Device for cooling and / or heating an electric vehicle battery

Abstract

Device for cooling and / or heating an electric vehicle battery. The invention relates to a device intended to be used in a cooling and / or heating circuit of an electric or hybrid motor vehicle battery, comprising: - an outer casing consisting of a composition comprising: - from 20 to 65% by weight relative to the total weight of the composition of reinforcing fibers, which do not have thermal conduction properties - the remainder being a matrix predominantly comprising at least one polyamide and - an inner casing arranged opposite the battery and intended to be in contact with a refrigerant fluid consisting of a composition comprising: - from 5 to 65% by weight relative to the total weight of the composition of reinforcing fibers, - from 10 to 20% by weight relative to the total weight of at least one thermally conductive component, when the reinforcing fibers used are not thermally conductive,- at least one flame retardant, and - the complement being a matrix comprising mainly at least one polyamide chosen from semi-aromatic 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 - a heat transfer fluid inlet; and - a heat transfer fluid outlet, the device delimiting a cooling and / or heating volume of the battery. Figure for the abstract: no figure,

Description

Title of the invention: Device for cooling and / or heating an electric vehicle battery FIELD OF THE INVENTION

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

[0002] The invention relates, more specifically, to a device for cooling and / or heating a battery for an electric or hybrid motor vehicle. TECHNICAL BACKGROUND

[0003] One of the goals sought in this automotive field is to offer vehicles that are less and less polluting. Thus, electric or hybrid vehicles with a battery aim to gradually replace thermal vehicles, such as gasoline or diesel vehicles. However, it turns out that the battery is a relatively complex component of the vehicle. Depending on the location of the battery in the vehicle, it may be necessary to protect it from impacts and the external environment, which may be at extreme temperatures and variable humidity. It is also necessary to avoid any risk of flames.

[0004] Furthermore, it is important that its operating temperature does not exceed 55°C so as not to damage the battery cells and preserve its lifespan. Conversely, for example in winter, it may be necessary to raise the temperature of the battery in order to optimize its operation.

[0005] The electric or hybrid motor vehicle thus requires a device for cooling and / or heating the battery. Devices for cooling a battery, consisting of the circulation of a heat transfer fluid around the battery are known, as are batteries comprising a protective case. In particular, batteries are currently equipped with a metal case. Furthermore, the shapes given to a metal structure are obtained by a stamping process. However, when the shape of the case is complex, due to its location for example, the stamping process is not the most efficient for obtaining this type of specificity. This case also has the disadvantage of being relatively heavy and of degrading relatively quickly over time, particularly if it is located in a humid environment.

[0006] Thus, a light and resistant structure is sought which can both protect the battery from the external environment and act as a heat exchanger. Thus, the elements of the device must: - be impermeable to the fluids transported and therefore have barrier properties with respect 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 property" means that the structure is impermeable to the fluids of automotive air conditioning lines and therefore does not allow the emission of air conditioning line fluids into the atmosphere. - have chemical resistance to the fluids transported, as well as to compressor oils, water and oxygen, in order to avoid excessive degradation over the long term; - not only present sufficient mechanical resistance (in particular burst resistance) and allow vibration damping; - have satisfactory thermal resistance, taking into account that the fluids transported may be at a high temperature, and that the temperature of the environment may also be high (in particular in automotive air conditioning, the parts concerned may be located near the engine) and in particular ZnC12.

[0007] Thus, materials are sought to replace known metal structures, which meet the specific specifications mentioned above and aim to improve the heat transfer taking place between the battery and the heat transfer fluid in a device for cooling and / or heating a battery. Summary of the invention

[0008] These aims are achieved by means of a device intended to be used in a cooling and / or heating circuit of an electric or hybrid motor vehicle battery, comprising: - an outer envelope consisting of a composition comprising: - from 20 to 65% by weight relative to the total weight of the composition of reinforcing fibers, which do not have thermal conduction properties, - the complement being a matrix comprising mainly at least one polyamide and - an internal envelope arranged opposite the battery and intended to be in contact with a heat transfer fluid consisting of a composition comprising: - from 5 to 65% by weight relative to the total weight of the composition of reinforcing fibers, - from 10 to 20% by weight relative to the total weight of at least one thermally conductive component, when the reinforcing fibers used are not thermally conductive, - at least one flame retardant, and -the complement being a matrix comprising mainly at least one polyamide chosen from semi-aromatic 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; - a heat transfer fluid inlet; and - a heat transfer fluid outlet, the device delimiting a cooling and / or heating volume of the battery.

[0009] The device for cooling and / or heating a battery according to the invention has the advantage of being lighter than a device comprising a metal structure. This weight saving contributes to the energy or fuel savings sought for so-called clean vehicles.

[0010] Depending on its location in the vehicle, this device may come into contact with an aggressive environment, such as a high temperature in summer or a very low temperature in winter, contact with zinc chloride, shocks, or even significant humidity. It has been observed that the device according to the invention has satisfactory resistance to these external constraints.

[0011] Furthermore, it has been observed that, depending on the car manufacturer, the shape of the batteries can vary. Indeed, manufacturers are seeking to house this battery in spaces that have been unused or relatively unusable until now. However, shaping a plastic material by molding or injection is much easier to achieve than shaping a metal plate. BRIEF DESCRIPTION OF THE FIGURES

[0012] [Fig. 1] is a sectional view of a device for cooling and / or heating a battery for an electric or hybrid motor vehicle.

[0013] [Fig.2] is a sectional view of a portion of a cooling device and / or heating a battery for an electric or hybrid motor vehicle, [Fig.2] illustrating a configuration of the external envelope alternative to the external envelope illustrated in [Fig.l].

[0014] [Fig.3] represents a cooling and / or heating circuit of a battery incorporating the device according to the invention.

[0015] [Fig.4] represents a cooling and / or heating circuit of a battery incorporating the device according to the invention, comprising two heat transfer loops. DETAILED DESCRIPTION

[0016] Other characteristics, aspects, objects and advantages of the present invention will appear even more clearly on reading the description and the examples which follow.

[0017] It is further specified that the expressions "between... and..." and "from... to..." used in the present description must be understood as including each of the limits mentioned.

[0018] THE DEVICE

[0019] The device according to the invention comprises: - an external envelope, -an internal envelope, - a heat transfer fluid inlet; and - a heat transfer fluid outlet, the device delimiting a cooling and / or heating volume of the battery.

[0020] OUTER ENVELOPE

[0021] The outer envelope is made of a composition comprising: - from 20 to 65% by weight relative to the total weight of the reinforcing fiber composition, -the complement being a matrix comprising mainly at least one polyamide.

[0022] POLYAMIDES

[0023] The term polyamide designates both a homopolyamide and a copolyamide.

[0024] The nomenclature used to define polyamides is described in the standard ISO 1874-1:2011 "Plastics - Polyamide (PA) materials for molding and extrusion - Part 1: Designation", in particular on page 3 (tables 1 and 2) and is well known to those skilled in the art.

[0025] The polyamide can be obtained from the polycondensation of lactam units, amino acid units and / or XY units, X denoting a diamine and Y denoting a dicarboxylic acid (or diacid).

[0026] The lactams and amino acids contain from 4 to 12 carbon atoms. Preferably, they are chosen from pyrrolidinone, 2-piperidinone, caprolactam, aminohexanoic acid, pelargolactam, decanolactam, undecanolactam, 10-aminoundecanoic acid, amino-11-undecanoic acid, amino-12-dodecanoic acid, lauryllactam, enantholactam, caprylolactam.

[0027] Advantageously, the lactams and the amino acids are C11 and C12.

[0028] The diamine may be aliphatic, linear or branched, or cycloaliphatic, preferably it is linear or branched aliphatic, in particular linear. The dicarboxylic acid may be aliphatic, cycloaliphatic or aromatic, preferably it is aliphatic or aromatic.

[0029] Concerning the polyamides obtained from the polycondensation of XY units, the diamine (X) can be C4 to C36, in particular C6 to C22, in particular C6 to C18 and the dicarboxylic acid (Y) in C4 to C36, in particular in C6 to C22, in particular in C6 to C18.

[0030] Advantageously, the diamine is chosen from 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 diamines obtained from fatty acids, 1,3-xylylenediamine (denoted MXD) and 1,4-xylylenediamine (denoted PXD), bis(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 commonly called "BMACM" or "MACM" (and noted B hereinafter), p-bis(aminocyclohexyl)-methane commonly called "PACM" (and noted P hereinafter), isopropylidenedi(cyclohexylamine) commonly called "PACP", isophorone-diamine (noted IPD hereinafter) and 2,6-bis(amino methyl)norbornane commonly called "BAMN", in particular 1,10-decanediamine.

[0031] A non-exhaustive list of cycloaliphatic diamines is given in the publication "Cycloaliphatic Amines" (Encyclopaedia of Chemical Technology, Kirk-Othmer, 4th Edition (1992), pp. 386-405).

[0032] Advantageously, the dicarboxylic acid is chosen from succinic acid, pentanedioic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassylic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanoic acid, octadecenoic acid, eicosanedioic acid, docosanedioic acid and fatty acid dimers containing 36 carbons, terephthalic acid (denoted T), isophthalic acid (denoted I), in particular dodecanedioic acid.

[0033] Advantageously, the diamine is chosen 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 chosen from sebacic acid, undecanedioic acid, dodecanedioic acid, brassylic acid, tetradecanedioic acid, terephthalic acid. (noted T), isophthalic acid (noted I), in particular dodecanedioic acid.

[0034] More advantageously, the lactam is lauryllactam, the amino acid is chosen from 10-aminoundecanoic acid, amino-11-undecanoic acid, amino-12-dodecanoic acid, the diamine is chosen from 2-methyl-1,5-pentanediamine, 1,6-hexamethylenediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine, 1,10-decanediamine and 1,12-dodecanediamine and the dicarboxylic acid is chosen from adipic acid, sebacic acid, dodecanedioic acid, terephthalic acid (denoted T) and isophthalic acid (denoted I).

[0035] According to a very preferred embodiment, the lactam is lauryllactam, the amino acid is chosen from 10-aminoundecanoic acid, amino-11-undecanoic acid, amino-12-dodecanoic acid, the diamine is chosen from 2-methyl-1,5-pentanediamine, 1,6-hexamethylenediamine, 1,10-decanediamine and 1,12-dodecanediamine and the dicarboxylic acid is chosen from adipic acid, sebacic acid, dodecanedioic acid, terephthalic acid (denoted T) and isophthalic acid (denoted I).

[0036] Preferably, the outer envelope comprises a polyamide matrix comprising at least one polyamide chosen from semi-aromatic polyamides and polyamides consisting of units having an average number of carbon atoms per nitrogen atom ranging from 9 to 18.

[0037] By average number of carbon atoms per nitrogen atom, we mean the average of the number of carbon atoms per unit, that is to say per chain between two nitrogen atoms. Within a polyamide, the units are linked to each other by amide functions: -CO-NH-. Thus, there are as many nitrogen atoms as there are amide groups (-CO-NH-). In the case of a homopolyamide of type PA-XY, the number of carbon atoms per nitrogen atom is the average of the unit X and the unit Y. Thus PA612 resulting from the polycondensation of hexanediamine and dodecanedioic acid, is a PA with 9 carbon atoms per nitrogen atom, in other words is a C9 PA, according to 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. The calculation is carried out in molar proportion to the different amide units. Thus, coPA-6.T / 6.6 comprising 60% 6T and 40% 66 is in C6.6: 60%x[(6+8) / 2]+40%x[(6+6) / 2] = 6.6. Advantageously, the polyamide present in the composition of the external envelope is chosen from PA612, PA1010, PA10T, PA10T / 1010, PAU, PA12, PA11 / 10T, PA12 / 10T, PA 1012, PA 618, PA 12T, PA 1010 / 1012, PA BACT / 6T, PA BACT / 10T, PA BACT / 12T, PA MPMDT / 6T, PA MPMDT / 10T, PA MPMDT / 12T, PA MXDT / 6T, PA MXDT / 10T, PA MXDT / 12T, PA11 / BACT / 6T, PA 11 / BACT / 10T, PA 11 / BACT / 12T, PA 11 / MPMDT / 6T, PA 11 / MPMDT / 10T, PA 11 / MPMDT / 12T, PA 11 / MXDT / 6T, PA 11 / MXDT / 10T, PA 11 / MXDT / 12T, and their mixture. Preferably, the polyamide constituting the matrix of the external envelope is chosen from PA 12, PA 11, PA 1010, PA 1012 and PA11 / 10T.

[0039] By majority, within the meaning of the present invention, is meant a proportion greater than 50% of polyamide within the matrix of the composition. Preferably, the polyamide(s) represent from 50 to 80% by weight, relative to the total weight of the matrix.

[0040] According to a preferred embodiment, the composition of the external envelope comprises more than 25% by weight of polyamide relative to the total weight of the composition.

[0041] REINFORCING FIBERS

[0042] The composition constituting an external envelope according to the invention comprises from 20 to 65% by weight relative to the total weight of the composition of reinforcing fibers.

[0043] The fibers present in the composition of the envelope may be of different dimensions. The reinforcing fibers may be described as short, long or continuous fibers. A mixture of these fibers of different dimensions and / or of different nature may also be used.

[0044] Preferably, the so-called short fibers have a length of between 200 and 400 μm. The so-called long fibers preferably have a length greater than 1000 μm. The length of the glass fibers is measured according to the ISO 22314:2006(E) standard.

[0045] These reinforcing fibers can be chosen from: - mineral fibers, these having high melting temperatures Tf and higher than the melting temperature Tf of said polyamide present in the matrix of the composition of the envelope according to the invention and higher than the polymerization and / or processing temperature, - polymeric or polymer fibers having a melting temperature Tf' or, failing Tf', a glass transition temperature Tg', higher than the polymerization temperature or higher than the melting temperature Tf of said polyamide present in the matrix of the composition of the envelope according to the invention and higher than the processing temperature, - natural fibers, - or mixtures of the fibers mentioned above.

[0046] As mineral fibers suitable for the invention, mention may be made of carbon fibers, which includes nanotube fibers or carbon nanotubes (CNTs), carbon nanofibers or graphenes; silica fibers such as glass fibers, in particular of 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 based on metals and / or their alloys; fibers of metal oxides, in particular alumina (A12O3); metallized fibers such as fibers metallized glass fibers and metallized carbon fibers or mixtures of the aforementioned fibers.

[0047] As polymeric fibers suitable for the invention, mention may be made of: - the fibers based on amorphous thermoplastic polymer and have a glass transition temperature Tg higher than the Tg of the polyamide or mixture of polyamides present in the matrix, when the latter is amorphous; or higher than the Tf of the polyamide or mixture of polyamides present in the matrix, when the latter is semi-crystalline. Advantageously, they are based on semi-crystalline thermoplastic polymer and have a melting temperature Tf higher than the Tg of the polyamide or mixture of polyamides present in the matrix, when the latter is amorphous; or higher than the Tf of the polyamide or mixture of polyamides present in the matrix when the latter is semi-crystalline. Thus, there is no risk of melting for the organic fibers constituting the reinforcing material during impregnation by the thermoplastic matrix of the final composite. -thermosetting polymer fibers and more particularly chosen from: unsaturated polyesters, epoxy resins, vinyl esters, phenolic resins, polyurethanes, cyanoacrylates and polyimides, such as bis-maleimide resins, aminoplasts resulting from the reaction of an amine such as melamine with an aldehyde such as glyoxal or formaldehyde, - thermoplastic polymer fibers and more particularly chosen from: polyethylene terephthalate (PET), polybutylene terephthalate (PBT), - polyamide fibers, - aramid fibers (such as Kevlar®) and aromatic polyamides such as those corresponding to one of the formulas: PPDT, MPDI, PAA and PPA, with PPD and MPD being respectively p- and m-phenylenediamine, PAA being polyarylamides and PPA being polyphthalamides, - polyamide block copolymer fibers such as polyamide / polyether, polyarylether ketone (PAEK) fibers such as polyetherether ketone (PEEK), polyetherketone ketone (PEKK), polyetherketoneetherketone ketone (PEKEKK).

[0048] Among the fibers of natural origin, and in particular plant origin, mention may be made of fibers based on flax, castor oil, wood, kenaf, coconut, hemp, jute, lignin, bamboo, silk, in particular spider silk, sisal, and other cellulosic fibers, in particular viscose. These fibers of plant origin can be used pure, treated or coated with a coating layer, in order to facilitate the adhesion and impregnation of the polymer matrix.

[0049] The reinforcing fibers may constitute a fibrous material, which may also be a fabric, braided or woven with fibers.

[0050] It can also correspond to fibers with holding threads. These constituent fibers can be used alone or in mixtures. Thus, organic fibers can be mixed with mineral fibers to be impregnated with the polymer matrix and form the pre-impregnated fibrous material.

[0051] The organic fiber strands can have several weights. They can also have several geometries. The fibers can be in the form of short fibers, which then make up the felts or nonwovens which can be in the form of strips, sheets, or pieces, or in the form of continuous fibers, which make up 2D fabrics, braids or strands of unidirectional (UD) or nonwoven fibers. The fibers constituting the fibrous material can also be in the form of a mixture of these reinforcing fibers of different geometries.

[0052] Preferably, the fibrous material consists of continuous carbon, glass or silicon carbide fibers or their mixture, in particular carbon fibers. It is used in the form of a strand or several strands.

[0053] The preferred short reinforcing fibers are short fibers chosen from: carbon fibers, including metallized, glass fibers, including metallized of type E, R, S2, aramid fibers (such as Kevlar®) or aromatic polyamides, polyarylether ketone fibers (PAEK), such as polyetherether ketone (PEEK), polyetherketone ketone fibers (PEKK), polyetherketoneetherketone ketone fibers (PEKEKK) or mixtures thereof.

[0054] Preferably, the reinforcing fibers are selected from glass, carbon, ceramic, aramid fibers or their mixtures.

[0055] Preferably, the external envelope of the device according to the invention has heat-insulating properties. According to this preferred embodiment, the reinforcing fibers will preferably be chosen from glass fibers, basalt fibers, aramid fibers.

[0056] Depending on the size of the fibers used: short, long or continuous, the content of reinforcing fibers may be different in the composition.

[0057] 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 preferably between 40 and 65% by weight of reinforcing fibers.

[0058] FIRE RETARDANTS

[0059] The composition constituting the external envelope of the device according to the invention may comprise at least one flame retardant agent.

[0060] Preferably, the flame retardant is chosen from halogen-free flame retardants, as described in US 2008 / 0274355 and in particular a metal salt chosen from a metal salt of phosphinic acid, a metal salt of diphosphinic acid, a polymer containing at least one metal salt of phosphinic acid, a polymer containing at least one metal salt of diphosphinic acid. The flame retardant may also be chosen from red phosphorus, antimony oxide, zinc oxide, iron oxide, magnesium oxide, metal borates, such as zinc borate, melamine pyrophosphates, melamine cyanurates, anti-drip agents of a silicone or fluorinated nature. The flame retardant may also be a mixture of the aforementioned agents.

[0061] They may also be halogenated flame retardants such as brominated or polybrominated polystyrene, brominated polycarbonate or brominated phenol.

[0062] The flame retardant agent may also be chosen from the metal salt of phosphinic acid of the following formula (I) and the metal salt of diphosphinic acid of the following formula (II): [Chem 1] r -1 - œ [Chem 2] r -, r (II) II _ n O — P — RJ—P—O my ll R1 H2 Jn with RI and R2, independently of each other, denote a linear or branched C1-C6 alkyl group, or an aryl group; R3 represents a linear or branched C1-C10 alkylene, C6-C10 arylene, C6-C10 alkylarylene, or C6-C10 arylalkylene group, M is an ion of Mg, Ca, Al, Sb, Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, K and / or a protonated amine base m denotes an integer from 1 to 4, n denotes an integer from 1 to 4, x denotes an integer from 1 to 4, n and m being chosen so that the salt is neutral, i.e. it does not carry an electric charge.

[0063] Preferably, M represents a calcium, magnesium, aluminum or zinc ion.

[0064] Preferably, R1 and R2, independently of one another, denote a methyl, ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl, n-pentyl and / or phenyl group.

[0065] Preferably, R3 represents a methylene, ethylene, n-propylene, iso-propylene, n-butylene, tert-butylene, n-pentylene, n-octylene, n-dodecylene group; phenylene, naphthylene; methylphenylene, ethylphenylene, tert-butylphenylene, methylnaphthylene, ethylnaphthylene, tert-butylnaphthylene; phenylmethylene, phenylethylene, phenylpropylene, or phenylbutylene.

[0066] The flame retardant may be the product with the trade name Exolit OP 1230 sold by Clariant, which is the aluminum salt of diethylphosphinic acid salt (CAS No. 225789-38-8).

[0067] More particularly, the content of flame retardant agent is between 0 and 30% by weight, preferably 15 and 25% by weight, and more particularly between 17 and 22% by weight relative to the total weight of the composition.

[0068] SHOCK MODIFIERS

[0069] The composition constituting the envelope of the device according to the invention may comprise at least one impact modifier. Preferably, the composition constituting the envelope of the device according to the invention may comprise from 0 to 20% by weight relative to the total weight of the composition of at least one impact modifier.

[0070] The impact modifier is advantageously constituted by a polymer having a flexural modulus of less than 100 MPa measured according to standard ISO 178 at 50% RH and a Tg of less than 0°C measured according to standard 11357-2 of 2013.

[0071] The glass transition temperature Tg of the polyamides is measured using a differential scanning calorimeter (DSC), after a second heating pass, according to the ISO 1 1357-2:2013 standard. The heating and cooling rate is 20°C / min.

[0072] Preferably, the impact modifier consists of one or more polyolefins, some or all of which carry a function chosen from carboxylic acid, carboxylic anhydride and epoxide functions. In particular, the polyolefin may be chosen from an ethylene and propylene copolymer with an elastomeric character (EPR), an ethylene-propylene-diene copolymer with an elastomeric character (EPDM) and an ethylene / alkyl (meth)acrylate copolymer.

[0073] The composition may comprise up to 20% by weight, relative to the total weight of said composition, of a semi-crystalline polyolefin or a mixture of polyolefins, having a flexural modulus, measured according to standard ISO 178 at 50% RH, greater than 300 MPa, advantageously greater than 800 MPa.

[0074] This impact modifier can be a functionalized polyolefin (Bl).

[0075] According to the invention, functionalized polyolefin (Bl) means the following polymers.

[0076] The functionalized polyolefin (Bl) may be an alpha-olefin polymer having reactive units: the functionalities. Such reactive units are the carboxylic acid, anhydride, or epoxy functions.

[0077] By way of example, polyolefins may be mentioned homopolymers or copolymers of alpha olefins or diolefins, such as, for example, ethylene, propylene, butene-1, octene-1, butadiene, and more particularly: - homopolymers and copolymers of ethylene, in particular LDPE, HDPE, LLDPE (linear low density polyethylene), VLDPE (very low density polyethylene) and metallocene polyethylene, - homopolymers or copolymers of propylene, - ethylene / alpha-olefin copolymers such as ethylene / propylene, EPR (abbreviation for ethylene-propylene-rubber) and ethylene / propylene / diene (EPDM), - styrene / ethylene-butene / styrene (SEBS), styrene / butadiene / styrene (SBS), styrene / isoprene / styrene (SIS), styrene / ethylene-propylene / styrene (SEPS),- copolymers of ethylene with at least one product chosen from salts or esters of unsaturated carboxylic acids such as alkyl (meth)acrylate (for example methyl acrylate), or vinyl esters of saturated carboxylic acids such as vinyl acetate (EVA), the proportion of comonomer being able to reach 40% by weight.

[0078] These polyolefins described above can be grafted, co-polymerized or terpolymerized by reactive units (the functionalities), such as carboxylic acid, anhydride, or epoxy functions.

[0079] More particularly, these polyolefins are grafted or co- or terpolymerized by unsaturated epoxides such as glycidyl (meth)acrylate, or by carboxylic acids or the corresponding salts or esters such as (meth)acrylic acid (the latter being able to be neutralized totally or partially by metals such as Zn, etc.) or even by carboxylic acid anhydrides such as maleic anhydride.

[0080] The functionalized polyolefin (Bl) can be chosen from the following (co)polymers, grafted with maleic anhydride or glycidyl methacrylate, in which the grafting rate is for example from 0.01 to 5% by weight: - PE, PP, copolymers of ethylene with propylene, butene, hexene, or octene containing for example 35 to 80% by weight of ethylene; - ethylene / alpha-olefin copolymers such as ethylene / propylene, EPR (abbreviation for ethylene-propylene-rubber) and ethylene / propylene / diene (EPDM), - styrene / ethylene-butene / styrene (SEBS), styrene / butadiene / styrene (SBS), styrene / isoprene / styrene (SIS), styrene / ethylene-propylene / styrene (SEPS) block copolymers, - ethylene and vinyl acetate (EVA) copolymers, containing up to 40% by weight of vinyl acetate, - ethylene and alkyl (meth)acrylate copolymers, containing up to 40% by weight of alkyl (meth)acrylate, - ethylene vinyl acetate (EVA) and alkyl (meth)acrylate copolymers, containing up to 40% by weight of comonomers.

[0081] A functionalized polyolefin is for example a PE / EPR mixture, the weight ratio of which can vary widely, for example between 40 / 60 and 90 / 10, said mixture being co-grafted with an anhydride, in particular maleic anhydride, according to a grafting rate for example of 0.01 to 5% by weight.

[0082] The functionalized polyolefin (Bl) can also be chosen from ethylene / propylene copolymers with a majority of propylene grafted with maleic anhydride then condensed with mono-amine polyamide (or a polyamide oligomer) (products described in EP-A-0342066).

[0083] The functionalized polyolefin (Bl) can also be a co- or terpolymer of at least the following units: (1) ethylene, (2) alkyl (meth)acrylate or vinyl ester of saturated carboxylic acid and (3) anhydride such as maleic anhydride or (meth)acrylic acid or epoxy such as glycidyl (meth)acrylate.

[0084] As examples of functionalized polyolefins of the latter type, the following copolymers may be mentioned, where ethylene preferably represents at least 60% by weight and where the termonomer (the function) represents, for example, from 0.1 to 12% by weight of the copolymer: - ethylene / alkyl (meth)acrylate / (meth)acrylic acid or maleic anhydride or glycidyl methacrylate copolymers; - ethylene / vinyl acetate / maleic anhydride or glycidyl methacrylate copolymers; - ethylene / vinyl acetate or alkyl (meth)acrylate / (meth)acrylic acid or maleic anhydride or glycidyl methacrylate copolymers.

[0085] In the above copolymers, the (meth)acrylic acid may be salified with Zn or Li. The term "alkyl (meth)acrylate" in (Bl) denotes C1 to C8 alkyl methacrylates and acrylates, and may be chosen from methyl acrylate, acrylate ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, methyl methacrylate and ethyl methacrylate.

[0086] Furthermore, the aforementioned polyolefins (B 1) can also be crosslinked by any suitable process or agent (diepoxy, diacid, peroxide, etc.); the term functionalized polyolefin also includes mixtures of the aforementioned polyolefins with a difunctional reagent such as diacid, dianhydride, diepoxy, etc. capable of reacting with them or mixtures of at least two functionalized polyolefins capable of reacting with each other.

[0087] The above-mentioned copolymers (Bl) can be copolymerized in a random or block manner and have a linear or branched structure.

[0088] The molecular weight, the MFI index, the density of these polyolefins can also vary to a large extent, which a person skilled in the art will appreciate. The MFI index, abbreviation of Melt Flow Index, is the melt flow index. It is measured according to the ASTM 1238 standard.

[0089] Advantageously, the functionalized polyolefins (Bl) are chosen from any polymer comprising alpha olefinic units and units carrying polar reactive functions such as epoxy, carboxylic acid or carboxylic acid anhydride functions. Examples of such polymers that may be mentioned are terpolymers of ethylene, alkyl acrylate and maleic anhydride or glycidyl methacrylate such as the Applicant's Lotader® or polyolefins grafted with maleic anhydride such as the Applicant's Orevac® as well as terpolymers of ethylene, alkyl acrylate and (meth)acrylic acid. Mention may also be made of homopolymers or copolymers of polypropylene grafted with a carboxylic acid anhydride then condensed with polyamides or mono-amino oligomers of polyamide, as described in application EP 0 342 066.

[0090] More particularly, the functionalized polyolefins (Bl) are: - terpolymers of ethylene, alkyl acrylate and maleic anhydride; - terpolymers of ethylene, alkyl acrylate and glycidyl methacrylate; - polypropylene and polyethylenes grafted with maleic anhydride; - copolymers of ethylene and propylene and possibly of diene monomer grafted with maleic anhydride; - copolymers of ethylene and octene grafted with maleic anhydride; and their mixture.

[0091] The functionalized polyolefin (Bl) is present in a content of between 0 and 20% by weight, preferably between 1 and 10% by weight relative to the total weight of the composition.

[0092] Advantageously, the composition according to the invention can comprise at least one non-functionalized polyolefin (B2).

[0093] A non-functionalized polyolefin (B2) is conventionally a homopolymer or copolymer of alpha olefins or diolefins, such as, for example, ethylene, propylene, butene-1, octene-1, butadiene. Examples include: - homopolymers and copolymers of polyethylene, in particular LDPE, HDPE, LLDPE (linear low density polyethylene), VLDPE (very low density polyethylene) and metallocene polyethylene, - homopolymers or copolymers of propylene, - ethylene / alpha-olefin copolymers such as ethylene / propylene, EPR (abbreviation for ethylene-propylene-rubber) and ethylene / propylene / diene (EPDM), - styrene / ethylene-butene / styrene (SEBS), styrene / butadiene / styrene (SBS), styrene / isoprene / styrene (SIS), styrene / ethylene-propylene / styrene (SEPS) block copolymers,- copolymers of ethylene with at least one product chosen from salts or esters of unsaturated carboxylic acids such as alkyl (meth)acrylate (for example methyl acrylate), or vinyl esters of saturated carboxylic acids such as vinyl acetate (EVA), the proportion of comonomer being able to reach 40% by weight and their mixture.

[0094] The above-mentioned copolymers (B2) can be copolymerized in a random or block manner and have a linear or branched structure.

[0095] Advantageously, the non-functionalized polyolefins (B2) are chosen from homopolymers or copolymers of polypropylene and any homopolymer of ethylene or copolymer of ethylene and a comonomer of higher alpha olefin type such as butene, hexene, octene or 4-methyl-1-pentene. Examples that may be mentioned are PP (PolyPropylene), high density polyethylenes, medium density polyethylenes, linear low density polyethylenes, low density polyethylenes, very low density polyethylenes. These polyethylenes are known to those skilled in the art as being produced according to a radical process, according to Ziegler type catalysis or, more recently, according to so-called metallocene catalysis. Also preferred are copolymers of ethylene and vinyl acetate (EVA), such as those marketed under the trade name EVATANE® by the Applicant.

[0096] When the composition constituting the external envelope of the device according to the invention comprises one or more non-functionalized polyolefins, the MFI of (A) and the MFIs of (B1) and (B2) can be chosen from a wide range, it is however recommended to facilitate the dispersion of (B1) and (B2) that the viscosities of (B1) and (B2) be close.

[0097] The non-functionalized polyolefin is present in a content of between 0 and 20% by weight, preferably between 1 and 10% by weight relative to the total weight of the composition.

[0098] The impact modifier may also be a copolymer formed from polyamide blocks and polyether blocks, the polyamide blocks and the polyether blocks being linked by an ester function. These products are described in document FR 2 273 021 and sold under the trade name PEBAX® by the company ARKEMA.

[0099] Polyamide block copolymers (abbreviated below as PA) and polyether block copolymers (abbreviated below as PE) result from the copolycondensation of polyamide blocks with reactive ends with polyether blocks with reactive ends. For example, it is possible to react: - polyether diol, and a polyamide dicarboxylic acid, - polyether diamine and a polyamide dicarboxylic acid, - polyether diol and a polyamide diamine.

[0100] The polyamide blocks with dicarboxylic chain ends originate, for example, from the condensation of polyamide precursors in the presence of a chain-regulating dicarboxylic acid. The polyamide blocks with diamine chain ends originate, for example, from the condensation of polyamide precursors in the presence of a chain-regulating diamine. Thus, the bond between the blocks is either an ester bond or an amide bond. The polymers with PA blocks and PE blocks may comprise a single PA block and a single PE block.

[0101] They can also comprise several PA blocks identical in terms of structure of the monomer(s) constituting the polyamide and identical PE distributed randomly. Said polymers can be prepared by simultaneous reaction of the PE blocks and the precursors of the PA blocks. A polymer is then obtained having PE blocks and PA blocks of very variable length depending on the moment at which the chain regulator intervenes during the formation of the PA block, but also the different reagents having reacted randomly which are distributed randomly (statistically) along the polymer chain.

[0102] The composition constituting the external envelope of the device according to the invention comprises from 0 to 30% by weight relative to the total weight of the composition of at least one impact modifier, preferably from 0.1 to 25%, and more preferably from 5 to 20%.

[0103] ADDITIVES

[0104] The composition constituting the external envelope of the device according to the invention may also comprise from 0 to 20% of additives.

[0105] Preferably, the additives present in the composition constituting the envelope are chosen from thermal 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.

[0106] Among the fillers, we can notably cite silica, titanium oxide or even glass beads.

[0107] The thermal stabilizer may be chosen from a copper-based stabilizer, an organic stabilizer and a mixture thereof.

[0108] The copper-based stabilizer may consist of one or more constituents selected from copper-based compounds such as cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, cuprous iodide, cupric iodide, cuprous acetate and cupric acetate. Halides and acetates of other metals such as silver may be mentioned. These copper-based compounds are typically combined with alkali metal halides. A well-known example is the mixture of CuI and KI, where the CuIK1 ratio is typically between 1:5 and 1:15. An example of such a stabilizer is Polyadd P201 from Ciba. Further details on copper-based stabilizers can be found in US Patent 2,705,227. More recently, copper-based stabilizers have appeared, such as complexed coppers such as Bruggolen H3336, H3337, H3373 from the Brueggemann company.The copper-based stabilizer is selected from copper halides, copper acetate, copper halides or copper acetate in admixture with at least one alkali metal halide, and mixtures thereof, preferably mixtures of copper iodide and potassium iodide (CuEKI).

[0109] The organic stabilizer can be chosen, without this list being restrictive, from: - phenolic antioxidants, for example Irganox 245, Irganox 1010, Irganox 1098 from the company Ciba, Irganox MD 1024 from the company Ciba, Lowinox 44B25 from the company Great Lakes, - phosphorus-based stabilizers, such as phosphites, for example Irgafos 168 from Ciba, - a UV absorber, such as Tinuvin 312 from Ciba, - a HALS, as previously mentioned, - an amine-type stabilizer, such as Naugard 445 from Crompton, or a hindered amine-type stabilizer such as Tinuvin 770 from Ciba, - a multifunctional stabilizer such as Nylostab S-EED from Clariant.

[0110] It is obviously possible to envisage a mixture of two or more of these organic stabilizers.

[0111] The amount of thermal stabilizer(s) within the composition is preferably between 0.05 and 5% by weight, relative to the total weight of the composition.

[0112] Preferably, the additives are present in the composition generally in a content of 0.1 to 15% by weight, preferably 1 to 15% by weight relative to the total weight of the composition.

[0113] Depending on the position of the battery in the vehicle, the person skilled in the art will be able to adapt the content of reinforcing fiber, impact modifier or additive. If the battery is positioned at the level of the luggage compartment, its external compartment will be less exposed to an aggressive external environment. The content of reinforcing fiber and impact modifier may be in the lower range of the claimed range. On the other hand, if the battery is in contact with the ambient air, then the content of reinforcing fibers and impact modifier will be higher, and the composition must include additives, such as antioxidants or UV filters.

[0114] According to a preferred embodiment of the invention, the external envelope is made up of a composition consisting of: - from 20 to 65% by weight relative to the total weight of the composition of reinforcing fibers, which do not have thermal conduction properties, - from 0.1 to 30% by weight relative to the total weight of at least one impact modifier, - from 0 to 30% a flame retardant agent; - from 0 to 20% by weight relative to the total weight of the additive composition, - the complement being a matrix comprising mainly at least one polyamide.

[0115] According to another preferred embodiment of the invention, the outer envelope is made of a composition comprising - from 20 to 65% by weight relative to the total weight of the composition of reinforcing fibers, which do not have thermal conduction properties; - from 0.1 to 30% by weight relative to the total weight of at least one impact modifier, - 15 to 25% flame retardant - from 0 to 20% by weight relative to the total weight of the additive composition, - the complement being a matrix comprising mainly at least one polyamide.

[0116] According to another preferred embodiment of the invention, the outer envelope is made of a composition comprising - from 40 to 65% by weight relative to the total weight of the composition of reinforcing fibers, which do not have thermal conduction properties, - from 5 to 20% by weight relative to the total weight of at least one impact modifier, - 15 to 25% flame retardant; - from 1 to 20% by weight relative to the total weight of the additive composition, - the complement being a matrix comprising mainly at least one polyamide.

[0117] According to another preferred embodiment of the invention, the outer envelope is made of a composition consisting of - from 40 to 65% by weight relative to the total weight of the composition of reinforcing fibers, which do not have thermal conduction properties, - from 5 to 20% by weight relative to the total weight of at least one impact modifier, - from 15 to 25% a flame retardant; - from 1 to 20% by weight relative to the total weight of the additive composition, - the complement being a matrix comprising mainly at least one polyamide.

[0118] INNER ENVELOPE

[0119] The internal envelope arranged opposite the battery and intended to be in contact with a heat transfer fluid is made up of a composition comprising: - from 5 to 65% by weight relative to the total weight of the composition of reinforcing fibers, - from 10 to 20% by weight relative to the total weight of at least one thermally conductive component, when the reinforcing fibers used are not thermally conductive, - at least one flame retardant, and -the complement being a matrix comprising mainly at least one polyamide chosen from semi-aromatic 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.

[0120] POLYAMIDES

[0121] Like the polyamides defined above for the outer shell, the polyamides suitable for the inner shell may be homopolyamides or copolyamides.

[0122] The lactams and amino acids used to obtain homopolyamides must have an average number of carbon atoms per nitrogen atom of between 7 and 10. Advantageously, the lactams and amino acids are CIO.

[0123] The monomers useful for obtaining the polyamide(s) present in the matrix of the composition constituting the internal envelope are chosen from the lists of polyamides of the external layer.

[0124] According to a preferred embodiment, the polyamide of the inner layer is chosen from PA610, PA410, PA412, PA612, PA1010, PA6T, PA6I, PA9T, PA10T, PA6T / 6I, PA6T / 10T, PA6T / 1010, PA10T / 1010, and their mixture. Preferably, the polyamide constituting the matrix of the inner envelope is chosen from PA 610, PA612, PA9T, PA10T, and PA 1010.

[0125] REINFORCING FIBER

[0126] The reinforcing fibers present in the composition constituting the internal envelope are identical to those listed above for the external envelope.

[0127] CONDUCTIVE COMPONENTS

[0128] The composition constituting the internal envelope of the device according to the invention comprises from 10 to 20% by weight relative to the total weight of the composition of at least one thermally conductive component, preferably from 12 to 18%.

[0129] The thermally conductive components make it possible to confer thermal conductivity on the polymer matrix, which accommodates them, or to increase its thermal conductivity.

[0130] The thermally conductive components may be chosen from carbon, carbon fibers, carbon black such as that sold by the company Imerys under the name Ensaco 250G, carbon nanotubes (denoted NTC) such as those sold by Arkema in the form of MB Graphistrength#, expanded graphite such as the Timrex®C-THERM™ range, and in particular the product with the trade name Timrex®C-THERM™ 001 sold by the company Imerys, aluminum nitride and boron nitride.

[0131] It is possible that the selected reinforcing fibers have thermal conduction properties, such as for example carbon fibers, CNTs, carbon nanofibers or graphenes. In this eventuality, the composition may not include a thermally conductive component.

[0132] FIRE RETARDANTS

[0133] The flame retardants present in the composition constituting the inner envelope are identical to those listed above for the outer envelope.

[0134] SHOCK MODIFIERS

[0135] The impact modifiers present in the composition constituting the internal envelope are identical to those listed above for the external envelope.

[0136] ADDITIVES

[0137] The additives present in the composition constituting the internal envelope are identical to those listed above for the external envelope.

[0138] According to a preferred embodiment of the invention, the internal envelope is made up of a composition comprising: - from 5 to 65% by weight relative to the total weight of the reinforcing fiber composition, - from 10 to 20% by weight relative to the total weight of at least one thermally conductive component, when the reinforcing fibers used are not thermally conductive, - 15 to 25% flame retardant; - from 0 to 30% by weight relative to the total weight of at least one impact modifier, - from 0 to 20% by weight relative to the total weight of the additive composition, - the complement being a matrix comprising mainly at least one polyamide.

[0139] According to a preferred embodiment of the invention, the internal envelope is made up of a composition comprising: - from 5 to 65% by weight relative to the total weight of the reinforcing fiber composition, - from 10 to 20% by weight relative to the total weight of at least one thermally conductive component, when the reinforcing fibers used are not thermally conductive, - 15 to 25% flame retardant; - from 5 to 20% by weight relative to the total weight of at least one impact modifier, - from 1 to 20% by weight relative to the total weight of the additive composition, - the complement being a matrix comprising mainly at least one polyamide.

[0140] According to a preferred embodiment of the invention, the internal envelope is made up of a composition consisting of: - from 5 to 65% by weight relative to the total weight of the reinforcing fiber composition, - from 10 to 20% by weight relative to the total weight of at least one thermally conductive component, when the reinforcing fibers used are not thermally conductive, - 15 to 25% flame retardant; - from 5 to 20% by weight relative to the total weight of at least one impact modifier, - from 1 to 20% by weight relative to the total weight of the additive composition, - the complement being a matrix comprising mainly at least one polyamide.

[0141] According to another preferred embodiment of the invention, the internal envelope is made up of a composition comprising: - from 5 to 65% by weight relative to the total weight of the composition of reinforcing fibers, which have thermal conduction properties, - 15 to 25% flame retardant; - from 0 to 30% by weight relative to the total weight of at least one impact modifier, - from 0 to 20% by weight relative to the total weight of the additive composition, - the complement being a matrix comprising mainly at least one polyamide.

[0142] According to another preferred embodiment of the invention, the internal envelope is made up of a composition comprising: - from 5 to 65% by weight relative to the total weight of the composition of reinforcing fibers, which have thermal conduction properties, - 15 to 25% flame retardant; - from 5 to 20% by weight relative to the total weight of at least one impact modifier, - from 1 to 20% by weight relative to the total weight of the additive composition, - the complement being a matrix comprising mainly at least one polyamide.

[0143] According to another preferred embodiment of the invention, the internal envelope is made up of a composition comprising: - from 5 to 65% by weight relative to the total weight of the composition of reinforcing fibers, which have thermal conduction properties, - 15 to 25% flame retardant; - from 5 to 20% by weight relative to the total weight of at least one impact modifier, - from 1 to 20% by weight relative to the total weight of the additive composition, - the complement being a matrix comprising mainly at least one polyamide.

[0144] According to another preferred embodiment of the invention, the internal envelope is made up of a composition consisting of: - from 5 to 65% by weight relative to the total weight of the composition of reinforcing fibers, which have thermal conduction properties, - 15 to 25% flame retardant; - from 5 to 20% by weight relative to the total weight of at least one impact modifier, - from 1 to 20% by weight relative to the total weight of the additive composition, - the complement being a matrix comprising mainly at least one polyamide.

[0145] Advantageously, when the battery comprises a plurality of adjacent cell packs, then the internal envelope encapsulates all of the cells by shape complementarity.

[0146] According to another characteristic, the internal envelope and / or the external envelope may be coated internally and / or externally with a layer having low permeability to water.

[0147] The presence of one or more layers having low permeability to water makes it possible to provide a moisture barrier effect, i.e. to ensure the sealing of the battery with respect to, depending on its location, the heat transfer fluid or the external environment of the device according to the invention.

[0148] For the purposes of the present invention, internal means a layer arranged opposite the passage of the heat transfer fluid.

[0149] By external, we mean in the sense of the present invention a layer arranged facing the exterior of the device according to the invention or facing the battery, unlike a layer arranged facing the passage of the heat transfer fluid.

[0150] In particular, according to an embodiment in which the heat transfer fluid chosen is liquid, for example fluorinated compounds, the layer(s) having low permeability to water makes it possible to avoid, depending on its / their location, leaks of the fluid towards the battery or towards the outside of the cooling and / or heating device.

[0151] According to a preferred embodiment, this / these layer(s) may be made of EVOH, polyolefins, such as polypropylene or polyethylenes: HDPE, LDPE.

[0152] CONDUCTIVITY MEASUREMENT

[0153] Preferably, the ratio of the thermal conductivity (X) of the inner envelope to the thermal conductivity (X) of the outer envelope is at least greater than 1.5, preferably ranging from 1.5 to 300, more particularly from 2 to 100, and more preferably from 2 to 50.

[0154] Preferably, the thermal conductivity (X) of the external envelope is less than or equal to 10 Wm *.K ', preferably between 0.1 and 10 Wm *.K ', more particularly between 0.3 and 1 Wm *.K '.

[0155] Thermal conductivity measurements of materials are carried out using HOT DISK technology as detailed in the ISO 22007-2 standard.

[0156] The convection coefficient can also be used to qualify the heat transfer between an envelope and the fluid circulating in the device. In the device according to the invention, the external envelope does not allow or allows little heat transfer between the fluid and the material of the envelope. "On the other hand, the material of the internal envelope is chosen so as to allow maximum heat transfer between the internal envelope close to or in contact with the battery and the fluid.

[0157] PROCESS FOR PREPARING THE COMPOSITION

[0158] The invention also relates to a process for preparing the composition as defined above. According to this process, the composition can be prepared by any method which makes it possible to obtain a homogeneous mixture containing the composition according to the invention, and optionally other additives, such as extrusion in the melt state, compacting, or even roller mixing, while taking into account the size of the reinforcing fibers.

[0159] Advantageously, the usual mixing and kneading devices of the thermoplastics industry are used, such as extruders, such as twin-screw extruders, and kneaders, for example BUSS co-kneaders.

[0160] METHOD FOR MANUFACTURING THE DEVICE

[0161] Depending on the size of the fibers, the battery device according to the invention can be produced by different techniques.

[0162] When the fibers are short, the battery device according to the invention can be obtained by injection, extrusion, coextrusion, hot compression, multi-injection from at least one composition as defined above.

[0163] When the fibers are long or continuous, the battery device according to the invention can be made by different techniques chosen from: pultrusion, filament winding, thermocompression, infusion molding, resin transfer molding (RTM), structured reaction injection molding (S-RIM) or injection-compression molding. A particular closed-mold technique is RTM or S-RIM or injection-compression. The term "resin" in RTM is identified here with the composition according to the invention without the reinforcing fibers.

[0164] According to a particular embodiment, the manufacturing method may comprise - a step of applying the reinforcing fibers in the mold, then - at least one step of impregnating said fibers with a precursor composition of the composition according to the invention.

[0165] THE CIRCUIT

[0166] The present invention also relates to a cooling and / or heating circuit for an electric or hybrid motor vehicle battery, comprising a main loop for circulating a heat transfer fluid provided with means intended for circulating the heat transfer fluid in the main loop.

[0167] Furthermore, the main loop is connected to a reversible heat pump and to a cooling and / or heating device as previously described.

[0168] According to different embodiments, the heat transfer fluid is chosen from a gas, for example air, a liquid, for example glycolated water, hydrocarbon compounds, hydrofluorocarbons, ethers, hydrofluoroethers, CO2, NH3, SO2 and fluoroolefins.

[0169] Preferably, the refrigerant fluid is chosen from hydrocarbon, hydrofluorocarbon, ether, hydrofluoroether, halocarbon, CO2, NH3, SO2 and fluoroolefin compounds.

[0170] In one embodiment, the heat transfer fluid is a refrigerant selected from CO2, haloalkanes, haloalkenes, fluoropropenes, fluoropropanes and fluoroethanes; preferably from 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, l-chloro-3,3,3-trifluoropropene, 1- chloro-2,3,3,3-tetrafluoropropene, l-chloro-2,3,3,3-tetrafluoropropene, and mixtures comprising these.

[0171] In the context of the invention, "HFO-1234yf" refers to 2,3,3,3-tetrafluoropropene, "HCFO-1233zd" refers to l-chloro-3,3,3-trifluoropropene, "HCFO-1224yd" refers to l-chloro-2,3,3,3-tetrafluoropropene, and "HFO-1336mzz" refers to l,l,l,4,4,4-hexafluorobut-2-ene.

[0172] In a preferred embodiment, the heat transfer fluid is a refrigerant chosen from 1,3,3,3-tetrafluoropropene (1234ze), 2,3,3,3-tetrafluoropropene (HFO-1234yf or 1234yf), difluoromethane (HFC-32); in particular the heat transfer fluid is 2,3,3,3-tetrafluoropropene (1234yf) and difluoromethane, alone or as a mixture.

[0173] The heat transfer fluid may be a mixture of 2,3,3,3-tetrafluoropropene (HFO-1234yf) and difluoromethane (HFC-32) in proportions ranging from 20 to 95% by weight of HFO-1234yf relative to the total weight of the mixture, the balance to 100% being HFC-32. The transfer fluid may be one of the following mixtures HFO-1234yf / HFC-32 of 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 in percentage by weight relative to the total weight of the mixture.

[0174] Advantageously, the refrigerant fluid contains a lubricant, preferably chosen from mineral oils, silicone oils, paraffins of natural origin, naphthenes, synthetic paraffins, alkylbenzenes, poly-alpha olefins, polyalkylene glycols, polyol esters and / or polyvinyl ethers; the lubricant being more particularly preferably a polyalkylene glycol or a polyol ester.

[0175] According to a characteristic of the invention, the circuit may comprise at least one secondary loop connected to the main loop, the secondary loop(s) being connected to the passenger compartment of the motor vehicle and / or to an electronic circuit connected to an electric motor of the motor vehicle and / or to an internal combustion engine of the motor vehicle, when the motor vehicle is of the hybrid type.

[0176] Advantageously, the circuit may comprise a control device configured to control the heat transfer from the main loop to the at least one secondary loop as defined previously.

[0177] Other aims, advantages and characteristics will emerge from the description which follows, given by way of purely illustrative example and made with reference to the appended drawings in which:

[0178] [Fig. 1] is a sectional view of a device for cooling and / or heating a battery for an electric or hybrid motor vehicle, the device comprising an internal envelope and an external envelope.

[0179] [Fig.2] is a sectional view of a portion of a cooling device and / or heating of a battery for an electric or hybrid motor vehicle, the device comprising internal and external envelopes, [Fig.2] illustrating a configuration of the external envelope alternative to the external envelope illustrated in [Fig. 1].

[0180] Figures 1 and 2 illustrate two embodiments of a device for cooling and / or heating an electric or hybrid vehicle battery according to the invention.

[0181] In [Fig.l], the cooling and / or heating device according to the invention 1 illustrated comprises two casings. An inner casing 2 is arranged opposite the battery 3. An outer casing 4 forms with the inner casing 2 a passage intended for the flow of the 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.

[0182] In the example illustrated, a space 8 is provided between the battery 3 and the internal casing 2. According to an alternative, it may be provided that the internal casing 2 is arranged, at least in part, in contact with the battery so as to optimize the heat transfer between the battery 3 and the heat transfer fluid 5.

[0183] Conventionally, the battery 3 comprises a plurality of adjacent cell packs. According to another example illustrated in [Fig.2], the internal envelope 2 is inserted between two adjacent cell packs. [Fig.2] schematically represents a portion of the battery 3 comprising three identical cell packs 9, 10 and 11. Reference will be made to the adjacent packs 9 and 10 each comprising four walls, respectively 9a, 9b, 9c, 9d and 10a, 10b, 10c, 10d. In the example illustrated, the internal envelope 2 is arranged partly opposite the walls 9a, 9b, 9c, 9d of the pack 9 and the walls 10a, 10b, 10c, 10d of the pack 10.

[0184] The internal envelope 2 thus extends as close as possible to the cell packs of the battery 3 so as to match their shape, thus making it possible to improve the heat transfer between the battery 3 and the heat transfer fluid 5 for better energy recovery. The polyamide composition advantageously makes it possible to easily and quickly manufacture such an envelope 2 adapted to the complex geometry of the battery 3.

[0185] Advantageously, the internal and external envelopes may be coated with a layer having low water permeability. The layer(s) (not shown in the figures) may be internal or external.

[0186] Preferably, at least one layer having low water permeability is arranged in contact with the internal envelope 2, internally, that is to say in contact with the heat transfer fluid 5.

[0187] The heat transfer fluid 5 has the function of transferring heat between two or more temperature sources. This fluid can be a gas, air or a liquid.

[0188] [Fig. 3] illustrates a circuit according to a particular embodiment of the invention. The circuit 20 comprises a device according to the invention 21 encapsulating a battery, an expansion valve 22, a heat exchanger 23, a four-way valve 24, and a compressor 25. The heat exchanger 23 is of the air / heat transfer fluid type, preferably refrigerant fluid. The heat exchanger 23 is crossed by the refrigerant fluid of the circuit 20 and by the air flow supplied by a fan. Part or all of this same air flow can, for example, cross a heat exchanger of the cooling circuit of a heat engine for a hybrid vehicle (not shown in the figure) or the passenger compartment. The direction of air circulation depends on the operating mode of the circuit 20, the needs of the battery and the needs of the heat engine, for hybrid vehicles.

[0189] In refrigeration mode, that is to say when the battery generates heat, the refrigerant set in motion by the compressor 25 passes, via the valve 24, then the device 21 acting as a condenser (that is to say it releases calories to the outside), then the expansion valve 22, then the exchanger 23 acting as an evaporator, thus allowing the cooling of the air flow intended to be pulsed inside the passenger compartment of the motor vehicle.

[0190] In heat pump mode, that is to say when the battery needs to be heated, during start-up for example, the direction of flow of the refrigerant is reversed via the valve 24. The heat exchanger 23 acts as a condenser, while the device 21 acts as an evaporator. The heat exchanger 23 then makes it possible to heat the air flow intended for the passenger compartment of the motor vehicle.

[0191] The exchangers of the cooling circuit can be activated using the valves according to the needs of the thermal engine (heating of the air entering the engine or recovery of energy produced by this engine).

[0192] Furthermore, the vapor compression circuit may comprise different branches equipped with separate heat exchangers, the refrigerant circulating or not in these branches, depending on the operating mode. Optionally, alternatively or in addition, the vapor compression circuit may comprise means for changing the direction of circulation of the refrigerant, comprising for example one or more three-way or four-way valves.

[0193] [Fig.4] illustrates a circuit according to another embodiment of the invention. The circuit 30 comprises two heat transfer fluid circulation loops 32 and 36, a loop 32 in which air circulates and a loop 36 in which a refrigerant circulates. Loop 32 comprises a device according to the invention 31 encapsulating a battery and a heat exchanger 33 of the air / fluid type. This loop 32 comprises an air flow making it possible to heat or cool the battery. A fan can be incorporated in this loop in order to circulate the air. Heat exchanger 33 is also part of loop 36, which comprises a compressor 34, a heat exchanger 35 and an expansion valve 37. Exchanger 35 can be connected to the passenger compartment of the vehicle or to the heat engine for the particular case of a hybrid vehicle.

Claims

Claims

1. Device intended to be used in a cooling and / or heating circuit of an electric or hybrid motor vehicle battery, comprising: - an outer casing consisting of a composition comprising: — from 20 to 65% by weight relative to the total weight of the composition of reinforcing fibers, which do not have thermal conduction properties — the remainder being a matrix comprising predominantly at least one polyamide and - an inner casing arranged opposite the battery and intended to be in contact with a refrigerant fluid consisting of a composition comprising: — from 5 to 65% by weight relative to the total weight of the composition of reinforcing fibers, — from 10 to 20% by weight relative to the total weight of at least one thermally conductive component, when the reinforcing fibers used are not thermally conductive, — at least one flame retardant,and — the complement being a matrix comprising mainly at least one polyamide chosen from semi-aromatic 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 - a heat transfer fluid inlet; and - a heat transfer fluid outlet, the device delimiting a cooling and / or heating volume of the battery.,

2. Device according to claim 1, characterized in that the external envelope comprises a polyamide matrix comprising at least one polyamide chosen from semi-aromatic polyamides and polyamides consisting of units having an average number of carbon atoms per nitrogen atom ranging from 9 to 18.

3. Device according to claim 1 or claim 2, characterized in that the external envelope comprises a polyamide matrix comprising at least one polyamide chosen from PA612, PA 1010, PA10T, PA10T / 1010, PAU, PA12, PA11 / 10T, PA12 / 10T, PA 1012, PA 618, PA 12T, PA 1010 / 1012, PA BACT / 6T, PA BACT / 10T, PA BACT / 12T, PA MPMDT / 6T, PA MPMDT / 10T, PA MPMDT / 12T, PA MXDT / 6T, PA MXDT / 10T, PA MXDT / 12T, PA11 / BACT / 6T, PA 11 / BACT / 10T, PA 11 / BACT / 12T, PA 11 / MPMDT / 6T, PA 11 / MPMDT / 10T, PA 11 / MPMDT / 12T, PA 11 / MXDT / 6T, PA 11 / MXDT / 10T, PA 1 l / MXDT / 12T, and their mixture, preferably chosen from PA12, PA 11, PA 10.10, PA 10.12 and the PA11 / 10.T.

4. Device according to any one of the preceding claims, characterized in that the internal envelope comprises a polyamide matrix comprising at least one polyamide chosen from PA610, PA410, PA412, PA612, PA1010, PA6T, PA6I, PA9T, PA10T, PA6T / 6I, PA6T / 10T, PA6T / 1010, PA10T / 1010, and their mixture.

5. Device according to any one of the preceding claims, characterized in that the reinforcing fibers not having thermal conduction properties present in the composition constituting the external envelope are chosen from glass fibers, basalt fibers, aramid fibers.

6. Device according to any one of the preceding claims, characterized in that the reinforcing fibers having thermal conduction properties present in the composition constituting the internal envelope are chosen from carbon, carbon fibers, carbon black, carbon nanotubes, expanded graphite, aluminum nitride and boron nitride.

7. Device according to any one of the preceding claims, characterized in that the ratio of the thermal conductivity (X) of the internal envelope to the thermal conductivity (X) of the external envelope is at least greater than 1.5

8. Device according to any one of the preceding claims, characterized in that the flame retardant present in the compositions constituting the internal and external envelopes is chosen from a metal salt chosen from a metal salt of phosphinic acid, a metal salt of diphosphinic acid, a polymer containing at least one metal salt of phosphinic acid, a polymer containing at least one metal salt of diphosphinic acid, red phosphorus, an antimony oxide, a zinc oxide, an iron oxide, a magnesium oxide, metal borates, such as zinc borate, melamine pyrophosphates, melamine cyanurates, silicone or fluorinated anti-drip agents, and mixtures thereof.

9. Device according to any one of the preceding claims, characterized in that when the battery (2) comprises a plurality of adjacent cell packs (10, 11, 12), then the internal envelope (8) encapsulates all of the cells by shape complementarity.

10. Device according to any one of the preceding claims, characterized in that the inner casing (8) and / or the outer casing (7) is (are) coated internally and / or externally with a layer having low permeability to water.

11. Use of the device as defined in any one of claims 1 to 10, for cooling and / or heating a battery of an electric or hybrid motor vehicle with a refrigerant fluid chosen from hydrocarbon compounds, hydrofluorocarbons, ethers, hydrofluoroethers, halocarbons, CO2, NH3, SO2 and fluoroolefins.

12. Use according to claim 11, characterized in that the refrigerant fluid is chosen from CO2, halogenoalkanes, halogenoalkenes, fluoropropenes, fluoropropanes and fluoroethanes; preferably from 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, l-chloro-3,3,3-trifluoropropene, l-chloro-2,3,3,3-tetrafluoropropene, 1-chloro-2,3,3,3-tetrafluoropropene, and mixtures thereof.

13. Use according to claim 12, characterized in that the heat transfer fluid is a refrigerant chosen from 1,3,3,3-tetrafluoropropene (1234ze), 2,3,3,3-tetrafluoropropene (1234yf), difluoromethane, l-chloro-3,3,3-trifluoropropene (HCFO-1233zd), l-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd), 1,1,1,4,4,4-hexafluorobut-2-ene (HFO-1336mzz), in particular the heat transfer fluid is 2,3,3,3-tetrafluoropropene (1234yf), or difluoromethane, alone or in mixtures.

14. Use according to any one of claims 11 to 13, characterized in that the refrigerant fluid contains a lubricant, preferably chosen from mineral oils, silicone oils, paraffins of natural origin, naphthenes, synthetic paraffins, alkylbenzenes, poly-alpha olefins, polyalkylene glycols, polyol esters and / or polyvinyl ethers; the lubricant being more particularly preferably a polyalkylene glycol or a polyol ester.

15. Cooling and / or heating circuit for an electric or hybrid motor vehicle battery, comprising a main loop for circulating a heat transfer fluid provided with means for circulating the heat transfer fluid in the main loop, characterized in that the main loop is connected to a reversible heat pump and to a cooling and / or heating device as defined in any one of claims 1 to 10.

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