Device for cooling and / or heating electric vehicle battery packs

Abstract

The invention relates to a device intended for use in a circuit for cooling and / or heating a battery pack of an electric or hybrid motor vehicle, comprising: an outer shell, and an inner shell, an inlet for a heat transfer fluid and an outlet for a heat transfer fluid, the outer shell consisting of a composition comprising: 20% to 65% by weight, relative to the total weight of the composition, of reinforcing fibers having no thermally conductive properties, the remainder being a matrix consisting essentially of at least one polyamide, the inner shell being positioned facing the battery pack and intended to be in contact with the coolant, the inner shell consisting of a composition comprising: 5% to 65% by weight, relative to the total weight of the composition, of reinforcing fibers, when the reinforcing fibers used are thermally non-conductive, 10% to 20% by weight, relative to the total weight, of at least one thermally conductive component, at least one flame retardant, and the remainder being a matrix consisting essentially of at least one polyamide chosen from semiaromatic polyamides and polyamides consisting of units having an average number of carbon atoms per nitrogen atom ranging from 7 to 10, advantageously from 7.5 to 9.5, the device delimiting a battery pack cooling and / or heating volume.

Description

Technical Field

[0001] The present invention generally relates to the field of electric or hybrid motor vehicles requiring the use of battery packs.

[0002] More precisely, the present invention relates to a cooling and / or heating device for a battery pack of an electric or hybrid motor vehicle. Background Art

[0003] One of the goals pursued in the automotive sector is to develop vehicles that produce increasingly less pollution. Consequently, electric and hybrid vehicles, including battery packs, are intended to gradually replace vehicles with internal combustion engines, such as gas or diesel vehicles. Battery packs have proven to be relatively complex vehicle components. Depending on their positioning in the vehicle, they must be protected from impacts and from an external environment that can have extreme temperatures and variable humidity. Furthermore, any risk of fire must be avoided.

[0004] Furthermore, it is important that its operating temperature does not exceed 55° C. in order that the cells of the battery pack do not malfunction and their lifespan is preserved. Conversely, for example in winter, it may be necessary to increase the battery pack temperature in order to optimize its operation.

[0005] Therefore, electric or hybrid motor vehicles require cooling and / or heating devices for the battery pack. Cooling devices for the battery pack that circulate a heat transfer fluid around the battery pack are known, as are battery packs that include a protective compartment. In particular, today, battery packs are equipped with a metal compartment. In addition, the shape given to the metal structure is produced by a stamping method. However, when the compartment shape is complex, for example due to its layout (placement), the stamping method is not the most effective for achieving this type of specificity. The compartment also has the disadvantage of being relatively bulky and breaking down relatively quickly over time, especially if it is located in a humid environment.

[0006] Therefore, a light and resistant structure is sought that can both protect the battery pack from the external environment and act as a heat exchanger. The elements of this device must therefore:

[0007] It is impermeable to the fluids transported and therefore has barrier properties to these fluids (and in particular to fluorocarbon refrigerant compounds such as R134a, R-1234yf or R-1234ze) as well as to water and oxygen. The term "barrier properties" means that the structure is impermeable to the fluids in the vehicle air conditioning lines and therefore does not allow the fluids to escape from the air conditioning lines into the atmosphere.

[0008] - Chemical resistance to the conveyed fluid, compressor oil, water and oxygen to avoid excessive long-term degradation;

[0009] - not only have sufficient mechanical strength (especially bursting strength) but also allow vibration damping;

[0010] - exhibit satisfactory heat resistance, considering that the fluid being transported may be at high temperature and the ambient temperature may also be high (particularly in automotive air conditioning, where the components involved may be arranged near the engine), and in particular heat resistance (resistance) to ZnCl2.

[0011] Therefore, materials are sought that replace known metal structures, meet the specific list of specifications noted above, and improve the heat transfer that occurs between the battery pack and the heat transfer fluid in the cooling and / or heating devices used to cool and / or heat the battery pack. Summary of the Invention

[0012] These objects are achieved by means of a device intended for use in a cooling and / or heating circuit for a battery pack of an electric or hybrid motor vehicle, comprising:

[0013] - a housing, consisting of (consisting of):

[0014] - 20 to 65% by weight of reinforcing fibers having no thermally conductive properties, relative to the total weight of the composition,

[0015] - the balance being a matrix comprising for the most part at least one polyamide, and

[0016] - an inner shell arranged opposite the battery pack and intended to be in contact with the heat transfer fluid, consisting of a composition comprising:

[0017] - 5 to 65% by weight of reinforcing fibers relative to the total weight of the composition,

[0018] - when the reinforcing fibers used are thermally non-conductive, 10 to 20% by weight, relative to the total weight, of at least one thermally conductive component,

[0019] - at least one flame retardant, and

[0020] - a matrix comprising, for the remainder, a majority of at least one polyamide chosen from semiaromatic polyamides and polyamides composed of units having an average number of carbon atoms per nitrogen atom ranging from 7 to 10, advantageously from 7.5 to 9.5;

[0021] - a heat transfer fluid inlet; and

[0022] - heat transfer fluid outlet,

[0023] The device defines a cooling and / or heating volume for the battery pack.

[0024] The cooling and / or heating device for a battery pack according to the present invention has the advantage of being lighter than a device comprising a metal structure. This weight saving (reduction) contributes to the energy or fuel efficiency required for a vehicle to be described as clean.

[0025] It was found that, depending on its placement in the vehicle, the device may be exposed to aggressive environments, such as high temperatures in summer or low temperatures in winter, contact with zinc chloride, shocks or high humidity. It was observed that the device according to the invention has a satisfactory resistance to these external stresses.

[0026] Furthermore, it is observed that the shape of the battery pack can vary depending on the car manufacturer. In fact, manufacturers seek to accommodate the battery pack in spaces that have not been used or are relatively unusable. It is easier to mold or inject plastic than to mold or inject metal sheets. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A cross-sectional view of a cooling and / or heating device for a battery pack of an electric or hybrid motor vehicle.

[0028] Figure 2 is a cross-sectional view of a portion of a cooling and / or heating device for a battery pack of an electric or hybrid automotive vehicle, Figure 2 Display as Figure 1 Alternative housing configurations to the housing shown in .

[0029] Figure 3 A cooling and / or heating circuit for a battery pack is shown, which is incorporated into a device according to the invention.

[0030] Figure 4 A cooling and / or heating circuit for a battery pack incorporating a device according to the invention comprising two heat transfer loops is shown. DETAILED DESCRIPTION

[0031] Other characteristics, features, subjects and advantages of the invention will appear even more clearly on reading the description and examples that follow.

[0032] It is further specified that the expressions “between… and…” and “from… to…” used in this description must be understood to include the respective stated limit values.

[0033] Device

[0034] The device according to the present invention comprises:

[0035] -shell,

[0036] -Inner shell,

[0037] - a heat transfer fluid inlet; and

[0038] - heat transfer fluid outlet,

[0039] The device defines a cooling and / or heating volume for the battery pack.

[0040] shell

[0041] The shell is composed of a composition comprising:

[0042] - 20 to 65% by weight of reinforcing fibers relative to the total weight of the composition,

[0043] The balance is a matrix comprising for the most part at least one polyamide.

[0044] polyamide

[0045] The term "polyamide" refers equally to homopolyamides or copolyamides.

[0046] The nomenclature used to define polyamides is described in ISO Standard 1874-1:2011 “Plastiques—Material polyamide (PA) pour moulage et extrusion—Partie 1: Designation”, in particular page 3 (Tables 1 and 2), and is known to the skilled person.

[0047] Polyamides are obtainable by polycondensation of lactam units, amino acid units and / or XY units, wherein X is a diamine and Y is a dicarboxylic acid (or diacid).

[0048] Lactams and amino acids have 4 to 12 carbon atoms. Preferably, they are selected from pyrrolidone, 2-piperidone, caprolactam, aminocaproic acid, nonanolactam, caprolactam, undecanoic acid, 10-aminoundecanoic acid, amino-11-undecanoic acid, amino-12-dodecanoic acid, lauryl lactam, enantholactam and capryllactam.

[0049] Advantageously, the lactams and amino acids are C11 and C12.

[0050] The diamines may be linear or branched aliphatic or cycloaliphatic, preferably linear or branched aliphatic, in particular linear. The dicarboxylic acids may be aliphatic, cycloaliphatic or aromatic, and preferably aliphatic or aromatic.

[0051] In the case of polyamides obtained from the polycondensation of XY units, the diamine (X) may be C4-C36, particularly C6-C22, especially C6-C18, and the dicarboxylic acid (Y) may be C4-C36, particularly C6-C22, especially C6-C18.

[0052] Advantageously, the diamine is selected from the group consisting of butanediamine, pentanediamine, 2-methyl-1,5-pentanediamine, 1,6-hexamethylenediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1,10-decanediamine 1,11-undecanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,12-dodecanediamine, 1,13-tridecanediamine, 1,14-tetradecanediamine, hexadecanediamine, octadecanediamine, octadecenediamine, eicosanediamine, docosanediamine, and fatty acid diamines, 1,3-xylylenediamine (MXD) and 1,4-xylylenediamine (PXD), diamines. (3,5-dialkyl-4-aminocyclohexyl)methane, bis(3,5-dialkyl-4-aminocyclohexyl)ethane, bis(3,5-dialkyl-4-aminocyclohexyl)propane, bis(3,5-dialkyl-4-aminocyclohexyl)-butane, bis(3-methyl-4-aminocyclohexyl)methane or 3'-dimethyl-4,4'-diamino-dicyclohexyl-methane, often referred to as "BMACM" or "MACM" (hereinafter referred to as B), p-bis(aminocyclohexyl)methane, often referred to as "PACM" (hereinafter referred to as P), isopropylidenebis(cyclohexylamine), often referred to as "PACP", isophoronediamine (hereinafter referred to as IPD) and 2,6-bis(aminomethyl)norbornane, often referred to as "BAMN", in particular 1,10-decanediamine.

[0053] A non-exhaustive list of these cycloaliphatic diamines is given in the publication “Cycloaliphatic Amines” (Encyclopaedia of Chemical Technology, Kirk-Othmer, 4th edition (1992), pages 386-405).

[0054] Advantageously, the dicarboxylic acid is chosen from succinic acid, pentanediolic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanoic acid, octadecenoic acid, eicosanedioic acid, docosanedioic acid, and dimers of fatty acids containing 36 carbons, terephthalic acid (denoted by T), isophthalic acid (denoted by I), and in particular dodecanedioic acid.

[0055] Advantageously, the diamine is selected from 1,8-octanediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1,10-decanediamine, 1,11-undecanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,12-dodecanediamine, 1,13-tridecanediamine, 1,14-tetradecanediamine, in particular 1,10-decanediamine, and the dicarboxylic acid is selected from sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, terephthalic acid (denoted by T), isophthalic acid (denoted by I), in particular dodecanedioic acid.

[0056] More advantageously, the lactam is lauryl lactam, the amino acid is selected from 10-aminoundecanoic acid, 11-aminoundecanoic acid, 12-amino-dodecanoic acid, the diamine is selected from 2-methyl-1,5-pentanediamine, 1,6-hexamethylenediamine, 1,9-nonanediamine, 2-methyl-1,8-octane-diamine, 1,10-decanediamine and 1,12-dodecanediamine, and the dicarboxylic acid is selected from adipic acid, sebacic acid, dodecanedioic acid, terephthalic acid (denoted as T) and isophthalic acid (denoted as I).

[0057] According to a highly preferred embodiment, the lactam is lauryl lactam, the amino acid is selected from 10-aminoundecanoic acid, 11-aminoundecanoic acid, 12-amino-dodecanoic acid, the diamine is selected from 2-methyl-1,5-pentanediamine, 1,6-hexamethylenediamine, 1,10-decanediamine and 1,12-dodecanediamine, and the dicarboxylic acid is selected from adipic acid, sebacic acid, dodecanedioic acid, terephthalic acid (denoted as T) and isophthalic acid (denoted as I).

[0058] Preferably, the shell comprises a polyamide matrix comprising at least one polyamide chosen from semiaromatic polyamides and polyamides composed of units having an average number of carbon atoms per nitrogen atom ranging from 9 to 18.

[0059] The average number of carbon atoms per nitrogen atom is the average number of carbon atoms per unit (that is, per linkage between two nitrogen atoms). Within polyamides, units are linked to each other via the amide functional group -CO-NH-. Therefore, there are as many nitrogen atoms as there are (-CO-NH-)amide groups. In the case of a PA-XY homopolyamide, the number of carbon atoms per nitrogen atom is the average of units X and Y. Thus, PA612, derived from the polycondensation of hexanediamine and dodecanedioic acid, is a PA with 9 carbon atoms per nitrogen atom; in other words, it is a C9 PA based on the following calculation: (6 + 12) / 2. In the case of copolyamides, the number of carbon atoms per nitrogen atom is calculated according to the same principle. This calculation is performed using the molar ratios of the various amide units. Thus, a co-PA-6.T / 6.6, comprising 60% 6T and 40% 66, is C6,6: 60% x [(6 + 8) / 2] + 40% x [(6 + 6) / 2] = 6.6.

[0060] Advantageously, the polyamide present in the composition of the casing is chosen from PA612, PA1010, PA10T, PA10T / 1010, PA11, PA12, PA11 / 10T, PA12 / 10T, PA 1012, PA 618, PA 12T, PA 1010 / 1012, PA BACT / 6T, PABACT / 10T, PA BACT / 12T PA MPMDT / 6T, PA MPMDT / 10T, PA MPMDT / 12T, PA MXDT / 6T, PAMXDT / 10T, PA MXDT / 12T, PA 11 / BACT / 6T, PA 11 / BACT / 10T, PA 11 / BACT / 12T, PA 11 / MPMDT / 6T, PA 11 / MPMDT / 10T, PA 11 / MPMDT / 12T, PA Preferably, the polyamide constituting the matrix of the shell is selected from PA12, PA11, PA1010, PA1012 and PA11 / 10T.

[0061] The term "majority" is understood within the meaning of the present invention to mean a proportion of polyamide greater than 50% in the matrix of the composition. Preferably, the polyamide(s) represent from 50 to 80% by weight relative to the total weight of the matrix.

[0062] According to a preferred embodiment, the composition of the casing comprises more than 25% by weight of polyamide, relative to the total weight of the composition.

[0063] Reinforcement fiber

[0064] The composition constituting the shell according to the invention comprises from 20 to 65% by weight of reinforcing fibers relative to the total weight of the composition.

[0065] The fibers present in the composition of the shell may be of different sizes. The reinforcing fibers may be short, long or continuous. Mixtures of these various sizes and / or types of fibers may also be used.

[0066] Preferably, the length of "short" fibers is between 200 μm and 400 μm. So-called long fibers preferably have a length of more than 1000 μm. The length of glass fibers is measured according to ISO 22314:2006(E).

[0067] These reinforcing fibers can be selected from:

[0068] mineral fibers having a high melting temperature Tm′ greater than the melting temperature Tm of the polyamide present in the matrix of the composition of the shell according to the invention and greater than the polymerization and / or implementation temperature,

[0069] - polymeric or polymeric fibers having a melting temperature Tm' or a glass transition temperature Tg' greater than the polymerization temperature or greater than the melting temperature Tm of said polyamide present in the matrix of the composition of the shell according to the invention and greater than the implementation temperature,

[0070] - natural fibers;

[0071] - or a mixture of the above fibers;

[0072] Examples of inorganic fibers suitable for the present invention are: carbon fibers, including nanotubes or carbon nanotube (CNT) fibers, carbon nanofibers or graphene; silica fibers, such as glass fibers, in particular type E, R or S2; boron fibers; ceramic fibers, in particular silicon carbide fibers, boron carbide fibers, boron carbonitride fibers, silicon nitride fibers, boron nitride fibers, basalt fibers; fibers or filaments containing metals and / or alloys thereof; metal oxide fibers, in particular aluminum oxide (Al2O3) fibers; metallized fibers, such as metallized glass fibers and metallized carbon fibers; or mixtures of the aforementioned fibers.

[0073] As polymer fibers suitable for the present invention, the following can be cited:

[0074] Fibers based on amorphous thermoplastic polymers and having a glass transition temperature Tg greater than the Tg of the polyamide or polyamide mixture present in the matrix when it is amorphous or greater than the Tm of the polyamide or polyamide mixture present in the matrix when it is semi-crystalline. Advantageously, they are based on semi-crystalline thermoplastic polymers and have a melting point Tm greater than the Tg of the polyamide or polyamide mixture present in the matrix when it is amorphous or greater than the Tm of the polyamide or polyamide mixture present in the matrix when it is semi-crystalline. Thus, there is no risk of melting the organic fibers constituting the reinforcement during the impregnation of the final composite with the thermoplastic matrix.

[0075] - thermosetting polymer fibers, and more particularly chosen from: unsaturated polyesters, epoxies, vinyl esters, phenolic resins, polyurethanes, cyanoacrylates, and polyimides such as bis-maleimide resins, aminoplasts resulting from the reaction of amines such as melamine with aldehydes such as glyoxal or formaldehyde,

[0076] - fibers of thermoplastic polymers, and more particularly chosen from: polyethylene terephthalate (PET), polybutylene terephthalate (PBT);

[0077] -polyamide fibers,

[0078] - Aramid fibers (e.g. ) and aromatic polyamides, such as those having one of the following formulae: PPDT, MPDI, PAA, and PPA, wherein PPD and MPD are p- and m-phenylenediamine, respectively, PAA is polyaramid, and PPA is polyphthalamide;

[0079] Fibers of polyamide block copolymers, such as polyamide / polyether, fibers of polyaryletherketones (PAEK), such as polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetherketoneetherketoneketone (PEKEKK).

[0080] Among the fibers of natural origin and in particular vegetable fibers, the following may be mentioned: fibers based on flax, ricin, wood, kenaf, coconut, hemp, jute, lignin, bamboo, silk, in particular spider silk, sisal and other cellulosic fibers, in particular viscose. These vegetable fibers can be used in pure form, treated or coated to improve adhesion and impregnation of the polymer matrix.

[0081] The reinforcing fibers may constitute a fiber material which may also be a fabric woven or woven from the fibers.

[0082] It can also correspond to a fiber with a supporting strand. These component fibers can be used individually or in a mixture. Thus, organic fibers can be mixed with mineral fibers to impregnate with a polymer matrix and form a pre-impregnated fiber material.

[0083] Organic fiber strands can have a variety of weights. They can also have a variety of geometric shapes. The fibers can be in the form of staple fibers, forming mats or nonwovens that can be in the form of tapes, layers, or sheets, or in the form of continuous fibers, forming unidirectional (UD) or nonwoven 2D fabrics, braids, or strands. The component fibers of the fibrous material can furthermore be in the form of a mixture of these reinforcing fibers having different geometric shapes.

[0084] Preferably, the fiber material consists of continuous carbon, glass or silicon carbide fibers or mixtures thereof, in particular carbon fibers. It is used in the form of a yarn bundle or several yarn bundles.

[0085] Preferred short reinforcing fibers are short fibers selected from the group consisting of carbon fibers, including metallized fibers, glass fibers, including metallized glass fibers such as E, R, S2, aramid fibers (such as ) or aromatic polyamide, polyaryletherketone (PAEK) fibers such as polyetheretherketone (PEEK), polyetherketoneketone (PEKK) fibers, polyetherketoneetherketoneketone (PEKEKK) fibers, or mixtures thereof.

[0086] Preferably, the reinforcing fibers are selected from glass, carbon, ceramic and aramid fibers or mixtures thereof.

[0087] Preferably, the housing of the device according to the invention has thermal insulating properties.According to this preferred embodiment, the reinforcing fibers will preferably be selected from glass fibers, basalt fibers and aramid fibers.

[0088] The content of reinforcing fibers in the composition may vary depending on the size of the fibers used: short, long or continuous.

[0089] Thus, in the case of short reinforcing fibers, the fiber content is preferably between 20 and 60% by weight of reinforcing fibers. In the case of long or continuous reinforcing fibers, the fiber content is preferentially between 40 and 65% by weight of reinforcing fibers.

[0090] flame retardants

[0091] The composition constituting the housing of the device according to the invention may comprise at least one flame retardant.

[0092] Preferably, the fire retardant is selected from halogen-free fire retardants, such as those described in US 2008 / 0,274,355, and in particular, metal salts selected from the following: metal phosphinic acid salts, metal salts of bisphosphinic acid, polymers containing at least one metal salt of phosphinic acid, and polymers containing at least one metal salt of bisphosphinic acid. The fire retardant may also be selected from red phosphorus, antimony oxide, zinc oxide, iron oxide, magnesium oxide, metal borates such as zinc borate, melamine pyrophosphate, melamine cyanurate, and siliconized or fluorinated anti-drip agents. The fire retardant may also be a mixture of the aforementioned flame retardants.

[0093] They may also be halogenated flame retardants such as brominated or polybrominated polystyrene, brominated polycarbonates or brominated phenols.

[0094] The flame retardant may also be selected from metal salts of phosphinic acid of the following formula (I) and metal salts of bisphosphinic acid of the following formula (II):

[0095]

[0096] in

[0097] R1 and R2 independently of one another represent a linear or branched C1-C6 alkyl group or an aryl group;

[0098] R3 represents a linear or branched C1-C10 alkylene group, a C6-C10 arylene group, a C6-C10 alkylarylene group, or a C6-C10 arylalkylene group,

[0099] M is Mg, Ca, Al, Sb, Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, K and / or a protonated amine base

[0100] -m is an integer ranging from 1 to 4;

[0101] -n is an integer ranging from 1 to 4;

[0102] -x is an integer ranging from 1 to 4;

[0103] n and m are chosen so that the salt is neutral, meaning that it carries no charge.

[0104] Preferably, M represents a calcium, magnesium, aluminum or zinc ion.

[0105] Preferably, R1 and R2 independently of one another denote a methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-pentyl and / or phenyl group.

[0106] Preferably, R3 represents a methylene, ethylene, n-propylene, isopropylene, n-butylene, tert-butylene, n-pentylene, n-octylene, n-dodecylene, phenylene, naphthylene, methylphenylene, ethylphenylene, tert-butylphenylene, methylnaphthylene, ethylnaphthylene, tert-butylnaphthylene, phenylmethylene, phenylethylene, phenylpropylene or phenylbutylene group.

[0107] The flame retardant may be the flame retardant sold by Clariant with the trade name Exolit OP 1230, which is the aluminum salt of diethylphosphinic acid (CAS No. 225789-38-8).

[0108] More particularly, the flame retardant content is from 0 to 30% by weight, preferably from 15 to 25% by weight and more particularly from 17 to 22% by weight relative to the total weight of the composition.

[0109] Impact modifiers

[0110] The composition constituting the shell of the device according to the invention may comprise at least one impact modifier. Preferably, the composition constituting the shell of the device according to the invention may comprise from 0 to 20% by weight of at least one impact modifier relative to the total weight of the composition.

[0111] The impact modifier is advantageously composed of a polymer having a flexural modulus measured at 50% RH according to standard ISO 178 below 100 MPa and a Tg measured according to standard 11357-2 of 2013 below 0°C.

[0112] The glass transition temperature Tg of the polyamide is measured using a differential scanning calorimeter (DSC) after the second heating pass in accordance with ISO standard 1 1357-2: 2013. The heating and cooling rates are 20° C. / min.

[0113] Preferably, the impact modifier consists of one or more polyolefins, some or all of which carry functional groups selected from carboxylic acid, carboxylic anhydride and epoxide functional groups. Quite particularly, the polyolefin can be chosen from elastomeric ethylene and propylene copolymers (EPR), elastomeric ethylene-propylene-diene copolymers (EPDM) and ethylene / alkyl (meth)acrylate copolymers.

[0114] The composition may comprise up to 20% by weight, relative to the total weight of the composition, of a semicrystalline polyolefin or polyolefin mixture having a flexural modulus measured at 50% RH according to ISO Standard 178 exceeding 300 MPa, advantageously exceeding 800 MPa.

[0115] The impact modifier may be a functionalized polyolefin (B1).

[0116] According to the invention, functionalized polyolefins (B1) are understood to mean the following polymers.

[0117] The functionalized polyolefin (B1) may be an α-olefin polymer having reactive units (functional groups). Such reactive units are carboxylic acid, anhydride or epoxy functional groups.

[0118] Homopolymers or copolymers of α-olefins or dienes may be given as examples of polyolefins such as, for example, ethylene, propylene, 1-butene, 1-octene, butadiene, and more particularly:

[0119] - homopolymers and copolymers of ethylene, in particular LDPE, HDPE, LLDPE (linear low-density polyethylene), VLDPE (very low-density polyethylene) and metallocene polyethylene;

[0120] - homopolymers or copolymers of propylene;

[0121] Ethylene / α-olefin copolymers, such as ethylene / propylene, EPR (abbreviation for ethylene-propylene-rubber) and ethylene / propylene / diene (EPDM).

[0122] - Styrene / ethylene-butylene / styrene (SEBS), styrene / butadiene / styrene (SBS), styrene / isoprene / styrene (SIS), styrene / ethylene-propylene / styrene (SEPS) block copolymers;

[0123] - copolymers of ethylene with at least one product chosen from the group consisting of salts or esters of unsaturated carboxylic acids, such as alkyl (meth)acrylates (for example methyl acrylate) or vinyl esters of saturated carboxylic acids, such as vinyl acetate (EVA), in which the proportion of comonomer may be up to 40% by weight.

[0124] These polyolefins can be grafted, copolymerized or terpolymerized via reactive units (functional groups) such as carboxylic acid, anhydride or epoxy functional groups.

[0125] More specifically, these polyolefins are grafted or copolymerized or terpolymerized by unsaturated epoxides such as glycidyl (meth)acrylate, or by carboxylic acids or corresponding salts or esters such as (meth)acrylic acid (which may be fully or partially neutralized by metals such as Zn, etc.), or by carboxylic anhydrides such as maleic anhydride.

[0126] Functionalized polyolefins (B1) can be selected from the following (co)polymers grafted with maleic anhydride or glycidyl methacrylate, wherein the grafting rate is, for example, 0.01 to 5% by weight:

[0127] PE, PP, copolymers of ethylene with propylene, butene, hexene or octene, containing, for example, 35 to 80% by weight of ethylene;

[0128] Ethylene / α-olefin copolymers, such as ethylene / propylene, EPR (abbreviation for ethylene-propylene-rubber) and ethylene / propylene / diene (EPDM);

[0129] - Styrene / ethylene-butylene / styrene (SEBS), styrene / butadiene / styrene (SBS), styrene / isoprene / styrene (SIS), styrene / ethylene-propylene / styrene (SEPS) block copolymers;

[0130] - ethylene and vinyl acetate copolymers (EVA) containing up to 40% by weight of vinyl acetate;

[0131] - copolymers of ethylene and alkyl (meth)acrylates containing up to 40% by weight of alkyl (meth)acrylates;

[0132] - copolymers of ethylene and vinyl acetate (EVA) and alkyl (meth)acrylates containing up to 40% by weight of comonomers.

[0133] Functionalized polyolefins are, for example, PE / EPR mixtures, the weight ratio of which can vary widely, for example between 40 / 60 and 90 / 10, which are co-grafted with anhydrides, in particular maleic anhydride, at a grafting rate of, for example, 0.01 to 5% by weight.

[0134] Functionalized polyolefins (B1) can also be chosen from ethylene / propylene copolymers with predominantly maleic anhydride-grafted propylene condensed with monoamine polyamides (or polyamide oligomers) (products described in EP-A-0,342,066).

[0135] The functionalized polyolefin (B1) may also be a copolymer or terpolymer of at least the following units:

[0136] (1) Ethylene;

[0137] (2) alkyl methacrylates or vinyl esters of saturated carboxylic acids; and

[0138] (3) Acid anhydrides such as maleic anhydride or methacrylic anhydride, or epoxy compounds such as glycidyl methacrylate.

[0139] As examples of functionalized polyolefins of the latter type, mention may be made of the following copolymers, in which the proportion of ethylene in the copolymer is preferably at least 60% by weight and in which the proportion of termonomers (functional groups) is, for example, from 0.1 to 12% by weight:

[0140] - ethylene / alkyl (meth)acrylate / (meth)acrylic acid or maleic anhydride or glycidyl methacrylate copolymers;

[0141] - ethylene / vinyl acetate / maleic anhydride or glycidyl methacrylate copolymers;

[0142] - Ethylene / vinyl acetate or alkyl (meth)acrylate / (meth)acrylic acid or maleic anhydride or glycidyl methacrylate copolymers.

[0143] In the foregoing copolymers, (meth)acrylic acid may be salted with Zn or Li. The term "alkyl (meth)acrylate" in (B1) refers to C1 to C8 alkyl methacrylates and acrylates, and may be selected from methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethyl-hexyl acrylate, cyclohexyl acrylate, methyl methacrylate, and ethyl methacrylate.

[0144] Moreover, the aforementioned polyolefin (B1) can also be crosslinked by any suitable method or reagent (diepoxides, diacids, peroxides, etc.); the term functionalized polyolefin also includes a mixture of the aforementioned polyolefin and a difunctional reactant capable of reacting therewith (such as diacids, dianhydrides, diepoxides, etc.), or a mixture of at least two functionalized polyolefins capable of reacting together.

[0145] The copolymers (B1) mentioned above may be statistical or sequential copolymers and have a linear or branched structure.

[0146] The molecular weight, index MFI, density of these polyolefins can also vary widely, as will be known to those skilled in the art. MFI, the abbreviation for melt flow index, is the measure of fluidity when melted. It is measured according to standard ASTM 1238.

[0147] Advantageously, the functionalized polyolefin (B1) is chosen from any polymer comprising α-olefin units and units carrying polar reactive functional groups such as epoxy, carboxylic acid or carboxylic anhydride functional groups. As examples of such polymers, mention may be made of terpolymers of ethylene, alkyl acrylates and maleic anhydride or glycidyl methacrylate, such as the terpolymers of the applicant's or maleic anhydride grafted polyolefins such as those from the applicant and terpolymers of ethylene, alkyl acrylates and (meth)acrylic acid. Mention may also be made of homopolymers or copolymers obtained by grafting polypropylene with carboxylic anhydrides and then condensing them with polyamide or polyamidemonoamine oligomers, as described in application EP 0,342,066.

[0148] More specifically, the functionalized polyolefin (B1) is:

[0149] - terpolymers of ethylene, alkyl acrylate and maleic anhydride;

[0150] - a terpolymer of ethylene, an alkyl acrylate and glycidyl methacrylate;

[0151] - Maleic anhydride grafted polypropylene and polyethylene;

[0152] - maleic anhydride grafted copolymers of ethylene and propylene and possibly diene monomers;

[0153] - Maleic anhydride grafted ethylene and octene copolymers;

[0154] and mixtures thereof.

[0155] The functionalized polyolefin (B1) is present in a concentration of between 0 and 20% by weight, preferably between 1 and 10% by weight, relative to the total weight of the composition.

[0156] Advantageously, the composition according to the invention may comprise at least one non-functionalized polyolefin (B2).

[0157] The non-functionalized polyolefins (B2) are conventionally homopolymers or copolymers of α-olefins or dienes such as, for example, ethylene, propylene, 1-butene, 1-octene, butadiene. By way of example, mention may be made of:

[0158] - homopolymers and copolymers of polyethylene, in particular LDPE, HDPE, LLDPE (linear low-density polyethylene), VLDPE (very low-density polyethylene) and metallocene polyethylene;

[0159] - homopolymers or copolymers of propylene;

[0160] Ethylene / α-olefin copolymers, such as ethylene / propylene, EPR (abbreviation for ethylene-propylene-rubber) and ethylene / propylene / diene (EPDM);

[0161] - Styrene / ethylene-butylene / styrene (SEBS), styrene / butadiene / styrene (SBS), styrene / isoprene / styrene (SIS), styrene / ethylene-propylene / styrene (SEPS) block copolymers;

[0162] - copolymers of ethylene with at least one product chosen from the group consisting of salts or esters of unsaturated carboxylic acids, such as alkyl (meth)acrylates (for example methyl acrylate), or vinyl esters of saturated carboxylic acids, such as vinyl acetate (EVA), in which the proportion of the comonomer may be up to 40% by weight;

[0163] and mixtures thereof.

[0164] The above-mentioned copolymers (B2) may be statistical or sequential copolymers and have a linear or branched structure.

[0165] Advantageously, the non-functionalized polyolefin (B2) is selected from polypropylene and any ethylene homopolymer or ethylene copolymer and a homopolymer or copolymer of a higher α-olefin comonomer such as butene, hexene, octene or 4-methyl-1-pentene. PP (polypropylene), high-density polyethylene, medium-density polyethylene, linear low-density polyethylene, low-density polyethylene and very low-density polyethylene can be cited as examples. These polyethylenes are known to those skilled in the art as products from free radical processes, from Ziegler catalytic processes and more recently from metallocene catalysis. Copolymers of ethylene and vinyl acetate (EVA) are also preferred, for example the copolymers known by the applicant under the trade name Those that are sold.

[0166] When the composition constituting the housing of the device according to the present invention comprises one or more non-functionalized polyolefins, the MFI of (A) and the MFI of (B1) and (B2) can be selected within a wide range, but it is recommended that the viscosities of (B1) and (B2) are close to improve the dispersion of (B1) and (B2).

[0167] The non-functionalized polyolefin is present in a concentration of between 0 and 20% by weight, preferably between 1 and 10% by weight, relative to the total weight of the composition.

[0168] The impact modifier may also be a copolymer formed from polyamide blocks and polyether blocks, wherein the polyamide blocks and the polyether blocks are linked via ester functions. These products are described in document FR 2 273 021 and are marketed by Arkema as Product name sales.

[0169] The copolymer having a polyamide block (hereinafter abbreviated as PA) and a polyether block (hereinafter abbreviated as PE) is produced by the co-condensation of a polyamide block having a reactive terminal and a polyether block having a reactive terminal. For example, the following substances can be reacted:

[0170] - polyether diol and carboxylic acid polyamide,

[0171] - polyetherdiamine and carboxylic acid polyamide;

[0172] -Polyether diols and diamine polyamides.

[0173] Block polyamides with dicarboxylic acid chain ends are derived, for example, from the condensation of polyamide precursors in the presence of a carboxylic acid chain regulator. Block polyamides with diamine chain ends are derived, for example, from the condensation of polyamide precursors in the presence of a diamine chain regulator. Thus, the bonds between the blocks are ester or amide bonds. Polymers with PA blocks and PE blocks may include a single PA block and a single PE block.

[0174] They may also include several structurally identical PA blocks and randomly distributed identical PE blocks of the monomer or monomers constituting the polyamide. Such polymers can be prepared by the simultaneous reaction of PE block and PA block precursors. The resulting polymers contain PE blocks and PA blocks, the length of which can vary greatly depending not only on the timing of the action of the chain regulator during the formation of the PA block but also on the presence of a variety of reactants that have reacted randomly and are distributed randomly (statistically) along the polymer chain.

[0175] The composition constituting the housing of the device according to the invention comprises from 0 to 30% by weight, preferably from 0.1 to 25% and more preferably from 5 to 20% of at least one impact modifier relative to the total weight of the composition.

[0176] additive

[0177] The composition constituting the housing of the device according to the invention may also comprise from 0 to 20% of additives.

[0178] Preferably, the additives present in the composition forming the shell are chosen from heat stabilizers, plasticizers, lubricants, organic or inorganic pigments, anti-UV agents, antistatic agents, mineral fillers, and organic fillers such as, for example, talc, calcium carbonate, titanium dioxide, zinc oxide and organic fillers.

[0179] Among the fillers, one may cite silica, titanium oxide or even glass beads.

[0180] The heat stabilizer may be selected from copper-based stabilizers, organic stabilizers, and mixtures thereof.

[0181] Copper-based stabilizers may be composed of one or more components selected from copper-based compounds such as cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, cuprous iodide, cupric iodide, cuprous acetate, and cupric acetate. Other metals such as silver halides and acetates may be mentioned. These copper-based compounds are typically accompanied by alkali metal halides. A well-known example is a mixture of CuI and KI, wherein the CuI:KI ratio is typically between 1:5 and 1:15, inclusive. An example of such a stabilizer is Ciba's Polyadd P201. Further details on copper-containing stabilizers are found in U.S. Patent No. 2,705,227. More recently, copper-based stabilizers such as copper complexes such as Bruggemann's Bruggolen H3336, H3337, and H3373 have emerged. The copper-based stabilizer is selected from copper halides, copper acetate, copper halides or copper acetate mixed with at least one alkali metal halide, and mixtures thereof, preferably a mixture of copper iodide and potassium iodide (CuI / KI).

[0182] The organic stabilizer may be selected from the group consisting of, without being limited to, the following list:

[0183] - phenolic antioxidants, for example Irganox 245, Irganox 1010, Irganox 1098 from Ciba, Irganox MD1024 from Ciba, Lowinox 44B25 from Great Lake;

[0184] - phosphorus-based stabilizers, for example phosphites, for example Irgafos 168 from Ciba;

[0185] - UV absorbers, such as Tinuvin 312 from Ciba,

[0186] -HAL, as mentioned before,

[0187] - amine type stabilizers such as Crompton's Naugard 445 or even hindered amine types such as Ciba's Tinuvin 770,

[0188] - Multifunctional stabilizers, such as Nylostab S-EED from Clariant.

[0189] Mixtures of two or more of these organic stabilizers are obviously conceivable.

[0190] The amount of heat stabilizer in the composition is preferably between 0.05 and 5% by weight relative to the total weight of the composition.

[0191] Preferably, the additive is present in the composition generally in a concentration ranging from 0.1 to 15% by weight, preferably from 1 to 15% by weight, relative to the total weight of the composition.

[0192] Depending on the location of the battery pack in the vehicle, one skilled in the art will know how to vary the amount of reinforcing fibers, impact modifiers, or additives. If the battery pack is located in the luggage compartment, the exterior compartment will be less exposed to the aggressive external environment. The percentage of fibers used for reinforcing and impact modification can be within the lower range of the claimed range. However, if the battery pack is in contact with ambient air, the amount of reinforcing fibers and impact modifiers will have to be higher, and the composition will have to include additives such as antioxidants or UV filters.

[0193] According to a preferred embodiment of the present invention, the shell is composed of a composition consisting of:

[0194] - 20 to 65% by weight, relative to the total weight of the composition, of reinforcing fibers having no thermally conductive properties,

[0195] - 0.1 to 30% by weight, relative to the total weight, of at least one impact modifier,

[0196] -0 to 30% flame retardant;

[0197] - 0 to 20% by weight of additives relative to the total weight of the composition.

[0198] The balance is a matrix comprising for the most part at least one polyamide.

[0199] According to another preferred embodiment of the present invention, the shell is composed of a composition comprising

[0200] - 20 to 65% by weight, relative to the total weight of the composition, of reinforcing fibers having no thermally conductive properties,

[0201] - 0.1 to 30% by weight, relative to the total weight, of at least one impact modifier,

[0202] -15 to 25% flame retardant,

[0203] - 0 to 20% by weight of additives relative to the total weight of the composition;

[0204] The balance is a matrix comprising for the most part at least one polyamide.

[0205] According to another preferred embodiment of the present invention, the housing is made of a composition comprising

[0206] - 40 to 65% by weight, relative to the total weight of the composition, of reinforcing fibers having no thermally conductive properties,

[0207] - 5 to 20% by weight, relative to the total weight, of at least one impact modifier,

[0208] -15 to 25% flame retardant;

[0209] - 1 to 20% by weight of additives relative to the total weight of the composition,

[0210] The balance is a matrix comprising for the most part at least one polyamide.

[0211] According to another preferred embodiment of the present invention, the shell is composed of a composition consisting of

[0212] - 40 to 65% by weight, relative to the total weight of the composition, of reinforcing fibers having no thermally conductive properties,

[0213] - 5 to 20% by weight, relative to the total weight, of at least one impact modifier,

[0214] -15 to 25% flame retardant;

[0215] - 1 to 20% by weight of additives relative to the total weight of the composition,

[0216] The balance is a matrix comprising for the most part at least one polyamide.

[0217] Inner shell

[0218] The inner shell, which is arranged opposite the battery pack and is intended to be in contact with the heat transfer fluid, is composed of a composition comprising:

[0219] - 5 to 65% by weight of reinforcing fibers relative to the total weight of the composition,

[0220] - when the reinforcing fibers used are thermally non-conductive, 10 to 20% by weight, relative to the total weight, of at least one thermally conductive component,

[0221] - at least one flame retardant, and

[0222] The remainder is a matrix comprising for the most part at least one polyamide chosen from semiaromatic polyamides and polyamides composed of units having an average number of carbon atoms per nitrogen atom ranging from 7 to 10, advantageously from 7.5 to 9.5.

[0223] polyamide

[0224] Suitable polyamides for the inner shell may be homopolyamides or copolyamides as defined above for the outer shell.

[0225] The lactams and amino acids used to make the homopolyamides must have an average number of carbon atoms per nitrogen atom of between 7 and 10. Advantageously, the lactams and amino acids are C10.

[0226] The monomers useful for obtaining the polyamide present in the matrix of the composition constituting the inner shell are chosen from the list of the polyamide of the outer layer.

[0227] According to a preferred embodiment, the polyamide of the inner layer is selected from PA610, PA410, PA412, PA612, PA1010, PA6T, PA6I, PA9T, PA10T, PA6T / 6I, PA6T / 10T, PA6T / 1010, PA10T / 1010 and mixtures thereof. Preferably, the polyamide constituting the inner shell matrix is ​​selected from PA 610, PA612, PA9T, PA10T and PA 1010.

[0228] Reinforcement fiber

[0229] The reinforcing fibers present in the composition constituting the inner shell are the same as those listed above for the outer shell.

[0230] Conductive components

[0231] The composition constituting the inner shell of the device according to the invention comprises from 10 to 20% by weight, preferably from 12 to 18% by weight, of at least one thermally conductive component relative to the total weight of the composition.

[0232] The thermally conductive component makes it possible to impart thermal conductivity to the polymer matrix receiving it, or also to increase its thermal conductivity.

[0233] The thermally conductive component may be selected from: carbon, carbon fibers, carbon black such as the carbon black sold under the trade name Ensaco 250G by Imerys, carbon nanotubes (denoted CNTs) such as the carbon black sold under the trade name MB by Arkema Carbon nanotubes sold in the form of expanded graphite such as C-THERM TM product lines, and in particular those marketed by Imery C-THERM TM 001 products, aluminum nitride, and boron nitride.

[0234] It is possible that the selected reinforcing fibers have thermally conductive properties, such as, for example, carbon fibers, CNTs, carbon nanofibers or graphene. In this case, the composition may not comprise a thermally conductive component.

[0235] flame retardants

[0236] The flame retardants present in the composition constituting the inner shell are the same as those listed above for the outer shell.

[0237] Impact modifiers

[0238] The impact modifiers present in the composition comprising the inner shell are the same as those listed above for the outer shell.

[0239] additive

[0240] The additives present in the inner shell composition are the same as those listed above for the outer shell.

[0241] According to a preferred embodiment of the present invention, the inner shell is composed of a composition comprising:

[0242] - 5 to 65% by weight of reinforcing fibers relative to the total weight of the composition,

[0243] - when the reinforcing fibers used are thermally non-conductive, 10 to 20% by weight, relative to the total weight, of at least one thermally conductive component,

[0244] -15 to 25% flame retardant;

[0245] - 0 to 30% by weight, relative to the total weight, of at least one impact modifier,

[0246] - 0 to 20% by weight of additives relative to the total weight of the composition,

[0247] The balance is a matrix comprising for the most part at least one polyamide.

[0248] According to a preferred embodiment of the present invention, the inner shell is composed of a composition comprising:

[0249] - 5 to 65% by weight of reinforcing fibers relative to the total weight of the composition,

[0250] - when the reinforcing fibers used are thermally non-conductive, 10 to 20% by weight, relative to the total weight, of at least one thermally conductive component,

[0251] -15 to 25% flame retardant;

[0252] - 5 to 20% by weight, relative to the total weight, of at least one impact modifier,

[0253] - 1 to 20% by weight of additives relative to the total weight of the composition,

[0254] The balance is a matrix comprising for the most part at least one polyamide.

[0255] According to a preferred embodiment of the present invention, the inner shell is composed of a composition consisting of:

[0256] - 5 to 65% by weight of reinforcing fibers relative to the total weight of the composition,

[0257] - when the reinforcing fibers used are thermally non-conductive, 10 to 20% by weight, relative to the total weight, of at least one thermally conductive component,

[0258] -15 to 25% flame retardant;

[0259] - 5 to 20% by weight, relative to the total weight, of at least one impact modifier,

[0260] - 1 to 20% by weight of additives relative to the total weight of the composition,

[0261] The balance is a matrix comprising for the most part at least one polyamide.

[0262] According to another preferred embodiment of the present invention, the inner shell is composed of a composition comprising:

[0263] - 5 to 65% by weight of reinforcing fibers having thermally conductive properties, relative to the total weight of the composition,

[0264] -15 to 25% flame retardant;

[0265] - 0 to 30% by weight, relative to the total weight, of at least one impact modifier,

[0266] - 0 to 20% by weight of additives relative to the total weight of the composition.

[0267] The balance is a matrix comprising for the most part at least one polyamide.

[0268] According to another preferred embodiment of the present invention, the inner shell is composed of a composition comprising:

[0269] - 5 to 65% by weight of reinforcing fibers having thermally conductive properties, relative to the total weight of the composition,

[0270] -15 to 25% flame retardant;

[0271] - 5 to 20% by weight, relative to the total weight, of at least one impact modifier,

[0272] - 1 to 20% by weight of additives relative to the total weight of the composition,

[0273] The balance is a matrix comprising for the most part at least one polyamide.

[0274] According to another preferred embodiment of the present invention, the inner shell is composed of a composition comprising:

[0275] - 5 to 65% by weight of reinforcing fibers having thermally conductive properties, relative to the total weight of the composition,

[0276] -15 to 25% flame retardant;

[0277] - 5 to 20% by weight, relative to the total weight, of at least one impact modifier,

[0278] - 1 to 20% by weight of additives relative to the total weight of the composition,

[0279] The balance is a matrix comprising for the most part at least one polyamide.

[0280] According to another preferred embodiment of the present invention, the inner shell consists of a composition consisting of:

[0281] - 5 to 65% by weight of reinforcing fibers having thermally conductive properties, relative to the total weight of the composition,

[0282] -15 to 25% flame retardant;

[0283] - 5 to 20% by weight, relative to the total weight, of at least one impact modifier,

[0284] - 1 to 20% by weight of additives relative to the total weight of the composition,

[0285] The balance is a matrix comprising for the most part at least one polyamide.

[0286] Advantageously, when the battery pack comprises a plurality of adjacent battery packs, the inner housing encapsulates the battery assembly by complementing the shape.

[0287] According to further features, the inner shell and the outer shell may be coated on the inside and / or outside with a layer having low water permeability.

[0288] By having one or more layers with low water permeability, a moisture barrier effect may be provided, which means that the battery pack is sealed against heat transfer fluids or the environment outside the device according to the invention.

[0289] For the purposes of the present invention, inner portion is understood to mean the layer arranged facing the heat transfer fluid channel.

[0290] Within the meaning of the present invention, external is understood to mean layers arranged facing the outside of the device according to the invention or facing the battery pack, as opposed to layers arranged facing the heat transfer fluid channels.

[0291] In particular, according to the embodiment in which the chosen heat transfer fluid is a liquid, such as a fluorinated compound, the layer with low water permeability serves, depending on its arrangement, to avoid leakage of the fluid towards the battery pack or towards the outside of the cooling and / or heating device.

[0292] According to a preferred embodiment, the layer(s) may be EVOH, a polyolefin, such as polypropylene or polyethylene: HDPE, LDPE.

[0293] Conductivity measurement

[0294] Preferably, the ratio of the thermal conductivity (λ) of the inner shell to the thermal conductivity (λ) of the outer shell is at least greater than 1.5, preferably in the range of 1.5 to 300, more particularly 2 to 100 and more preferentially 2 to 50.

[0295] Preferably, the thermal conductivity (λ) of the housing is less than or equal to 10 W.m -1 .K -1 , preferably between 0.1 and 10 W.m -1 .K -1 between 0.3 and 1 W.m -1 .K -1 between.

[0296] The thermal conductivity of the material is measured using the HOT DISK technique as described in the ISO 22007-2 standard.

[0297] The convection coefficient can also be used to qualify the heat transfer between the shell and the fluid flowing in the device. In devices according to the present invention, the outer shell allows little or no heat transfer between the fluid and the shell material. In contrast, the inner shell material is selected to allow maximum heat transfer between the inner shell near or in contact with the battery pack and the fluid.

[0298] Preparation method of composition

[0299] The invention also encompasses a process for the preparation of a composition such as the one defined above. According to this process, the composition can be prepared by any method that allows obtaining a homogeneous mixture containing the composition according to the invention and optionally other additives, such as melt extrusion, compaction or even a roll mixer when the size of the reinforcing fibers is taken into account.

[0300] Advantageously, customary apparatuses from the thermoplastics industry for mixing or kneading are used, such as extruders, for example twin-screw type extruders, and kneaders, for example BUSS co-kneaders.

[0301] Method for manufacturing device

[0302] Depending on the fiber size, battery devices according to the present invention can be manufactured by various techniques.

[0303] When the fibers are short, the battery device according to the invention can be obtained by injection, extrusion, coextrusion, thermocompression and multi-injection of at least one composition, such as the composition defined above.

[0304] When the fibers are long or continuous, the battery device according to the present invention can be manufactured by a variety of techniques selected from the following: pultrusion, filament winding, thermocompression, injection molding, resin transfer molding (RTM), structured reaction and injection molding (S-RIM) or injection-compression molding. Specific closed mold techniques are RTM or S-RIM or injection-compression. The term "resin" in RTM here refers to the composition according to the present invention without reinforcing fibers.

[0305] According to a specific embodiment, the manufacturing method may include:

[0306] - a step of applying the reinforcing fibers in the mold, and then

[0307] - at least one step of impregnation of said fibers with a precursor composition of the composition according to the invention.

[0308] loop

[0309] The invention also relates to a cooling and / or heating circuit for an electric or hybrid motor vehicle battery pack comprising a main circulation loop of a heat transfer fluid, provided with means intended for circulating the heat transfer fluid in the main loop.

[0310] Further, the main loop is connected to a reversible heat pump and a cooling and / or heating device such as those described above.

[0311] According to various embodiments, the heat transfer fluid is selected from gases such as air, liquids such as glycol water, hydrocarbon compounds, hydrofluorocarbons, ethers, hydrofluoroethers, CO2, NH3, SO2 and fluoroolefins.

[0312] Preferably, the refrigerant is selected from hydrocarbon compounds, hydrofluorocarbons, ethers, hydrofluoroethers, halocarbons, CO2, NH3, SO2 and fluoroolefins.

[0313] In one embodiment, the heat transfer fluid is a refrigerant fluid selected from the group consisting of CO2, haloalkanes, haloolefins, fluoropropenes, fluoropropanes and fluoroethanes, preferably selected from the group consisting of 1,3,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoropropene, 1,2,3,3,3-pentafluoropropene, 1,1,3,3-tetrafluoropropene, 3,3,3-trifluoropropene, 2,3,3-trifluoropropene, 1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, pentafluoroethane, difluoromethane , 1,1-difluoroethane, 1,1,1,2,3,3,3-heptafluoropropane, 1,1,1-trifluoropropane, 1,1,1,3,3,3-hexafluoropropane, 1,1,1,3,3-pentafluoropropane, 1,1,1,3,3-pentafluorobutane, 1,1,1,4,4,4-hexafluorobut-2-ene, trifluoroiodomethane, 1-chloro-3,3,3-trifluoropropene, 1-chloro-2,3,3,3-tetrafluoropropene, 1-chloro-2,3,3,3-tetrafluoropropene and mixtures thereof.

[0314] In the context of the present invention, "HFO-1234yf" refers to 2,3,3,3-tetrafluoropropene, "HCFO-1233zd" refers to 1-chloro-3,3,3-trifluoropropene, "HCFO-1224yd" refers to 1-chloro-2,3,3,3-tetrafluoropropene, and "HFO-1336mzz" refers to 1,1,1,4,4,4-hexafluorobut-2-ene.

[0315] In a preferred embodiment, the heat transfer fluid is a refrigerant selected from 1,3,3,3-tetrafluoropropene (1234ze), 2,3,3,3-tetrafluoropropene (HFO-1234yf or 1234yf), difluoromethane (HFC-32), alone or in combination; in particular, the heat transfer fluid is 2,3,3,3-tetrafluoropropene (1234yf) and difluoromethane.

[0316] The heat transfer fluid may be a mixture of 2,3,3,3-tetrafluoropropene (HFO-1234yf) and difluoromethane (HFC-32) in the following proportions: 20 to 95 weight percent HFO-1234yf relative to the total weight of the mixture, with HFC-32 making up to 100%. The transfer fluid may be one of the following mixtures: 27.5 / 72.5; 35 / 65; 42.5 / 57.5; 45 / 55; 55 / 45; 57.5 / 42.5; 70 / 30; 78.5 / 21.5; 80 / 20; and 90 / 10 HFO-1234yf / HFC-32, in weight percent relative to the total weight of the mixture.

[0317] Advantageously, the refrigerant fluid comprises a lubricant, which is preferably selected from mineral oils, silicone oils, natural paraffins, cycloalkanes, synthetic paraffins, alkylbenzenes, polyalphaolefins, polyalkylene glycols, polyol esters and / or polyvinyl ethers; the lubricant is in a more particularly preferred manner a polyalkylene glycol or a polyol ester.

[0318] According to a characteristic of the invention, the circuit may comprise at least one secondary circuit connected to the primary circuit, one or more secondary circuits being connected to the passenger compartment of the motor vehicle and / or to an electronic circuit connected to the electric motor of the motor vehicle and / or to the internal combustion engine of the motor vehicle (when the motor vehicle is of hybrid type).

[0319] Advantageously, the circuit may comprise control means configured to control the transfer of heat from the primary loop to at least one secondary loop (such as defined above).

[0320] Other objects, advantages and features will emerge from the following description, given as a purely illustrative example and made with reference to the accompanying drawings, in which:

[0321] Figure 1 A cross-sectional view of a cooling and / or heating device for a battery pack of an electric or hybrid motor vehicle, the device comprising an inner housing and an outer housing.

[0322] Figure 2 A cross-sectional view of a portion of a cooling and / or heating device for a battery pack of an electric or hybrid automotive vehicle, the device comprising an inner and outer housing, and wherein Figure 2 Display as Figure 1 Alternative housing configurations to the housing shown in .

[0323] Figures 1 to 2 Two embodiments of the cooling and / or heating device according to the invention for a battery pack of an electric vehicle or a hybrid vehicle are shown.

[0324] exist Figure 1 In FIG, a cooling and / or heating device 1 according to the present invention is shown comprising two shells. An inner shell 2 is arranged facing a battery pack 3. An outer shell 4 forms with the inner shell 2 a channel intended for the flow of a heat transfer fluid 5. The device 1 is provided with an inlet 6 and an outlet 7 for the passage of the heat transfer fluid 5.

[0325] In the embodiment shown, a space 8 is provided between the battery pack 3 and the inner casing 2. According to an alternative, the inner casing 2 may be arranged to at least partially contact the battery pack to optimize heat transfer between the battery pack 3 and the heat transfer fluid 5.

[0326] Conventionally, the battery pack 3 comprises a plurality of adjacent battery packs. Figure 2 In another embodiment shown in FIG, the inner housing 2 is inserted between two adjacent battery packs. Figure 2Schematically, a portion of a battery pack 3 is shown, comprising three identical battery packs 9, 10, and 11. Reference will be made to adjacent packs 9 and 10, each comprising four walls 9a, 9b, 9c, 9d and 10a, 10b, 10c, 10d, respectively. In the embodiment shown, the inner shell 2 is arranged so as to partially face the walls 9a, 9b, 9c, 9d of pack 9 and the walls 10a, 10b, 10c, 10d of pack 10.

[0327] Thus, the inner shell 2 extends closest to the cell packs 3 to follow their shape, thus allowing improved heat transfer between the battery pack 3 and the heat transfer fluid 5 for better energy recovery. Advantageously, such a shell 2 adapted to the complex geometry of the battery pack 3 can be easily and quickly manufactured thanks to the polyamide composition.

[0328] Advantageously, the inner and outer shells may be coated with a layer having low water permeability. The layer or layers (not shown) may be internal or external.

[0329] Preferably, at least one layer with low water permeability is arranged in contact on the inside with the inner shell 2 , ie with the heat transfer fluid 5 .

[0330] The function of the heat transfer fluid 5 is to transfer heat between two or more temperature sources. The fluid can be a gas, air or even a liquid.

[0331] Figure 3 A circuit according to a specific embodiment of the present invention is described. Circuit 20 comprises a device 21 according to the present invention, enclosing a battery pack, an expansion valve 22, a heat exchanger 23, a four-way valve 24, and a compressor 25. Heat exchanger 23 is of the air / heat transfer fluid type, preferably a refrigerant. The refrigerant of circuit 20 and the air flow supplied by the fan pass through heat exchanger 23. Some or all of this same air flow can, for example, be passed through a heat exchanger (not shown) for the cooling system of the internal combustion engine of a hybrid vehicle or through the passenger compartment. For a hybrid vehicle, the direction of the air flow depends on the operating mode of circuit 20, the requirements of the battery pack, and the requirements of the internal combustion engine.

[0332] In cooling mode, i.e. when the battery pack generates heat, the refrigerant mobilized by the compressor 25 passes through the valve 24, then through the device 21 acting as a condenser (i.e. it rejects heat to the outside), then through the expansion valve 22, then through the exchanger 23 acting as an evaporator, thus allowing the air flow intended to pulse inside the passenger compartment of the motor vehicle to be cooled.

[0333] In heat pump mode, i.e. when the battery pack needs to be heated, for example during startup, the refrigerant flow direction is reversed via valve 24. Heat exchanger 23 acts as a condenser, while device 21 acts as an evaporator. Heat exchanger 23 then makes it possible to heat the air flow intended for the passenger compartment of the motor vehicle.

[0334] The heat exchanger of the cooling circuit can be activated by means of said valve as required by the internal combustion engine (heating the air entering the engine or recovering energy generated by the engine).

[0335] In addition, the vapor compression circuit may include different branches with separate heat exchangers, wherein the refrigerant flows through these branches or not, depending on the operating mode. Optionally, alternatively or additionally, the vapor compression circuit may include means for changing the direction of the refrigerant flow, including, for example, one or more three-way or four-way valves.

[0336] Figure 4 A circuit according to another embodiment of the present invention is described. Circuit 30 includes two heat transfer fluid circulation loops 32 and 36: one loop 32 in which air circulates, and one loop 36 in which a refrigerant circulates. Loop 32 includes a device 31 according to the present invention that encloses a battery pack and an air / fluid heat exchanger 33. Loop 32 includes an air flow for heating or cooling the battery pack. A fan may be introduced into the loop to circulate the air. Heat exchanger 33 is also part of loop 36, which includes a compressor 34, a heat exchanger 35, and an expansion valve 37. In the specific case of a hybrid vehicle, heat exchanger 35 may be connected to the vehicle's passenger compartment or heat engine.

Claims

1. Devices for use in cooling and / or heating circuits for battery packs of electric or hybrid electric vehicles, comprising: - a housing consisting of a composition comprising: - 20 to 65% by weight, relative to the total weight of the composition, of reinforcing fibers having no thermally conductive properties, - the balance being a matrix comprising more than 50% of at least one polyamide, and an inner casing, arranged opposite the battery pack and intended to be in contact with the cooling fluid, the inner casing consisting of a composition comprising: - 5 to 65% by weight of reinforcing fibers relative to the total weight of the composition, - when the reinforcing fibers used are thermally non-conductive, 10 to 20% by weight, relative to the total weight, of at least one thermally conductive component, - at least one flame retardant, and - the balance being a matrix of polyamides comprising more than 50% of at least one polyamide chosen from semiaromatic polyamides and polyamides composed of units having an average number of carbon atoms per nitrogen atom ranging from 7 to 10, - heat transfer fluid inlet; and - heat transfer fluid outlet, The device defines a cooling and / or heating volume for the battery pack, wherein the outer shell and the inner shell form a channel intended for the flow of a heat transfer fluid, The shell allows little or no heat transfer between the fluid and the shell material, and the thermal conductivity (λ) of the shell is less than or equal to 10 W.m -1 .K -1 .

2. The device according to claim 1, characterized in that In the case of the inner shell, the balance is a matrix comprising more than 50% of at least one polyamide chosen from semiaromatic polyamides and polyamides composed of units having an average number of carbon atoms per nitrogen atom ranging from 7.5 to 9.

5.

3. The device according to claim 1, characterized in that The thermal conductivity (λ) of the housing is between 0.1 and 10 W.m -1 .K -1 between.

4. The device according to claim 1, characterized in that The thermal conductivity (λ) of the housing is between 0.3 and 1 W.m -1 .K -1 between.

5. The device according to claim 1, characterized in that The shell comprises a polyamide matrix including at least one polyamide selected from semiaromatic polyamides and polyamides composed of units having an average number of carbon atoms per nitrogen atom ranging from 9 to 18.

6. The device according to any one of claims 1 to 5, characterized in that The housing comprises a polyamide matrix comprising at least one selected from the group consisting of PA612, PA1010, PA10T, PA10T / 1010, PA11, PA12, PA11 / 10T, PA12 / 10T, PA 1012, PA618, PA 12T, PA 1010 / 1012, PABACT / 6T, PABACT / 10T, PA BACT / 12T, PAMPMDT / 6T, PA MPMDT / 10T, PA MPMDT / 12T, PA MXDT / 6T, PAMXDT / 10T, PA MXDT / 12T, PA11 / BACT / 6T, PA11 / BACT / 10T, PA 11 / BACT / 12T, PA 11 / MPMDT / 6T, PA11 / MPMDT / 10T, PA 11 / MPMDT / 12T, PA Polyamides of PA11 / MXDT / 6T, PA11 / MXDT / 10T, PA 11 / MXDT / 12T and mixtures thereof.

7. The device according to claim 6, characterized in that The housing comprises a polyamide matrix including at least one polyamide selected from the group consisting of PA12, PA11, PA10.10, PA10.12 and PA11 / 10.T.

8. The device according to any one of claims 1 to 5, characterized in that The inner shell comprises a polyamide matrix including at least one polyamide selected from the group consisting of PA610, PA410, PA412, PA612, PA1010, PA6T, PA6I, PA9T, PA10T, PA6T / 6I, PA6T / 10T, PA6T / 1010, PA10T / 1010 and mixtures thereof.

9. The device according to any one of claims 1 to 5, characterized in that The reinforcing fibers not having thermally conductive properties present in the composition constituting the outer shell are chosen from glass fibers, basalt fibers and aramid fibers.

10. The device according to any one of claims 1 to 5, characterized in that The reinforcing fibers having thermally conductive properties present in the composition constituting the inner shell are chosen from carbon, carbon fibers, carbon black, carbon nanotubes, expanded graphite, aluminum nitride and boron nitride.

11. The device according to any one of claims 1 to 5, characterized in that: The ratio of the thermal conductivity (λ) of the inner shell to the thermal conductivity (λ) of the outer shell is at least greater than 1.

5.

12. The device according to any one of claims 1 to 5, characterized in that The flame retardant present in the composition constituting the inner and outer shells is: a metal salt selected from metal salts of phosphinic acid, metal salts of diphosphinic acid, polymers containing at least one metal salt of phosphinic acid, polymers containing at least one metal salt of diphosphinic acid; red phosphorus, antimony oxide, zinc oxide, iron oxide, magnesium oxide, metal borates, or melamine pyrophosphate, melamine cyanurate, siliconized or fluorinated anti-drip agents, and mixtures thereof.

13. The device according to claim 12, characterized in that The metal borate is zinc borate.

14. The device according to any one of claims 1 to 5, characterized in that When the battery pack (3) includes a plurality of adjacent battery packs (10, 11), the inner case (2) encapsulates the battery assembly by complementing the shape.

15. The device according to any one of claims 1 to 5, characterized in that The inner shell (2) and / or the outer shell (4) are coated on the inside and / or outside with a layer having low water permeability.

16. Use of a device as defined in any one of claims 1 to 15 for cooling and / or heating a battery pack of an electric or hybrid motor vehicle by means of a refrigerant selected from the group consisting of hydrocarbons, ethers, halogenated hydrocarbons, CO2, NH3, SO2.

17. The use according to claim 16, characterized in that The halocarbon is a fluoroolefin.

18. The use according to claim 16, characterized in that The refrigerant is selected from the group consisting of CO2, haloalkanes, haloalkenes, and mixtures thereof.

19. The use according to claim 18, characterized in that The haloalkane is selected from fluoropropane and fluoroethane.

20. The use according to claim 18, characterized in that The haloolefin is a fluoropropene.

21. The use according to any one of claims 18 to 20, characterized in that The refrigerant is selected so that the heat transfer fluid is a refrigerant selected from 1,3,3,3-tetrafluoropropene (1234ze), 2,3,3,3-tetrafluoropropene (1234yf), difluoromethane, 1-chloro-3,3,3,3-tetrafluoropropene (HCFO-1233zd), 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd), 1,1,1,4,4,4-hexafluorobut-2-ene (HFO-1336mzz), alone or in combination.

22. The use according to any one of claims 16 to 21, characterized in that The refrigerant fluid contains a lubricant.

23. A cooling and / or heating circuit for a battery pack of an electric or hybrid motor vehicle, comprising a main circulation circuit for a heat transfer fluid provided with means intended to circulate the heat transfer fluid in the main circuit, said cooling and / or heating circuit being characterized in that the main circuit is connected to a reversible heat pump and to a cooling and / or heating device as defined in any one of claims 1 to 15.

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