclohexane)carboxylic acid esters, anthraquinone family compounds such as β-methylanthraquinone sold under the name "BMAQ", epoxide derivatives such as vinylcyclohexene diepoxide, 3,4-epoxy-6-methylcyclohexylmethyl(3,4-epoxy-6-methylhexane)carboxylic acid esters, phenolic varnish-type epoxy resins, bisphenol A diglycidyl epoxy ethers, such as DGEBA or CEL2021P, which are particularly available from Whyte Chemicals.

[0179] The total amount of additives preferably does not exceed 5% by weight, particularly 4% by weight, more particularly 3% by weight, and most particularly 2% by weight, or even 1% by weight, of the heat transfer composition.

[0180] The compositions according to the invention can be prepared in any manner known to those skilled in the art, for example by simply mixing the various components of the compositions according to the invention.

[0181] In some embodiments, the heat transfer composition contains impurities. When present, they may comprise less than 1%, preferably less than 0.5%, preferably less than 0.1%, preferably less than 0.05%, and most preferably less than 0.01% (by weight) relative to the heat transfer composition.

[0182] The heat transfer composition according to the invention preferably has a volume resistivity greater than or equal to 10 at 25°C. 6 Ω.cm, and preferably greater than or equal to 10 7 Ω.cm or 10 8 Ω·cm. The resistivity of a material represents its ability to resist the flow of electric current. In other words, volume resistivity is an indicator of the dielectric properties of a composition. Volume resistivity is measured according to standard IEC 60247.

[0183] For example, this volume resistivity can be as high as 10. 6 Up to 5×10 6 Ω.cm; or 5×10 6 Up to 10 7 Ω.cm; or 10 7 Up to 5×10 7 Ω.cm; or from 5×10 7 Up to 10 8 Ω.cm; or from 10 8 Up to 5×10 8 Ω.cm; or from 5×10 8 Up to 10 9 Ω.cm; or greater than 10 9 Ω.cm.

[0184] Furthermore, the heat transfer composition according to the invention preferably has a breakdown voltage of greater than or equal to 20 kV, more preferably greater than or equal to 20 kV, more preferably greater than or equal to 30 kV, more preferably greater than or equal to 50 kV, and more preferably greater than or equal to 100 kV at 20°C. The term "breakdown voltage" is understood to mean the minimum voltage required to make a portion of an insulator conductive. Therefore, this parameter is also an indicator of the dielectric properties of the composition. The breakdown voltage is measured according to standard IEC 60156.

[0185] For example, the breakdown voltage of the composition according to the invention at 20°C can be 25 to 30 kV; or 30 to 40 kV; or 40 to 50 kV; or 50 to 60 kV; or 60 to 70 kV; or 70 to 80 kV; or 80 to 90 kV; or 90 to 100 kV; or 100 to 110 kV; or 110 to 120 kV; or 120 to 130 kV; or 130 to 140 kV; or 140 to 150 kV.

[0186] The heat transfer composition according to the invention may also have a liquid saturation temperature of 20 to 80°C, preferably 30 to 70°C, at a pressure of 1 bar. For example, this temperature may be between 20°C and 25°C; or 25°C and 30°C; or 30°C and 35°C; or 35°C and 40°C; or 40°C and 45°C; or 45°C and 50°C; or 50°C and 55°C; or 55°C and 60°C; or 60°C and 65°C; or 65°C and 70°C; or 70°C and 75°C; or 75°C and 80°C.

[0187] According to standard ISO 3104, the heat transfer composition according to the invention can have a viscosity of 0.1 to 20 cP, particularly at 20°C.

[0188] The heat transfer composition according to the invention is preferably only slightly flammable (that is, having a high flash point, for example greater than 150°C, or greater than 200°C, or greater than 250°C, or greater than 300°C according to standards ISO 3679 and ISO 3680), or more preferably non-flammable.

[0189] Uses of heat transfer compositions

[0190] refer to Figure 1 The battery 402 can power at least one motor 404, particularly a vehicle motor. The vehicle is preferably an automobile, but may also be construction machinery, scooters, motorcycles, trucks, ships, aircraft, etc.

[0191] A battery may include a group of energy storage units (or batteries), which may be grouped together in a single module or multiple modules. Each module may contain multiple batteries arranged in a sealed housing. Each module housing may be configured to hold the batteries in a fixed manner.

[0192] A battery may comprise the same or different modules. These modules may be assembled together mechanically and / or electrically to form a battery. The modules may be electrically connected in series or parallel.

[0193] Each housing may include, for example, an upper portion and a lower portion joined together by welding, adhesive bonding or threaded connection.

[0194] For example, the cell unit may be cylindrical. Each module may include 2 to 200 cell units, preferably 4 to 100 cell units, more preferably 6 to 50 cell units. For example, in each module, the cell units may be arranged in N rows, with M cell units in each row. N may be, for example, 1 to 10, or for example, 2. M may be, for example, 1 to 60, and for example, a multiple of 3 (i.e., 3, 6, 12, 18, 30, etc.). In some embodiments, the cell units may be ordered according to the three-dimensional arrangement in each module, wherein N x M cell units are stacked in P layers. The number of layers P may then have a value of, for example, 2 to 5. Alternatively, a single layer may exist.

[0195] For example, the cell unit can be a rechargeable nickel-cadmium (NiCd), nickel metal hydride (Ni-MH), or lithium-ion (Li-ion) cell unit.

[0196] Each casing can be made, for example, of plastics, particularly polystyrene, polyvinyl chloride, polycarbonate, polyethylene, polypropylene, acrylic polymers, and especially polymethyl methacrylate, phenolic resins, etc. Alternatively, it can be made of metallic materials such as aluminum.

[0197] The heat transfer composition is used to regulate battery temperature. This regulation is achieved by placing the heat transfer composition in direct contact with the battery's energy storage cell, the heat transfer composition being entirely in a liquid state. In other words, the energy storage cell is immersed in the liquid heat transfer composition, and the heat transfer composition undergoes substantially no change in state under normal battery operating conditions.

[0198] Therefore, the heat transfer composition is used for single-phase cooling known as SPLC (“single-phase liquid cooling”) – it should be understood that in some embodiments, it may also be used for single-phase heating or alternatively.

[0199] The term "immersion" should be understood to mean that the cell unit is in contact with the heat transfer composition. More specifically, the outer surfaces of the cell unit are in contact with the heat transfer composition. Preferably, they are in contact with the heat transfer composition, which is in a substantially liquid form.

[0200] Therefore, the cells can be arranged in a heat transfer composition bath. The heat transfer composition can occupy the entire internal space of the module between the cell and the housing wall, or preferably provide a gaseous top space. Preferably, the entire surface of the cell in the housing is in contact with the composition in liquid form.

[0201] Alternatively, the surface of the cell may be covered with a liquid film obtained by appropriate means (spraying, projecting, spraying, etc.) and / or by special treatment of the cell surface.

[0202] For example, the heat transfer composition can be sprayed onto the cell unit using unidirectional or multidirectional nozzles. These nozzles can be arranged, for example, between the cell units to project the heat transfer composition onto the sides of the cell units. Alternatively, they can be placed above the cell units to project the heat transfer composition onto the upper surface of the cell units. The composition can be projected as a jet, dripped, or misted. The composition can be collected in a tank and recirculated by a pump. A heat exchanger and / or heating device (e.g., resistance heating means (devices)) can be arranged in the tank, or upstream or downstream of the pump, to supply heat to or remove heat from the composition. In this variant, the liquid composition can only come into contact with the surface of the cell unit when it is necessary to regulate the temperature of the cell. At other times, and particularly when the cell is not in operation, the surface of the cell unit may not be in contact with the heat transfer composition.

[0203] Optionally, the surface of the cell may be coated with a hydrophilic film to allow a liquid layer of the heat transfer composition to be distributed on the surface of the cell. For example, a nanostructured SiO2 film may be used. Alternatively, filamentous or fibrous structures (including one or more rovings, or woven or nonwoven fabrics), or aggregated metal powder, may be arranged on the surface of the cell to allow a liquid layer of the heat transfer composition to be distributed on the surface of the cell via capillary action.

[0204] Immersion allows for the maximum utilization of the thermal properties of the heat transfer composition. In particular, direct contact of the heat transfer composition with the cell unit of the battery is useful in cases of rapid battery charging, which involves rapid heating of the battery. This allows the temperature to be maintained uniformly within its optimal operating range.

[0205] The heat transfer composition is contained in a device adapted to allow heat exchange between the composition and the cell of the battery, and preferably also allows heat exchange between the composition and a secondary source.

[0206] This device, together with the battery itself, constitutes the battery assembly according to the invention.

[0207] The auxiliary source can be ambient air or another heat transfer composition. When it is ambient air, one or more fans can be used to increase heat exchange with it.

[0208] The heat transfer composition can be static or cyclic.

[0209] If it is static, the device includes a housing of individual cells containing batteries, and a heat transfer composition in contact with these individual cells. The heat transfer composition exchanges heat with the surrounding environment or another heat transfer composition via the housing itself. Therefore, the inner and / or outer walls of the housing may include heat dissipation elements, such as fins or another embossed structure, to facilitate heat exchange with the surrounding environment or another heat transfer composition. Alternatively, the heat transfer composition may exchange heat with another heat transfer composition via a heat exchanger located in the housing, or directly via the walls of the housing, or via plates or channels on the walls of the housing.

[0210] When the heat transfer composition circulates, the device includes a main heat transfer circuit, such as... Figure 1 As shown in the image.

[0211] The flow rate of the heat transfer composition in the main circuit can be 0 to 100 l / min, preferably 5 to 50 l / min.

[0212] Each module's housing may be provided with at least one fluid inlet and at least one fluid outlet, so that the heat transfer composition can pass through the housing, and the cell unit is preferably completely immersed in the heat transfer composition.

[0213] To avoid thermal shock, the temperature of the heat transfer composition at the inlet of the housing is preferably greater than or equal to 10°C, for example, between about 20°C and about 30°C.

[0214] The modules can be fluidly connected in series or in parallel with respect to the heat transfer composition.

[0215] Refer again Figure 1 The main heat transfer circuit can be configured to deliver a heat transfer composition originating from at least one heat exchanger 408, 408' to the battery 402, and again from the battery 402 to at least one heat exchanger 408, 408'. A module housing is incorporated into this main circuit. The main circuit may include one or more conduits for supplying the heat transfer composition to the battery and for collecting it; and optionally for conveying it between modules of the battery. Alternatively, the module housing may be in direct contact to allow for the respective fluid inlets and outlets of the assembled modules. In this case, a seal may be provided between the assembled inlets and outlets.

[0216] When multiple fluid inlets and / or multiple fluid outlets are provided in each housing, the dispenser and collector may be attached to or incorporated into the housing. In some embodiments, portions of the dispenser and collector may be formed in the housing itself so that, when the respective housings are assembled, the heat transfer composition can be collected and dispensed from one module to another.

[0217] When in circulation, the delivery of the heat transfer composition in the main circuit can be provided by one or more pumps 406. The main circuit does not include a compressor: in other words, the main circuit is not a vapor compression circuit.

[0218] The heat exchanger 408 is specifically designed as a radiator to ensure heat exchange with ambient air.

[0219] Alternatively, heat exchanger 408' couples the primary loop to the secondary loop, in which an additional heat transfer composition circulates, exchanging heat with another source (e.g., ambient air).

[0220] The additional heat transfer composition may be the same as or different from the heat transfer composition. For example, the additional heat transfer composition may be a refrigerant as described above, which is not mixed with dielectric fluids. For example, the composition may contain HFO-1234yf, and, if suitable, in combination with one or more lubricants and other additives. Alternatively, it may be, for example, a mixture of water and ethylene glycol.

[0221] The secondary circuit can be a refrigeration circuit, including a compressor, expansion valve, evaporator and condenser; or it can be a simple heat exchange circuit without a compressor.

[0222] An expansion valve (e.g., an electronic expansion valve) may be located upstream of the heat exchanger 408' in the secondary circuit.

[0223] A pump can be provided in this secondary circuit to circulate additional heat transfer composition.

[0224] The additional heat transfer composition may optionally undergo a complete or partial change of state as it passes through heat exchanger 408'. Thus, if the heat transfer composition is cooled in heat exchanger 408', the additional heat transfer composition is correspondingly heated and may completely or partially evaporate (e.g., from a completely liquid state to a two-phase liquid-vapor state). Conversely, if the heat transfer composition is heated in heat exchanger 408', the additional heat transfer composition is correspondingly cooled and may completely or partially condense (e.g., from a two-phase liquid-vapor state to a completely liquid state).

[0225] Optionally, the secondary circuit may be reversible (that is, it may cool or heat the heat transfer composition in contact with the battery depending on the operating mode).

[0226] The heat exchanger 408′ that can exchange heat with other heat transfer compositions can be, for example, co-current or preferably counter-current.

[0227] The term "countercurrent heat exchanger" refers to a heat exchanger in which heat is exchanged between a first fluid and a second fluid, with the first fluid at the inlet of the exchanger exchanging heat with the second fluid at the outlet of the exchanger, and the first fluid at the outlet of the exchanger exchanging heat with the second fluid at the inlet of the exchanger.

[0228] For example, a counter-current heat exchanger includes a device in which the flow of a first fluid and the flow of a second fluid are in opposite or nearly opposite directions. A counter-current heat exchanger also includes an exchanger operating in a cross-flow mode with a counter-current tendency.

[0229] Heat exchangers can be specifically U-tube exchangers, exchangers with horizontal or vertical tube bundles, spiral tube exchangers, plate or finned exchangers.

[0230] The additional heat transfer composition itself can exchange heat with the surrounding environment via a separate heat exchanger. It can also optionally be used to heat or cool the air in the vehicle's passenger compartment. Therefore, heat dissipated through the battery can be absorbed by the vehicle's air conditioning circuit.

[0231] For this purpose, the secondary circuit may include various branches with separate heat exchangers, in which additional heat transfer compositions optionally flow, depending on the operating mode. Optionally, alternatively, or additionally, the secondary circuit may include means for changing the flow direction of the additional heat transfer compositions, such as including one or more three-way or four-way valves.

[0232] The main loop in the circulation system may include a tank for storing excess heat transfer composition in liquid form.

[0233] The secondary circuit may include a vessel for storing excess heat transfer composition in liquid form.

[0234] In the main loop of the circulation system, a protective device can be provided, for example, upstream of the pump, to ensure that only liquid is pumped to the battery. This is because, depending on external conditions (e.g., when the vehicle is hot due to weather conditions upon startup), the heat transfer composition can be two-phase upstream of the pump, particularly at the tank outlet. The protective device may include a bypass system, particularly between the tank and the pump, with valves, pressure sensors, and temperature sensors. Filters and dryers can be provided to capture impurities and moisture, respectively.

[0235] A third circuit containing another additional heat transfer composition may be provided, which is thermally connected to the secondary circuit via a heat exchanger. This third circuit may be specifically dedicated to collecting heat dissipated by the vehicle's motor and / or electrical components.

[0236] It can provide two or more main circuits that can operate in parallel and be controlled independently, in order to regulate the temperature of different modules of the battery or to control different batteries when multiple batteries are present.

[0237] The battery management system 410 can be combined with the battery 402 to measure the electrical parameters (especially voltage) and temperature (by means of a temperature sensor) of each module, and to control the modules and the main circuit (and optionally the secondary circuit) and, in particular, their pumps, to ensure that the electrical parameters and temperature under consideration are within the desired range.

[0238] A specific example of a thermal control system, including a primary circuit and a secondary circuit, will now be described in more detail.

[0239] refer to Figure 2 An example of a battery assembly according to the invention (which is particularly suitable for use in vehicles) includes a thermal regulation system 1 comprising a main circuit 2 containing the aforementioned heat transfer composition and a secondary circuit 3 containing an additional heat transfer composition, the two circuits being thermally connected via at least one heat exchanger 4. During circulation, the heat transfer composition in the main circuit 2 is configured to be agitated by a pump 7. The additional heat transfer composition in the secondary circuit 3 is agitated by a pump 8. The secondary circuit 3 includes an expansion valve 9, which ensures the evaporation of the additional heat transfer composition in the heat exchanger 4 to cool the heat transfer composition in the main circuit 2.

[0240] At least one battery module 10 (as described above) is fluidly incorporated into the main circuit 2. A heating element 11 may be combined with or incorporated into the battery module 10.

[0241] In the circulation system, tank 21 may optionally be located in the main loop 2 to receive excess heat transfer composition in liquid form.

[0242] In battery cooling mode, pump 7 draws heat transfer composition from tank 21 and delivers it to battery module 10. The heat transfer composition remains in a liquid state as it passes through battery module 10.

[0243] The heat transfer composition then passes through heat exchanger 4. Another heat transfer composition expands in expansion valve 9 and then evaporates completely or partially in heat exchanger 4. The heat transfer composition transfers heat to another heat transfer composition. The heat transfer composition then returns to tank 21.

[0244] Secondary circuit 3 can be the vehicle's air conditioning circuit (compressor not shown in the figure).

[0245] refer to Figure 3 and 4An example of a battery assembly according to the invention (particularly applicable to vehicles) includes a thermal regulation system 1, which comprises a main circuit 2 as described above and a secondary circuit 3 capable of operating as a reversible heat pump. Therefore, the battery module 10 can be cooled and heated by a heat transfer composition. The secondary circuit has two operating modes: a cooling mode and a heating mode. The cooling mode... Figure 3 As shown in the diagram, the heating mode is... Figure 4 As shown in the image.

[0246] The secondary loop 3 includes an HVAC (heating, ventilation, and air conditioning) module 16, which provides thermal conditioning of the air in the passenger cabin. It includes a condenser 17 and an evaporator 18. The condenser 17 is used to heat the air in the passenger cabin, while the evaporator 18 is used to cool the air in the passenger cabin.

[0247] The secondary loop 3 further includes a control valve 19, a shut-off valve 24, a tank 37, and an external heat exchanger 20. An expansion valve 9 is located downstream of the external heat exchanger 20, and a calibration orifice 25 with a shut-off function is located upstream of the evaporator 18. The expansion valve 9, shut-off valve 24, and calibration orifice 25 may be electrically controlled. The control valve 19 may be a reversible valve and / or a four-way valve capable of changing the circulation direction of additional heat transfer compositions.

[0248] In cooling mode, control valve 19 is in the first position, causing external heat exchanger 20 to function as a condenser, while heat exchanger 4 and evaporator 18 function as evaporators. In this mode, shut-off valve 24 and calibration orifice 25 are open. The additional heat transfer composition in tank 37 is in a two-phase state, and pump 8 delivers it to external heat exchanger 20. The additional heat transfer composition condenses in the latter and is then sent to heat exchanger 4 and evaporator 18. In both cases, it evaporates at least partially and returns to tank 37.

[0249] In heating mode, control valve 19 is in the second position, causing external heat exchanger 20 to function as an evaporator, while heat exchanger 4 and condenser 17 function as condensers. In this mode, shut-off valve 24 and calibration orifice 25 are closed. The remaining heat transfer composition in tank 37 is in a two-phase state, and pump 8 delivers it to condenser 17, where it is partially condensed. It is then delivered to heat exchanger 4, where it continues to condense. Finally, it passes through external heat exchanger 20, which functions as an evaporator.

[0250] Optionally, a third circuit 12 may be provided and operate in heating mode. The third circuit 12 allows for the collection of heat dissipated by the vehicle's motor 26 and / or electrical components 22. It may include a pump and a radiator 28. A bypass equipped with a shut-off valve 29 allows bypassing the radiator 28. The third circuit 12 is thermally connected to the secondary circuit 3 via a second heat exchanger 13. The third circuit may, for example, comprise a fluid in the form of a mixture of water and glycol. In heating mode, an additional heat transfer composition at the outlet of the heat exchanger 4 is distributed in the external heat exchanger 20 and the second heat exchanger 13, both of which function as evaporators. Therefore, it absorbs the heat dissipated by the fluid in the third circuit 12.

[0251] The secondary circuit 3 may include two check valves 23 (in parallel with the branch including the external heat exchanger 20) on the branch including the second heat exchanger 13, and an expansion valve 9 upstream of the second heat exchanger 13.

[0252] Temperature control

[0253] This invention relates to the use of the heat transfer composition according to the invention for regulating battery temperature. Preferably, the composition is used for cooling a battery. It can also be used for heating a battery. Heating and cooling can be alternated as needed (external temperature, battery temperature, battery operating mode). Heating the battery is particularly useful when starting a vehicle when the external temperature is cold (e.g., below 10°C, or below 0°C, or below -10°C, or below -20°C).

[0254] Heating can also be achieved, at least partially, and in fact, entirely, by means of auxiliary heating elements such as resistance heaters. These auxiliary heating elements can be integrated into the battery.

[0255] Therefore, the heat transfer composition according to the invention can be used only for uniform cooling of the battery, while other devices, such as resistance heaters, are used to heat the battery.

[0256] Alternatively, a heating element associated with the main circuit can be provided, particularly upstream of the battery. In this case, the heating element is capable of heating the heat transfer composition, which in turn heats the battery.

[0257] The term "battery temperature" generally refers to the temperature of the outer wall of one or more of its electrochemical cell units.

[0258] The temperature of the battery can be measured using a temperature sensor. If multiple temperature sensors are present at the battery, the battery temperature can be considered as the average of the measured temperatures. This invention makes it possible to significantly reduce the difference between temperatures measured at different points on the battery.

[0259] Temperature regulation can be performed while the vehicle's battery is charging. Alternatively, it can be performed while the battery is discharging, particularly when the vehicle's motor is running. This effectively prevents the battery temperature from becoming excessively high due to external temperatures and / or due to the inherent heat generated by the battery during operation.

[0260] In particular, the battery can be charged quickly. Therefore, during the full charging process (from the moment the battery is fully discharged) in a time period of less than or equal to 30 minutes, and preferably less than or equal to 15 minutes, using the composition according to the invention allows the battery temperature to be maintained within an optimal temperature range with a uniform distribution. This is advantageous because during fast charging, the battery tends to heat up rapidly and reach high temperatures, particularly with hot spots, which can degrade the battery's operation, performance, safety, and lifespan.

[0261] In some implementations, battery cooling is continuous over a period of time.

[0262] In some implementations, cooling and optional heating allow the battery temperature to be maintained within an optimal range, particularly when the vehicle is running (motor started) and especially when the vehicle is moving. This is because if the battery temperature is too low, its performance is prone to significant degradation.

[0263] In some implementations, the vehicle battery temperature can therefore be maintained between a minimum temperature t1 and a maximum temperature t2.

[0264] In some embodiments, the minimum temperature t1 is greater than or equal to 10°C and the maximum temperature t2 is less than or equal to 80°C, preferably the minimum temperature t1 is greater than or equal to 15°C and the maximum temperature t2 is less than or equal to 70°C, and more preferably the minimum temperature t1 is greater than or equal to 16°C and the maximum temperature t2 is less than or equal to 50°C. For example, t1 may be equal to 20°C (in fact, even greater than 20°C), and t2 may be equal to 40°C (in fact, even less than 40°C).

[0265] Advantageously, a feedback loop exists to modify the operating parameters of the device (cell) based on the measured battery temperature in order to ensure that the desired temperature is maintained.

[0266] During the period when the vehicle battery temperature is maintained between the minimum temperature t1 and the maximum temperature t2, the external temperature may specifically be -60°C to -50°C; or -50°C to -40°C; or -40°C to -30°C; or -30°C to -20°C; or -20°C to -10°C; or -10°C to 0°C; or 0°C to 10°C; or 10°C to 20°C; or 20°C to 30°C; or 30°C to 40°C; or 40°C to 50°C; or 50°C to 60°C; or 60°C to 70°C.

[0267] The term "external temperature" refers to the ambient temperature outside the vehicle before and during the period when the vehicle battery temperature is maintained between the minimum temperature t1 and the maximum temperature t2.

[0268] The present invention also relates to the use of the above-described heat transfer composition for preventing, delaying, or limiting the consequences of battery runaway after a fault (e.g., a short circuit). Runaway is characterized by an uncontrolled rise in temperature, accompanied by the rapid generation of gases, primarily due to the decomposition of the electrolyte, leading to the formation of CO, CO2, HF, and flammable substances (e.g., H2, CH4, C2H4, C2H6, C2H5F) at typical temperatures of 150 to 200°C. The content of flammable gases in the ejected gases can reach at least 30%.

[0269] Therefore, in the event of a malfunction, the above-described heat transfer composition can be used to maintain the battery temperature at less than 150°C, preferably less than 140°C, more preferably less than 140°C, and even more preferably less than 130°C.

[0270] The aforementioned heat transfer composition can also be used to reduce or suppress the flammability of the injected gas mixture in the event of battery runaway. Specifically, it can be used to ensure that the content of flammable gases in the injected gas mixture remains relatively low. It can be used to ensure that the refrigerant content in the injected gas mixture is greater than or equal to 30 mol%, preferably greater than or equal to 40 mol%, or greater than or equal to 50 mol%, or greater than or equal to 60 mol%, or greater than or equal to 70 mol%; in this embodiment, the refrigerant is selected to be non-flammable, i.e., Class A1 in ASHRAE 34 standard; preferably, the refrigerant comprises or consists of HCFO-1233zdE.

[0271] Example

[0272] Example 1 - Miscibility and Dielectric Properties

[0273] By using HCFO-1233zdE as a refrigerant in a mixture of benzyltoluene and dibenzyltoluene (produced by Arkema under the name...) The composition was prepared by combining the two products (C101 sales). It was first confirmed that the two products were miscible in all proportions.

[0274] Oil is introduced into a 0.2L autoclave by weighing. The autoclave is equipped with a magnetic stirrer and a jacket, in which the heat transfer fluid flows to ensure uniform temperature in the gas and liquid phases.

[0275] The autoclave was then cooled to -10°C, at which point a vacuum was drawn.

[0276] The HCFO-1233zdE contained in the cylinder is transferred as a liquid phase in a closed-loop mode by weighing.

[0277] Calculate the minimum volume of liquid to be added so that the composition of the liquid phase does not change as a function of temperature.

[0278] The final mixture is brought to the desired temperature with stirring to homogenize it. The stirring is then turned off until the mixture reaches equilibrium. Temperature and pressure are recorded at equilibrium.

[0279] Figure 5 The effect of refrigerant content on the liquid saturation temperature of the composition at a saturated vapor pressure of 1 bar is shown. More specifically, it was observed that adding refrigerant (even at a low content) to the composition significantly reduced the liquid saturation temperature of the composition relative to a composition containing 100% oil, thus increasing the battery cooling capacity.

[0280] Under the conditions presented below, by mixing 69.2g of HCFO-1233zd E and 100.5g of [unclear - possibly a product name] from Arkema... The composition was prepared using C101.

[0281] [Table 1]

[0282] T-pressure autoclave (°C) Pressure (bar, absolute) Observation results 20 0.71 Miscible 60 2.5 Miscible

[0283] Under the conditions presented below, by mixing 35 wt% HCFO-1233zdE and 65 wt% from Arkema C101 was used to prepare another composition.

[0284] Breakdown voltage is measured according to standard IEC 60159:1995.

[0285] [Table 2]

[0286]

[0287]

[0288] Example 2 - Viscosity

[0289] Viscosity measurements were performed in a high-pressure reactor with a capacity of 0.2 L, containing a jacket through which a heat-transferring fluid flows. The fluid was introduced into the reactor... C101 oil. The reactor was cooled to -10°C and magnetically stirred. Then HCFO-1233zdE was introduced via differential pressure. The reactor was then brought to the measured temperature.

[0290] The viscosity was then measured using a Sofraser MIVI 9601 vibrating rod viscometer. A camera was used to confirm the miscibility of the oil and refrigerant under the measurement conditions, and the immersion of the viscometer rod was checked before the measurement.

[0291] [Table 3]

[0292] HCFO-1233zdE content 0％ 10％ 0％ 10％ T(℃) 20 20 0 0 Dynamic viscosity (cP) 6.0 3.9 12 6.5

[0293] For comparative purposes, the viscosity of the oil (0% HCFO-1233zdE) was measured at 20°C according to standard ISO 3104. The obtained value was 6.5 cP.

[0294] Example 3 - Flammability

[0295] For those containing 90% by weight A composition of C101 oil and 10% by weight of HCFO-1233zdE, and a composition containing 100% by weight of... Flash point measurements were performed on a comparative composition of C101 oil.

[0296] The mixture is prepared at low temperature and atmospheric pressure. It is homogeneous and liquid at ambient temperature and atmospheric pressure.

[0297] Flash point measurement is performed according to standard ISO 3679 or ISO 3680, “Determination of flash / no flash – Rapid equilibrium closed cup method”. The standardized test is performed with the filling port open to vent to the atmosphere while the port remains free, and then the cup is closed.

[0298] Based on the principle of case-by-case testing, the test is adjusted by blocking the filling port to simulate even more constrained devices during temperature equilibration (2 minutes under standardized conditions). In this case, the test is conducted with the capped port closed.

[0299] The temperature range explored is up to 300°C.

[0300] [Table 4]

[0301] HCFO-1233zd E content 0％ 10％ Flash point 138℃ Not detected

[0302] Example 4 - Heat Transfer Coefficient

[0303] For comparative heat transfer coefficient measurements, a test setup was used consisting of a module comprising 36 prismatic cell units (one actual lithium titanate cell surrounded by 35 dummy cells) within a sealed housing. The cell units and the busbar were immersed in a liquid circulating at rates ranging from 0.5 L / min to 40 L / min. The inlet and outlet temperatures, flow rates, and pressures of the liquid were measured and monitored. The liquid was cooled externally.

[0304] The cell units are cooled on their small surfaces. Liquid channels are arranged in parallel. The module is equipped with 26 temperature sensors, eight of which are distributed on one of the large surfaces of the actual cell units.

[0305] At 0 and 1 W / cm 2 Tests were conducted at different heat flux densities F. F is equal to the total heat power provided divided by the total exchange area.

[0306] The tested liquid is either of viscosity and An oil with a similar viscosity to C101, or a mixture of this oil and HCFO-1233zdE. First, introduce HCFO-1233zdE, avoiding the introduction of any moisture or air contamination. Add the oil by gravity using a graduated cylinder. Check miscibility and homogeneity by taking a sample.

[0307] The device was used in automatic testing mode, with a heat flux density F of 0.25 W / cm². 2 (Adjusted by changing the power supply), and the average fluid temperature is 15°C (the average of the liquid temperature at the casing inlet and the liquid temperature at the casing outlet). For a given heat flux density, the liquid flow rate increases to the maximum pumping speed, depending on the fluid.

[0308] The heat transfer coefficient H corresponds to the heat flux density divided by the difference between the fluid temperature at the inlet of the casing and the average cell temperature.

[0309] [Table 5]

[0310]

[0311] For pure oil, the maximum achievable liquid flow rate is 15 l / min. For compositions containing 10% HCFO-1233zdE, the maximum achievable liquid flow rate is 18 l / min.

[0312] Example 5 - Preventing Loss of Control

[0313] The tests were conducted on a compact assembly of eight energy storage cells housed in a sealed housing filled with either fluid A (pure HCFO-1233zdE) or fluid B (10 wt% HCFO-1233zdE + 90 wt% aliphatic hydrocarbon-based dielectric oil). The housing was equipped with a valve calibrated for pressures greater than the vapor pressure of the fluid at 50°C.

[0314] The test was equipped with thermocouples to monitor the temperature of the cell walls and fluids. After washing to remove acidic products, the injected gas was analyzed by gas chromatography.

[0315] The characteristics of a single-cell battery are as follows:

[0316] Model: Samsung INR 18650 35E.

[0317] - Electrical architecture: 1s8p.

[0318] - Capacity: 3.5Ah.

[0319] -Chemical composition: LiNiCoMnO2.

[0320] - Voltage: Minimum 2.5V, nominal 3.6V, maximum 4.2V.

[0321] At time t=0, a short circuit is created by pinning a device to one of the cells that has been charged to its maximum capacity. The associated cell then undergoes thermal runaway, which is reflected by increases in temperature and pressure and the opening of valves in the casing.

[0322] With fluid A, the valve's calibration pressure was 4 bar absolute. The maximum average temperature was 93°C, and the average temperature after 300 s was 63°C. The HCFO-1233zd content in the injected gas was greater than 60 mol%. The H2 content was 9 mol%. The runaway did not propagate to other cell units that remained intact. Gas analysis showed no degradation of HCFO-1233zd.

[0323] In fluid B, the valve's calibration pressure is 1.5 bar absolute. The maximum average temperature is 128°C, and the average temperature after 300 s is 73°C. The HCFO-1233zd content in the injected gas is greater than 50 mol%. The H2 content is 11 mol%. The runaway did not propagate to other cell units that remained intact. Gas analysis showed no degradation of HCFO-1233zd, nor any reaction with oil.

[0324] The complete temperature profile can be found at Figure 6 middle.

Claims

1. Use of a heat transfer composition for regulating battery temperature, the heat transfer composition comprising greater than 0 wt% to 40 wt% of 1-chloro-3,3,3-trifluoropropene and 60 wt% to less than 100 wt% of a dielectric fluid, the battery comprising an energy storage cell immersed in the heat transfer composition in a liquid state, and the heat transfer composition not undergoing a change of state, wherein the dielectric fluid is an aromatic hydrocarbon selected from alkylbenzenes, alkyldiphenylethanes, alkylnaphthalenes, methylpolyarylmethanes, and combinations thereof.

2. The use as described in claim 1, wherein the heat transfer composition is circulated in a heat transfer loop.

3. The use as described in claim 2, wherein the battery comprises one or more modules, each module comprising a housing in which an energy storage unit battery is disposed, the housing forming part of the heat transfer circuit.

4. The use as described in claim 2 or 3, wherein the heat transfer circuit is thermally coupled to a secondary circuit containing an additional transfer composition.

5. The use as described in claim 4, wherein the secondary circuit is a vehicle air conditioning circuit; and / or a reversible heat pump circuit.

6. The use as described in claim 1, wherein 1-chloro-3,3,3-trifluoropropene is in the E form.

7. The use as described in claim 1 or 2, wherein the use is for cooling a battery.

8. The use as described in claim 1 or 2, wherein the battery is a battery for an electric or hybrid vehicle.

9. The use as described in claim 8, wherein the battery is a battery for an electric or hybrid vehicle.

10. The use as described in claim 8, which is carried out during the charging of the vehicle's battery.

11. The use as described in claim 10, wherein the vehicle's battery is fully charged during a period of less than or equal to 30 minutes from the start of its complete discharge.

12. The use as described in claim 10, implemented during the charging of a vehicle's battery, wherein the vehicle's battery is fully charged within a period of less than or equal to 15 minutes from the start of its complete discharge.

13. A battery assembly comprising one or more modules, each module including a housing, wherein an energy storage cell battery is disposed in the housing in a heat transfer composition immersed in a liquid state, the heat transfer composition comprising greater than 0 wt% to 40 wt% of 1-chloro-3,3,3-trifluoropropene and 60 wt% to less than 100 wt% of a dielectric fluid, and the battery assembly being configured such that the heat transfer composition does not undergo a change of state to regulate the battery temperature, wherein the dielectric fluid is an aromatic hydrocarbon selected from alkylbenzenes, alkyldiphenyl ethane, alkylnaphthalenes, methylpolyarylmethane, and combinations thereof.

14. The battery assembly of claim 13, wherein the battery assembly is a battery assembly for an electric or hybrid vehicle.

15. The battery assembly of claim 13, comprising a heat transfer circuit in which a heat transfer composition circulates, and the housing of the module is incorporated into the heat transfer circuit.

16. The battery assembly of claim 15, wherein the heat transfer circuit includes a pump; and / or wherein the heat transfer circuit includes a heat exchanger to enable heat exchange between the heat transfer composition and the heat transfer composition in ambient air or a secondary circuit.

17. The battery assembly of claim 13, wherein 1-chloro-3,3,3-trifluoropropylene is in the E form.

18. A method for adjusting the battery temperature of a battery assembly as described in any one of claims 13 to 17, comprising heating the energy storage cell battery with the heat transfer composition and / or cooling the energy storage cell battery with the heat transfer composition without any change in the state of the heat transfer composition.

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