WO2024256441A1 - Battery pack comprising a heat-transfer fluid capable of containing the thermal runaway of the electrochemical accumulators of the battery pack - Google Patents

Battery pack comprising a heat-transfer fluid capable of containing the thermal runaway of the electrochemical accumulators of the battery pack Download PDF

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Publication number
WO2024256441A1
WO2024256441A1 PCT/EP2024/066181 EP2024066181W WO2024256441A1 WO 2024256441 A1 WO2024256441 A1 WO 2024256441A1 EP 2024066181 W EP2024066181 W EP 2024066181W WO 2024256441 A1 WO2024256441 A1 WO 2024256441A1
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WIPO (PCT)
Prior art keywords
accumulator
transfer fluid
heat transfer
housing
overpressure
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Ceased
Application number
PCT/EP2024/066181
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French (fr)
Inventor
Marc Pontrucher
Jean-François NICOLINO
Joel Devautour
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Safran Electrical & Power Sas
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Safran Electrical & Power Sas
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Filing date
Publication date
Application filed by Safran Electrical & Power Sas filed Critical Safran Electrical & Power Sas
Priority to EP24732906.3A priority Critical patent/EP4728584A1/en
Priority to CN202480039425.5A priority patent/CN121548892A/en
Publication of WO2024256441A1 publication Critical patent/WO2024256441A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/61—Types of temperature control
    • H01M10/613—Cooling or keeping cold
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/65—Means for temperature control structurally associated with the cells
    • H01M10/656—Means for temperature control structurally associated with the cells characterised by the type of heat-exchange fluid
    • H01M10/6567—Liquids
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/65—Means for temperature control structurally associated with the cells
    • H01M10/656—Means for temperature control structurally associated with the cells characterised by the type of heat-exchange fluid
    • H01M10/6569—Fluids undergoing a liquid-gas phase change or transition, e.g. evaporation or condensation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/317—Re-sealable arrangements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/317—Re-sealable arrangements
    • H01M50/325—Re-sealable arrangements comprising deformable valve members, e.g. elastic or flexible valve members
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/342—Non-re-sealable arrangements
    • H01M50/3425—Non-re-sealable arrangements in the form of rupturable membranes or weakened parts, e.g. pierced with the aid of a sharp member
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/35—Gas exhaust passages comprising elongated, tortuous or labyrinth-shaped exhaust passages
    • H01M50/358—External gas exhaust passages located on the battery cover or case
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/62—Heating or cooling; Temperature control specially adapted for specific applications
    • H01M10/625—Vehicles
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/62—Heating or cooling; Temperature control specially adapted for specific applications
    • H01M10/627—Stationary installations, e.g. power plant buffering or backup power supplies
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/64—Heating or cooling; Temperature control characterised by the shape of the cells
    • H01M10/643—Cylindrical cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/64—Heating or cooling; Temperature control characterised by the shape of the cells
    • H01M10/647—Prismatic or flat cells, e.g. pouch cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2200/00—Safety devices for primary or secondary batteries
    • H01M2200/20—Pressure-sensitive devices
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00—Batteries for particular applications
    • H01M2220/10—Batteries in stationary systems, e.g. emergency power source in plant
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00—Batteries for particular applications
    • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • Battery pack comprising a heat transfer fluid capable of containing the thermal runaway of the electrochemical accumulators of the battery pack
  • the invention relates to the field of batteries comprising electrochemical accumulators, in particular accumulators with liquid and/or gel electrolyte. They are composed of two electrodes (cathode and anode) separated by an insulating membrane (or separator) and the whole immersed in a liquid or gel electrolyte.
  • the chemical compounds used are multiple to obtain high capacity accumulators.
  • the most commonly used compound currently is associated with the family of technology called Lithium-Ion, and subfamilies exist using other associations of chemical materials such as Lithium Iron Phosphate (LFP), Lithium-Cobalt-Oxide (LCO), Lithium Nickel Cobalt Aluminum (NCA) and Lithium Nickel Manganese Cobalt (NMC).
  • LFP Lithium Iron Phosphate
  • LCO Lithium-Cobalt-Oxide
  • NCA Lithium Nickel Cobalt Aluminum
  • NMC Lithium Nickel Manganese Cobalt
  • Another family is emerging to overcome the problem of lithium supply, this is Sodium-Ion technology.
  • These accumulators have high energy capacities to meet the needs of the applications.
  • a high energy capacity is particularly useful in the field of transport.
  • These accumulators are assembled in battery packs to integrate into propulsion systems, which are called all-electric when the battery (or battery pack) is the sole source of energy or called hybridized when the battery pack shares the energy supply with another source of energy.
  • These accumulators are also used to constitute high-capacity battery packs to meet a need for so-called stationary energy storage such as the storage of renewable energies on electrical networks.
  • the fields of application are vast and are not limited to the field of land and aeronautical transport, and electrical networks. Also, the application of the present invention concerns all fields that can use high-capacity electrochemical accumulators subject to thermal runaway in the event of abusive use.
  • thermal runaway may be linked to internal alterations of the accumulator (degradation of the accumulator materials generating a short- internal circuit, such as a perforation of a separator by the appearance of dendrites).
  • Figure 1 schematically illustrates a perforation P of a separator S of an accumulator between an anode A and a cathode C.
  • Thermal runaway can also be linked to abusive external environmental conditions (temperature, vibrations, shocks) and/or functional conditions during the charging or discharging of the accumulators.
  • an electrochemical accumulator when hot, an electrochemical accumulator must operate within a defined temperature range, generally less than 70°C at its external surface. Beyond the defined temperature range, damage to the materials constituting the accumulator occurs and is the cause of thermal runaway in the accumulator. Thermal runaway continues in the accumulator when the energy released by the exothermic reactions occurring inside the accumulator exceeds the capacity to dissipate it to the outside and when the defective accumulator cannot be isolated to cool it.
  • thermal runaway can start in one accumulator and spread to one or more neighboring accumulators, or even to the entire battery.
  • the invention aims to improve this solution not only by cooling the accumulators but above all by limiting, in the event of thermal runaway starting in an accumulator, the thermal runaway to the accumulator concerned only.
  • the invention proposes for this purpose a battery comprising: at least one electrochemical accumulator comprising an active part and an envelope enclosing said active part; a housing housing said at least one accumulator; and a heat transfer fluid contained in the housing, the envelope comprising a weakened zone configured to open under the effect of an overpressure in the accumulator and to evacuate gases produced by the active part of the accumulator causing the overpressure.
  • the heat transfer fluid in contact with the gases produced by the accumulator changes from a liquid state to a gaseous state.
  • the solution provided by the invention thus makes it possible to contain the start of a thermal runaway causing excess pressure in the defective accumulator by directly containing the gases produced by the accumulator. Opening the weakened zone of the casing of the defective accumulator allows the fluid to quickly access the gases produced by the accumulator, and thus to circumscribe the thermal runaway as close as possible to its origin and prevent its progression to the heart of the accumulator.
  • the invention reduces the risk of thermal runaway spreading to adjacent cells by directly and rapidly cooling the defective accumulator.
  • the heat transfer fluid enters through the open weakened zone so as to contain at least part of the gases produced by the accumulator.
  • the heat transfer fluid comes into contact, outside the accumulator, with at least part of the evacuated gases.
  • the heat transfer fluid has a liquid/gaseous state change temperature higher than a skin temperature during thermal runaway causing the opening of the weakened zone of said at least one electrochemical accumulator.
  • the envelope includes a structural weakness forming the weakened zone, the weakened zone being configured to rupture open under the effect of overpressure in the accumulator.
  • the heat transfer fluid is a non-flammable oil.
  • the heat transfer fluid has a viscosity of between 0.3 mm 2 .s and 5 mm 2 .s, preferably between 1 mm 2 .s and 5 mm 2 .s.
  • the battery further comprises a bladder assembled to the housing and configured to absorb pressure variations in the housing.
  • the battery further comprises a pressure sensor configured to detect excess pressure in the housing.
  • the housing comprises a valve configured to open during an overpressure in the housing and/or in said at least one accumulator.
  • the battery comprises several accumulators and several envelopes, the accumulators being arranged in series or in parallel in the housing, each envelope enclosing one of the accumulators.
  • Figure 1 schematically represents an accumulator comprising a perforated separator
  • Figure 2 schematically represents a battery pack according to one embodiment of the invention
  • Figure 3 represents an accumulator of the battery pack
  • Figure 4 is a detailed view of Figure 3
  • Figure 5 represents the battery pack according to another embodiment
  • Figure 6 is a sectional view of the battery pack of Figure 5.
  • Figure 2 shows a battery or battery pack 1 according to an exemplary embodiment of the invention.
  • the battery pack 1 comprises a housing 2 and several electrochemical accumulators or cells 3.
  • FIG. 2 An upper wall of the housing 2 is not shown in FIG. 2 but is visible in FIGS. 5 and 6 representing another embodiment.
  • the housing 2 is preferably rigid.
  • the housing 2 may be made of metallic material or composite material.
  • the housing 2 here has a parallelepiped shape but can of course have a different shape.
  • the accumulators 3 are arranged in series or in parallel in the housing 2.
  • the accumulators 3 of the same housing 2 form a module. Fourteen accumulators 3 are shown in FIG. 2.
  • the modules establish a first barrier to the propagation of a defect of an accumulator 3.
  • the presence of modules is optional. In the absence of a module, all the accumulators are combined in a single housing.
  • the integration of modules is dictated by reasons of manufacturability and maintenance of the battery pack.
  • the battery pack may comprise a housing (not shown) housing all of the modules.
  • said housing houses several housings 2.
  • connection bars 4 usually called busbars.
  • the busbars 4 are for example screwed or welded to the accumulators 3.
  • the busbars 4 allow the electrical connection between the accumulators 3.
  • the modules are also connected to each other, in particular by busbars 4.
  • the busbars 4 are for example made of copper.
  • Battery packs for high energy capacity applications comprise several electrochemical accumulators associated in series-parallel to meet the voltage, energy and power requirements of the intended application.
  • the voltage level is obtained by placing the accumulators in series and the energy and power level is obtained by placing the accumulators in parallel.
  • accumulators For safety reasons, achieving the voltage, energy and power levels requires accumulators to be grouped together to form a module. The modules are then positioned in parallel series to meet the specifications of the intended application.
  • each module comprises up to sixteen accumulators 3 connected in series, each module having a voltage of 60 V.
  • Nine modules can be connected together to obtain the desired voltage, for example 540 V in the case of a series connection of all the modules.
  • Each electrochemical accumulator 3 comprises an active part and an envelope 300.
  • the active part of the accumulator 3 comprises two electrodes, namely a cathode and an anode.
  • the active part also comprises at least one separator for insulating the electrodes from each other.
  • the assembly can be impregnated with a liquid or gelled electrolyte.
  • the active part of the accumulator thus comprises the electrodes, at least one separator, and an electrolyte.
  • these components or active part of the accumulator 3 are not shown in FIGS. 2 to 5 but are shown in FIG. 1 showing in a simplified manner the architecture of the accumulator 3.
  • Each envelope 300 contains the active part of one of the accumulators 3.
  • the envelope 300 is sealed or hermetic.
  • the casing 300 is generally rigid (hard).
  • the rigid casing 300 is made for example from a metallic material such as aluminum, nickel or steel.
  • the casing 300 can be flexible.
  • the flexible casing 300 is made with nylon-type materials.
  • the envelope 300 has a cylindrical shape.
  • the envelope 300 comprises a side wall 301 and transverse walls 302.
  • a transverse plane is understood to mean a plane orthogonal to a median plane of the envelope passing through a height of the envelope.
  • the envelope 300 may have a different shape, for example, prismatic (as is the case in FIG. 6), button (in English “button cell” whose shape is cylindrical and flat) or a so-called “pocket” format.
  • the envelope 300 may be formed in one piece or comprise several parts.
  • the envelope 300 comprises several parts.
  • the envelope 300 comprises a main body 303 and a closing disk 304.
  • the main body 303 is here substantially cylindrical.
  • the main body 303 is in particular cylindrical, the accumulator 3 having a generally cylindrical shape.
  • the main body 303 may have other shapes, for example oblong, oval, or having straight edges and rounded ends.
  • the main body 303 has on one end a transverse opening 305.
  • the closing disk 304 is assembled to the main body 303.
  • the closing disk 304 closes the transverse opening 305 of the main body 303.
  • the closing disk 304 thus forms one of the transverse walls 302 of the casing 300.
  • the casing 300 also comprises a seal 306.
  • the seal 306 is disposed between the main body 303 and the sealing disk 304.
  • the casing 303 comprises a weakened zone 307 configured to open under the effect of an overpressure in the accumulator 3.
  • the weakened zone 307 is a zone in which the casing 300 is weakened so that said zone is the first to open in the event of an overpressure in the accumulator 3.
  • the casing 300 may comprise a structural weakness forming the weakened zone 307.
  • the weakened zone 307 is calibrated and rated to open at a certain pressure level or threshold. Overpressure can occur in an accumulator 3 during thermal runaway thereof. This phenomenon is detailed later.
  • the structural weakness forms a mechanical fuse.
  • the structural weakness may typically be a reduction in the thickness of the envelope 300 over an area of the envelope 300.
  • the structural weakness may also be a local weakening, for example by marking or punching, on one of the walls of the envelope 300.
  • the weakened zone 307 is here formed in the transverse wall, here the closure disk 304.
  • the weakened zone 307 is formed by a boss made on the closure disk 304.
  • the boss is for example made by punching in order to locally weaken the closure disk 304.
  • the boss has a thickness less than the rest of the closure disk.
  • the weakened zone 307 can be provided elsewhere in the envelope 300, for example in the side wall 301.
  • the weakened zone 307 may be formed and/or have a shape other than a boss.
  • the weakened zone 307 is configured to open by rupture under the effect of the overpressure in the accumulator 3. When there is overpressure, the weakened zone 307 deforms to the point of opening the casing 300 at the level of said weakened zone 307. The size of the opening becomes increasingly larger depending on the pressure of the gases released by the accumulator 3.
  • the battery pack 1 further comprises a heat transfer fluid 5.
  • the heat transfer fluid is contained in the housing. The casing of each accumulator 3 is thus in contact with the heat transfer fluid.
  • the heat transfer fluid 5 exceeds the height of the accumulators 3. In other words, the heat transfer fluid 5 covers the accumulators 3.
  • a vacuum filling of the housing 2 with the heat transfer fluid 5 can be carried out. This makes it possible to guarantee a good distribution of the heat transfer fluid 5 over all of the accumulators 3 and to avoid trapping air bubbles in the housing 2 which could prevent contact of the heat transfer fluid 5 with the accumulators 3.
  • the battery pack 1 has an oil presence sensor to detect a possible leak in the pack housing.
  • the heat transfer fluid 5 has a viscosity such that, during an overpressure in one of the accumulators 3, the heat transfer fluid 5 penetrates through the open weakened zone 307 so as to cool the accumulator 3.
  • the heat transfer fluid 5 has a viscosity of between 0.3 mm 2 .s and 5 mm 2 .s, preferably between 1 mm 2 .s and 5 mm 2 .s.
  • the heat transfer fluid 5 is preferably non-flammable to avoid causing a fire within the battery pack 1.
  • the heat transfer fluid 5 is advantageously an oil.
  • the heat transfer fluid 5 is a synthetic oil.
  • the oil does not have a flash point and auto-ignition temperature.
  • the oil has the characteristic of being non-flammable, for example a non-flammable fluorinated type oil.
  • the heat transfer fluid 5 may be water, in particular demineralized water.
  • the temperature at the core of the accumulator 3 rises until it is no longer controllable. In particular, the temperature at the core of the accumulator 3 rises until it reaches a thermal runaway temperature Te. Due to the sealing of the accumulator 3 permitted by the casing 300, the pressure rises in the accumulator 3. When the accumulator 3 is under overpressure, the weakened zone 307 opens. The weakened zone 307 releases the electrolyte of the accumulator 3 in the form of flammable gases.
  • the accumulator 3 is overpressurized when it exceeds a threshold pressure Ps. This is the consequence of the temperature rise in the accumulator 3.
  • the threshold pressure Ps is for example between 13 and 15 bars.
  • the threshold pressure Ps is in particular between 13 and 15 bars for cylindrical 18650 accumulator formats.
  • Thermal runaway temperature Te is understood to mean a temperature threshold beyond which the temperature inside the accumulator rises in an uncontrolled manner. This threshold is reached when the exothermic reaction that occurs following a defect or abusive use of the accumulator cannot be cooled. In this case, the temperature continues to rise, self-feeding itself by this rise in temperature, and the defective accumulator enters a positive feedback process.
  • the thermal runaway temperature Te depends in particular on the components of the accumulator 3 and also on its state of charge (SoC for “State of Charge”) of the accumulator 3.
  • SoC state of charge
  • the thermal runaway temperature Te is revealed by measuring the temperature of the skin of the accumulator 3.
  • the accumulator 3 is considered to have gone into thermal runaway when the skin temperature Tp of the accumulator 3, i.e. the temperature taken on an external surface of the walls 301, 302 of the casing, reaches a temperature range of between 70°C and 120°C.
  • the temperatures of the gases generated by the thermal runaway at the core of the accumulator can exceed 800°C or even 1000°C.
  • the gases generated within the accumulator 3 by the exothermic reaction are released by the opening of the weakened zone 307, the pressure threshold Ps being reached.
  • the opening of the envelope can also be carried out at other locations on the envelope 300; producing an opening of the envelope through which the gases escape.
  • the gases evacuated at least in part from the accumulator by the weakened zone 307 are at least at the thermal runaway temperature or even at a higher temperature.
  • the gases come into contact with the heat transfer fluid 5 which changes phase, thus absorbing the calories evacuated by these hot gases.
  • the heat transfer fluid 5 thus locally contains the temperature.
  • the heat transfer fluid 5 comes into contact with the gases produced by the accumulator 3 outside and/or inside the accumulator.
  • the heat transfer fluid can come into contact with the gases evacuated by the weakened zone.
  • the heat transfer fluid 5 can also come into contact with the gases inside the accumulator 3.
  • the heat transfer fluid 5 enters through the weakened zone 307 of the casing 300 of the accumulator 3 and diffuses inside, mixing with the electrolyte and approaching the origin of the start of the thermal runaway.
  • the heat transfer fluid 5 comes into contact with the core of the accumulator 3.
  • the returning heat transfer fluid 5 migrates towards the core of the accumulator 3 and therefore near the central heating point to smother it. This prevents the thermal runaway from continuing to progress both inside the accumulator 3 and outside the accumulator 3. This also prevents the thermal runaway from spreading to neighboring accumulators 3. It is thus possible to circumscribe the source of the fault.
  • the present invention takes advantage of the property of the latent heat of vaporization of the heat transfer fluid 5 to contain the thermal runaway of the defective accumulator within the accumulator when the latter opens during a thermal runaway.
  • the heat transfer fluid 5 enters the accumulator 3 and dilutes in the liquid of the electrolyte of the accumulator 3 gradually reaching the contact of the zone where thermal heating has occurred.
  • the heat transfer fluid 5 enters the accumulator 3 contributing to reaching as close as possible to the heating that has been created in the accumulator 3. This makes it possible to act as close as possible to the defect and thus to stifle the heating.
  • the heat transfer fluid 5 has a liquid/gaseous state change temperature Te.
  • the heat transfer fluid 5 has a liquid/gaseous state change temperature Te higher than the skin temperature Tp of the envelope.
  • Te liquid/gaseous state change temperature
  • the liquid/gas state change temperature Te is higher than the skin temperature Tp of the casing when the weakened zone 307 is open. For example, thermal runaway generates a rise in the internal temperature such that the skin temperature Tp of the accumulator reaches a temperature between 70°C and 120°C and such that this rise in temperature also causes the weakened zone 307 to open, releasing hot gases.
  • the liquid/gas state change temperature Te is chosen so as to change phase when the heat transfer fluid is in contact with the hot gases. This change of phase can operate between 80°C and 250°C depending on the choice of the heat transfer fluid.
  • the liquid/gaseous state change temperature or threshold Te of the heat transfer fluid 5 is thus defined in relation to the skin temperature threshold Tp when the thermal runaway generates the opening of the weakened zone 307. This makes it possible to have the phase change of the heat transfer fluid at the moment when the hot gases leave the accumulator.
  • the temperatures of the hot gases leaving the accumulator being linked to the chemical components constituting the accumulator and also to the energy stored in the accumulator at the time of the thermal runaway, they extend from 70°C at the start of the runaway and rise very quickly towards 400°C to reach 1000°C if no measures are taken to contain the reaction.
  • the casing 300 necessarily opens at the weakened zone 307, the latter being calibrated for such an opening during an overpressure. It is possible that the casing 300 also opens at other locations, depending in particular on the intensity of the reaction within the accumulator 3, allowing at these locations also the contact of the heat transfer fluid 5 with the evacuated gases.
  • the returned heat transfer fluid 5 reaches the hot point and evaporates on contact with the hot parts and limits the temperature rise.
  • the heat transfer fluid 5 acts as a heat extractor.
  • the heat transfer fluid 5 prevents the remainder of the defective material of the accumulator 3 from contributing to the thermal runaway.
  • the heat transfer fluid 5 stabilizes and then stops the thermal runaway within the accumulator 3. Thus, by containing the thermal runaway at the source, this solution prevents the propagation of this thermal runaway to the adjacent accumulators 3.
  • the properties of the heat transfer fluid 5 are adapted to the needs of the accumulators 3 to contain their thermal runaway for the liquid/gaseous state change temperature Te. Depending on the chemistries of the accumulators and the energy stored at the time of thermal runaway, the thermal runaway threshold Te is different. Consequently, the formulation of the heat transfer fluid 5 must be adapted to have a liquid/gaseous phase change threshold Te compatible with the thermal runaway threshold Te.
  • the viscosity of the heat transfer fluid 5 can be chosen so as to allow the heat transfer fluid 5 to integrate the accumulator 3 when the weakened zone 307 of the casing 300 opens. In the event of opening also at other locations of the envelope 300 other than the weakened zone 307, the viscosity of the heat transfer fluid 5 also of course facilitates the penetration of the heat transfer fluid into the accumulator 3. It should be noted that the heat transfer fluid 5 passing into the gaseous state on contact with the gases produced by the accumulator 3, gains in viscosity when the temperature increases. This further facilitates the penetration of the heat transfer fluid 5 into the accumulator 3.
  • the heat transfer fluid 5 is a synthetic oil
  • the oil with its intrinsic dielectric strength properties also makes it possible to facilitate the integration of high-voltage batteries by reducing the insulation distances of the parts carried at high voltages and avoiding the risks of breakdown between the parts carried at high voltage and the walls of the housing 2 of the battery pack in which the elementary accumulators 3 are integrated and or of a housing of the module in the case of integration into the battery pack with modules.
  • the thermal runaway temperature Te begins between 70°C and 120°C and increases to reach temperatures of the order of 400 to 800°C or even 1000°C.
  • the external temperature Tp of the casing 300 is between 70°C and 120°C depending on the composition of the accumulators and the state of charge of the accumulator at the time of thermal runaway.
  • the heat transfer fluid 5 is chosen so as to have a liquid/gaseous state change temperature Te higher than the external temperature Tp of the casing 300, for example of the order of 130°C.
  • the accumulators 3 are separated from each other by a distance at least equal to 1 mm. This allows the heat transfer fluid 5 to effectively cool the accumulators 3.
  • the battery pack 1 may further comprise a bladder 6 assembled to the housing 2 (visible in the exemplary embodiment illustrated in FIGS. 5 and 6).
  • the bladder 6 is configured to absorb pressure variations in the housing.
  • the bladder 6 may be elastic and inflatable.
  • the bladder 6 initially compensates for the excess pressure produced during the failure of an accumulator 3 and prevents the walls of the housing 2 of the battery pack 1 from being subjected to this excess pressure.
  • the bladder can also compensate for pressure variations linked to the expansion of the heat transfer fluid depending on environmental conditions (temperature, altitude).
  • the bladder can be made of aluminum.
  • One or more bladders may be arranged as needed.
  • bladders may be positioned at the modules or at the battery pack.
  • the battery pack 1 may further comprise a pressure sensor (not shown).
  • the pressure sensor is configured to measure a pressure in the housing 2 and/or to detect an overpressure in the housing.
  • the pressure sensor can be integrated into the bladder 6.
  • the pressure sensor may be mounted on an internal wall of the housing 2.
  • the pressure sensor is configured to generate, via a contactor, an electrical signal corresponding to information representative of said pressure.
  • the pressure sensor can be configured to send a warning signal in the event of overpressure in the housing.
  • the pressure sensor can also be configured to give an order to isolate the battery pack by opening a contactor at the output of the battery pack 1.
  • the heat transfer fluid presence sensor is present in the battery pack 1 (not shown). It is configured to detect a leak of the heat transfer fluid.
  • the housing may further comprise a valve 7 (visible in FIGS. 5 and 6) configured to open in the event of excess pressure in the battery pack 1 and/or in the housing 2 of one of the modules.
  • a valve 7 visible in FIGS. 5 and 6) configured to open in the event of excess pressure in the battery pack 1 and/or in the housing 2 of one of the modules.
  • the valve 7 comprises, for example, conduits allowing fumes to escape to the outside of the housing 2 in the event of a malfunction of the battery pack 1.
  • the valve 7 also makes it possible to evacuate fumes from the heat transfer fluid in the event of gas being released from an accumulator 3 or from several accumulators 3 which could go into thermal runaway simultaneously.
  • the heat transfer fluid can also be contained in said housing.
  • the invention a reduction in the risk or even an absence of fire is obtained when the accumulator goes into thermal runaway.
  • the properties of the heat transfer fluid facilitate the heat exchanges of the accumulator with the outside by boiling as close as possible to the threshold for triggering the accumulator in thermal runaway.
  • This boiling and the infiltration of the heat transfer fluid through the weakened zone of the casing of the accumulator that is going into runaway help to contain the runaway and reduce the projections of flame and hot smoke that can be extracted from the accumulator during such defects.
  • the heat transfer fluid absorbs the excess pressure generated during the explosion of the accumulator, thus reducing the mechanical stresses in the casing and the housing of the battery pack.
  • the invention makes it possible to cool the accumulators in the nominal operating mode and to indirectly improve the reliability of the accumulators.
  • the invention benefits any type of battery subject to thermal runaway, particularly in cases of extreme use such as the cases listed below but not limited to shocks, internal and external short circuits and abusive temperature conditions.

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Abstract

The invention relates to a battery comprising: - at least one electrochemical accumulator (3) including an active portion and a shell enclosing the active portion; - a casing (2) housing the at least one accumulator (3); and - a heat-transfer fluid (5) contained in the casing (2), the shell (300) including a weakened zone configured to open under the effect of an overpressure in the accumulator (3) and to discharge gases produced by the active portion of the accumulator (3) that caused the overpressure. During the overpressure in the at least one accumulator (3), the heat-transfer fluid (5) comes into contact with the gases produced by the accumulator (3) so as to contain the gases and cool the accumulator.

Description

DESCRIPTION DESCRIPTION

Titre de l’invention : Pack-batterie comportant un fluide caloporteur apte à contenir l’emballement thermique des accumulateurs électrochimiques du pack-batterieTitle of the invention: Battery pack comprising a heat transfer fluid capable of containing the thermal runaway of the electrochemical accumulators of the battery pack

[0001] L’invention se rapporte au domaine des batteries comportant des accumulateurs électrochimiques, notamment des accumulateurs à électrolyte liquide et/ou gélifiée. Elles sont composées par deux électrodes (cathode et anode) séparées par une membrane isolante (ou séparateur) et le tout plongé dans une électrolyte liquide ou gélifiée. [0001] The invention relates to the field of batteries comprising electrochemical accumulators, in particular accumulators with liquid and/or gel electrolyte. They are composed of two electrodes (cathode and anode) separated by an insulating membrane (or separator) and the whole immersed in a liquid or gel electrolyte.

[0002] Les composés chimiques utilisés sont multiples pour obtenir des accumulateurs à forte capacité. Le composé le plus couramment utilisé actuellement, est associé à la famille de technologie dite Lithium-Ion, et des sous-familles existent utilisant d’autres associations de matériaux chimiques tels que le Lithium Fer Phosphate (LFP), le Lithium-Cobalt-Oxyde (LCO), le Lithium Nickel Cobalt Aluminium (NCA) et le Lithium Nickel Manganèse Cobalt (NMC). A ces sous-familles d’autres associations sont à l’étude avec des composés de Lithium solide et de Lithium-Air. Une autre famille émerge pour palier au problème d’approvisionnement du lithium, il s’agit de la technologie Sodium-Ion. [0002] The chemical compounds used are multiple to obtain high capacity accumulators. The most commonly used compound currently is associated with the family of technology called Lithium-Ion, and subfamilies exist using other associations of chemical materials such as Lithium Iron Phosphate (LFP), Lithium-Cobalt-Oxide (LCO), Lithium Nickel Cobalt Aluminum (NCA) and Lithium Nickel Manganese Cobalt (NMC). In addition to these subfamilies, other associations are being studied with solid Lithium and Lithium-Air compounds. Another family is emerging to overcome the problem of lithium supply, this is Sodium-Ion technology.

[0003] Ces accumulateurs embarquent de fortes capacités énergétiques pour répondre aux besoins des applications. Une forte capacité énergétique est notamment utile dans le domaine des transports. Ces accumulateurs sont assemblés dans des packs batteries pour intégrer dans des systèmes propulsifs, qui sont dits tout électrique lorsque la batterie (ou pack-batterie) est l’unique source d’énergie ou dit hybridé lorsque le pack-batterie partage l’apport en énergie avec une autre source d’énergie. Ces accumulateurs sont aussi utilisés pour constituer des pack-batteries de forte capacité pour répondre à un besoin de stockage d’énergie dit stationnaire tel que le stockage d’énergies renouvelables sur les réseaux électriques. Les domaines d'application sont vastes et ne se limitent pas au domaine du transport terrestre et aéronautique, et des réseaux électriques. Aussi, l’application de la présente invention concerne tous les domaines qui peuvent utiliser des accumulateurs électrochimiques de forte capacité sujets à partir en emballement thermique en cas d’usages abusifs. [0003] These accumulators have high energy capacities to meet the needs of the applications. A high energy capacity is particularly useful in the field of transport. These accumulators are assembled in battery packs to integrate into propulsion systems, which are called all-electric when the battery (or battery pack) is the sole source of energy or called hybridized when the battery pack shares the energy supply with another source of energy. These accumulators are also used to constitute high-capacity battery packs to meet a need for so-called stationary energy storage such as the storage of renewable energies on electrical networks. The fields of application are vast and are not limited to the field of land and aeronautical transport, and electrical networks. Also, the application of the present invention concerns all fields that can use high-capacity electrochemical accumulators subject to thermal runaway in the event of abusive use.

[0004] L’origine de l’emballement thermique peut être liée à des altérations internes de l’accumulateur (dégradation des matériaux de l’accumulateur générant un court- circuit interne, telle qu’une perforation d’un séparateur par l’apparition de dendrites). La figure 1 illustre de manière schématique une perforation P d’un séparateur S d’un accumulateur entre une anode A et une cathode C. L’emballement thermique peut également être lié à des conditions externes abusives environnementales (température, vibrations, chocs) et/ou fonctionnelles à la charge ou décharge des accumulateurs. [0004] The origin of thermal runaway may be linked to internal alterations of the accumulator (degradation of the accumulator materials generating a short- internal circuit, such as a perforation of a separator by the appearance of dendrites). Figure 1 schematically illustrates a perforation P of a separator S of an accumulator between an anode A and a cathode C. Thermal runaway can also be linked to abusive external environmental conditions (temperature, vibrations, shocks) and/or functional conditions during the charging or discharging of the accumulators.

[0005] Ces altérations internes ou conditions abusives d’emploi génèrent des échauffements thermiques au sein des accumulateurs élémentaires qui conduisent à l’emballement thermique de ces derniers et peuvent être à l’origine de départ de fumées/gaz voire de feu. [0005] These internal alterations or abusive conditions of use generate thermal heating within the elementary accumulators which lead to thermal runaway of the latter and can be the cause of smoke/gas or even fire.

[0006] A titre d’illustration, à chaud, un accumulateur électrochimique doit fonctionner dans une plage de température définie, généralement inférieure à 70°C à sa surface extérieure. Au-delà de la plage de température définie, des dégradations sur les matériaux constituant l’accumulateur se produisent et sont à l’origine de l’emballement thermique dans l’accumulateur. L’emballement thermique se maintient dans l’accumulateur lorsque l’énergie dégagée par les réactions exothermiques qui surviennent à l’intérieur de celui-ci, excède la capacité à la dissiper à l’extérieur ainsi que lorsque l’accumulateur défectueux ne peut pas être isolé pour le refroidir. [0006] As an illustration, when hot, an electrochemical accumulator must operate within a defined temperature range, generally less than 70°C at its external surface. Beyond the defined temperature range, damage to the materials constituting the accumulator occurs and is the cause of thermal runaway in the accumulator. Thermal runaway continues in the accumulator when the energy released by the exothermic reactions occurring inside the accumulator exceeds the capacity to dissipate it to the outside and when the defective accumulator cannot be isolated to cool it.

[0007] En outre, dans ce type de batteries, l’emballement thermique peut démarrer dans un accumulateur et se propager à un ou plusieurs accumulateurs voisins, voire à l’ensemble de la batterie. [0007] Furthermore, in this type of battery, thermal runaway can start in one accumulator and spread to one or more neighboring accumulators, or even to the entire battery.

[0008] Il est donc nécessaire de contenir l’emballement thermique des accumulateurs de batteries. [0008] It is therefore necessary to contain the thermal runaway of battery accumulators.

[0009] Des solutions pour refroidir les batteries existent. On connaît par exemple le document DE 122013017396A1 qui divulgue une batterie comprenant un boîtier dans lequel sont disposées des cellules/accumulateurs. Les cellules sont baignées dans un fluide contenu dans le boîtier afin de contrôler leur température. [0009] Solutions for cooling batteries exist. For example, document DE 122013017396A1 is known, which discloses a battery comprising a housing in which cells/accumulators are arranged. The cells are bathed in a fluid contained in the housing in order to control their temperature.

[0010] L’invention vise à améliorer cette solution non seulement en refroidissant les accumulateurs mais surtout en circonscrivant, en cas d’emballement thermique démarrant dans un accumulateur, l’emballement thermique à l’accumulateur concerné uniquement. [0011] L’invention propose à cet effet une batterie comportant : au moins un accumulateur électrochimique comprenant une partie active et une enveloppe renfermant ladite partie active ; un boîtier logeant ledit au moins un accumulateur ; et un fluide caloporteur contenu dans le boîtier, l’enveloppe comprenant une zone fragilisée configurée pour s’ouvrir sous l’effet d’une surpression dans l’accumulateur et pour évacuer des gaz produits par la partie active de l’accumulateur à l’origine de la surpression. [0010] The invention aims to improve this solution not only by cooling the accumulators but above all by limiting, in the event of thermal runaway starting in an accumulator, the thermal runaway to the accumulator concerned only. [0011] The invention proposes for this purpose a battery comprising: at least one electrochemical accumulator comprising an active part and an envelope enclosing said active part; a housing housing said at least one accumulator; and a heat transfer fluid contained in the housing, the envelope comprising a weakened zone configured to open under the effect of an overpressure in the accumulator and to evacuate gases produced by the active part of the accumulator causing the overpressure.

Lors de la surpression dans ledit au moins un accumulateur, ledit fluide caloporteur entre en contact avec les gaz produits par l’accumulateur de sorte à contenir lesdits gaz et refroidir l’accumulateur. When the pressure in said at least one accumulator is increased, said heat transfer fluid comes into contact with the gases produced by the accumulator so as to contain said gases and cool the accumulator.

Lors d’une surpression dans ledit au moins un accumulateur, le fluide caloporteur au contact avec les gaz produits par l’accumulateur, passe d’un état liquide à un état gazeux. When there is excess pressure in said at least one accumulator, the heat transfer fluid in contact with the gases produced by the accumulator changes from a liquid state to a gaseous state.

[0012] La solution apportée par l’invention permet ainsi de contenir le départ d’un emballement thermique causant une surpression dans l’accumulateur défectueux en contenant directement les gaz produits par l’accumulateur. L’ouverture de la zone fragilisée de l’enveloppe de l’accumulateur défectueux permet au fluide d’accéder rapidement aux gaz produits par l’accumulateur, et ainsi de circonscrire l’emballement thermique au plus près de son origine et éviter sa progression au cœur de l’accumulateur. [0012] The solution provided by the invention thus makes it possible to contain the start of a thermal runaway causing excess pressure in the defective accumulator by directly containing the gases produced by the accumulator. Opening the weakened zone of the casing of the defective accumulator allows the fluid to quickly access the gases produced by the accumulator, and thus to circumscribe the thermal runaway as close as possible to its origin and prevent its progression to the heart of the accumulator.

[0013] L’invention réduit le risque de propagation d’un emballement thermique aux cellules adjacentes en refroidissant directement et rapidement l’accumulateur défectueux. [0013] The invention reduces the risk of thermal runaway spreading to adjacent cells by directly and rapidly cooling the defective accumulator.

[0014] Des caractéristiques préférées particulières commodes de la batterie selon l’invention sont présentées ci-dessous. [0014] Particular preferred convenient features of the battery according to the invention are presented below.

[0015] Lors d’une surpression dans ledit au moins un accumulateur, le fluide caloporteur pénètre par la zone fragilisée ouverte de sorte à contenir au moins une partie des gaz produits par l’accumulateur. [0015] During an overpressure in said at least one accumulator, the heat transfer fluid enters through the open weakened zone so as to contain at least part of the gases produced by the accumulator.

[0016] Lors d’une surpression dans ledit au moins un accumulateur, le fluide caloporteur entre en contact, à l’extérieur de l’accumulateur, avec au moins une partie des gaz évacués. [0017] Le fluide caloporteur a une température de changement d’état liquide/gazeux supérieure à une température de peau lors d’un emballement thermique à l’origine de l’ouverture de la zone fragilisée dudit au moins un accumulateur électrochimique. [0016] During an overpressure in said at least one accumulator, the heat transfer fluid comes into contact, outside the accumulator, with at least part of the evacuated gases. [0017] The heat transfer fluid has a liquid/gaseous state change temperature higher than a skin temperature during thermal runaway causing the opening of the weakened zone of said at least one electrochemical accumulator.

[0018] L’enveloppe comprend une faiblesse structurelle formant la zone fragilisée, la zone fragilisée étant configurée pour s’ouvrir par rupture sous l’effet de la surpression dans l’accumulateur. [0018] The envelope includes a structural weakness forming the weakened zone, the weakened zone being configured to rupture open under the effect of overpressure in the accumulator.

[0019] Le fluide caloporteur est une huile ininflammable. [0019] The heat transfer fluid is a non-flammable oil.

[0020] Le fluide caloporteur a une viscosité comprise entre 0,3 mm2.s et 5 mm2.s, de préférence entre 1 mm2.s et 5 mm2.s. [0020] The heat transfer fluid has a viscosity of between 0.3 mm 2 .s and 5 mm 2 .s, preferably between 1 mm 2 .s and 5 mm 2 .s.

[0021] La batterie comporte en outre une vessie assemblée au boîtier et configurée pour absorber des variations de pression dans le boîtier. [0021] The battery further comprises a bladder assembled to the housing and configured to absorb pressure variations in the housing.

[0022] La batterie comporte en outre un capteur de pression configuré pour détecter une surpression dans le boîtier. [0022] The battery further comprises a pressure sensor configured to detect excess pressure in the housing.

[0023] Le boîtier comprend un clapet configuré pour s’ouvrir lors d’une surpression dans le boîtier et/ou dans ledit au moins un accumulateur. [0023] The housing comprises a valve configured to open during an overpressure in the housing and/or in said at least one accumulator.

[0024] La batterie comporte plusieurs accumulateurs et plusieurs enveloppes, les accumulateurs étant agencés en série ou en parallèle dans le boîtier, chaque enveloppe renfermant l’un des accumulateurs. [0024] The battery comprises several accumulators and several envelopes, the accumulators being arranged in series or in parallel in the housing, each envelope enclosing one of the accumulators.

[0025] D’autres particularités et avantages de l’invention apparaîtront encore dans la description ci-après en référence aux dessins annexés, donnés à titre d’exemple non limitatifs: [0025] Other features and advantages of the invention will become apparent in the description below with reference to the attached drawings, given as non-limiting examples:

La figure 1 représente schématiquement un accumulateur comportant un séparateur perforé ; la figure 2 représente schématiquement un pack-batterie selon un mode de réalisation de l’invention ; la figure 3 représente un accumulateur du pack-batterie ; la figure 4 est une vue de détail de la figure 3 ; la figure 5 représente le pack-batterie selon un autre mode de réalisation ; et la figure 6 est une vue de coupe du pack-batterie de la figure 5. [0026] La figure 2 représente une batterie ou pack-batterie 1 selon un exemple de réalisation de l’invention. Figure 1 schematically represents an accumulator comprising a perforated separator; Figure 2 schematically represents a battery pack according to one embodiment of the invention; Figure 3 represents an accumulator of the battery pack; Figure 4 is a detailed view of Figure 3; Figure 5 represents the battery pack according to another embodiment; and Figure 6 is a sectional view of the battery pack of Figure 5. [0026] Figure 2 shows a battery or battery pack 1 according to an exemplary embodiment of the invention.

[0027] Le pack-batterie 1 comporte un boîtier 2 et plusieurs accumulateurs ou cellules 3 électrochimiques. [0027] The battery pack 1 comprises a housing 2 and several electrochemical accumulators or cells 3.

[0028] Une paroi supérieure du boîtier 2 n’est pas représentée sur la figure 2 mais est visible sur les figures 5 et 6 représentant un autre mode de réalisation. [0028] An upper wall of the housing 2 is not shown in FIG. 2 but is visible in FIGS. 5 and 6 representing another embodiment.

[0029] Le boîtier 2 est de préférence rigide. Le boîtier 2 peut être réalisé en matériau métallique ou en matériau composite. [0029] The housing 2 is preferably rigid. The housing 2 may be made of metallic material or composite material.

[0030] Le boîtier 2 présente ici une forme parallélépipède mais peut bien entendu présenter une forme différente. [0030] The housing 2 here has a parallelepiped shape but can of course have a different shape.

[0031] Les accumulateurs 3 sont agencés en série ou en parallèle dans le boîtier 2. Les accumulateurs 3 d’un même boîtier 2 forment un module. Quatorze accumulateurs 3 sont représentés à la figure 2. [0031] The accumulators 3 are arranged in series or in parallel in the housing 2. The accumulators 3 of the same housing 2 form a module. Fourteen accumulators 3 are shown in FIG. 2.

[0032] Les modules établissent une première barrière à la propagation d’un défaut d’un accumulateur 3. La présence de modules est optionnelle. En l’absence de module, tous les accumulateurs sont réunis dans un unique boîtier. L’intégration de module est dictée par des raisons de fabricabilité et de maintenance du pack-batterie. [0032] The modules establish a first barrier to the propagation of a defect of an accumulator 3. The presence of modules is optional. In the absence of a module, all the accumulators are combined in a single housing. The integration of modules is dictated by reasons of manufacturability and maintenance of the battery pack.

[0033] Le pack-batterie peut comprendre un boîtier (non représenté) logeant l’ensemble des modules. Autrement dit, ledit boîtier loge plusieurs boîtiers 2. [0033] The battery pack may comprise a housing (not shown) housing all of the modules. In other words, said housing houses several housings 2.

[0034] Les accumulateurs 3 sont reliées entre eux, généralement par des barres de connexion 4, appelées usuellement busbars. Les busbars 4 sont par exemple vissés ou soudés aux accumulateurs 3. Les busbars 4 permettent la connexion électrique entre les accumulateurs 3. [0034] The accumulators 3 are connected to each other, generally by connection bars 4, usually called busbars. The busbars 4 are for example screwed or welded to the accumulators 3. The busbars 4 allow the electrical connection between the accumulators 3.

[0035] Les modules sont également reliés entre eux, notamment par des busbars 4. [0035] The modules are also connected to each other, in particular by busbars 4.

[0036] Les busbars 4 sont par exemple en cuivre. [0036] The busbars 4 are for example made of copper.

[0037] Les pack-batteries pour les applications à forte capacité énergétique comportent plusieurs accumulateurs électrochimiques associés en série - parallèle pour répondre aux besoins de tensions, d’énergie et de puissance de l’application visée. Le niveau de tension est obtenu par la mise en série des accumulateurs et le niveau d’énergie et de puissance est obtenu par une mise en parallèle des accumulateurs. Pour des raisons de sécurité, la réalisation des niveaux de tension, d’énergie et de puissance nécessite de réunir les accumulateurs par groupe pour constituer un module. Les modules sont ensuite positionnés en série parallèle pour satisfaire le cahier des charges de l’application visée. [0037] Battery packs for high energy capacity applications comprise several electrochemical accumulators associated in series-parallel to meet the voltage, energy and power requirements of the intended application. The voltage level is obtained by placing the accumulators in series and the energy and power level is obtained by placing the accumulators in parallel. accumulators. For safety reasons, achieving the voltage, energy and power levels requires accumulators to be grouped together to form a module. The modules are then positioned in parallel series to meet the specifications of the intended application.

[0038] Par exemple, chaque module comprend jusqu’à seize accumulateurs 3 reliées en série, chaque module ayant une tension de 60V. Neuf modules peuvent être reliés entre eux pour obtenir la tension souhaitée, par exemple de 540V dans un cas d’une connexion en série de l’ensemble des modules. [0038] For example, each module comprises up to sixteen accumulators 3 connected in series, each module having a voltage of 60 V. Nine modules can be connected together to obtain the desired voltage, for example 540 V in the case of a series connection of all the modules.

[0039] Chaque accumulateur 3 électrochimique comprend une partie active et une enveloppe 300. [0039] Each electrochemical accumulator 3 comprises an active part and an envelope 300.

[0040] La partie active de l’accumulateur 3 comprend deux électrodes, à savoir une cathode et une anode. La partie active comprend également au moins un séparateur pour isoler les électrodes entre elles. L’ensemble peut être imprégné par un électrolyte liquide ou gélifié. La partie active de l’accumulateur comprend ainsi les électrodes, au moins un séparateur, et un électrolyte. Par souci de simplification, ces composants ou partie active de l’accumulateur 3 ne sont pas représentés sur les figures 2 à 5 mais le sont sur la figure 1 montrant de manière simplifiée l’architecture de l’accumulateur 3. [0040] The active part of the accumulator 3 comprises two electrodes, namely a cathode and an anode. The active part also comprises at least one separator for insulating the electrodes from each other. The assembly can be impregnated with a liquid or gelled electrolyte. The active part of the accumulator thus comprises the electrodes, at least one separator, and an electrolyte. For the sake of simplification, these components or active part of the accumulator 3 are not shown in FIGS. 2 to 5 but are shown in FIG. 1 showing in a simplified manner the architecture of the accumulator 3.

[0041] Chaque enveloppe 300 renferme la partie active de l’un des accumulateurs 3. L’enveloppe 300 est étanche ou hermétique. [0041] Each envelope 300 contains the active part of one of the accumulators 3. The envelope 300 is sealed or hermetic.

[0042] L’enveloppe 300 est généralement rigide (dure). L’enveloppe 300 rigide est fabriquée par exemple à partir d’un matériau métallique de type aluminium, nickel ou acier. Selon un autre exemple de réalisation, l’enveloppe 300 peut être souple. L’enveloppe 300 souple est fabriquée avec des matériaux de type nylon. [0042] The casing 300 is generally rigid (hard). The rigid casing 300 is made for example from a metallic material such as aluminum, nickel or steel. According to another exemplary embodiment, the casing 300 can be flexible. The flexible casing 300 is made with nylon-type materials.

[0043] Dans l’exemple illustré aux figures 2 à 4, l’enveloppe 300 présente une forme cylindrique. L’enveloppe 300 comprend une paroi latérale 301 et des parois transversales 302. [0043] In the example illustrated in Figures 2 to 4, the envelope 300 has a cylindrical shape. The envelope 300 comprises a side wall 301 and transverse walls 302.

[0044] On entend par plan transversal un plan orthogonal à un plan médian de l’enveloppe passant par une hauteur de l’enveloppe. [0045] L’enveloppe 300 peut présenter une forme différente par exemple, prismatique (comme c’est le cas en figure 6), bouton (en anglais "button cell” dont la forme est cylindrique et plate) ou un format dit « poche » (Pouch). [0044] A transverse plane is understood to mean a plane orthogonal to a median plane of the envelope passing through a height of the envelope. [0045] The envelope 300 may have a different shape, for example, prismatic (as is the case in FIG. 6), button (in English “button cell” whose shape is cylindrical and flat) or a so-called “pocket” format.

[0046] L’enveloppe 300 peut être formée d’un seul tenant ou comprendre plusieurs parties. [0046] The envelope 300 may be formed in one piece or comprise several parts.

[0047] Dans l’exemple représenté aux figures 3 et 4, l’enveloppe 300 comprend plusieurs parties. En particulier, l’enveloppe 300 comprend un corps principal 303 et un disque d’obturation 304. [0047] In the example shown in Figures 3 and 4, the envelope 300 comprises several parts. In particular, the envelope 300 comprises a main body 303 and a closing disk 304.

[0048] Le corps principal 303 est ici sensiblement cylindrique. Le corps principal 303 est notamment cylindrique, l’accumulateur 3 présentant une forme générale cylindrique. En variantes, le corps principal 303 peut présenter d’autres formes, par exemple oblongue, ovale, ou ayant des bords droits et des extrémités arrondies. [0048] The main body 303 is here substantially cylindrical. The main body 303 is in particular cylindrical, the accumulator 3 having a generally cylindrical shape. As variants, the main body 303 may have other shapes, for example oblong, oval, or having straight edges and rounded ends.

[0049] Le corps principal 303 présente sur une extrémité une ouverture transversale 305. [0049] The main body 303 has on one end a transverse opening 305.

[0050] Le disque d’obturation 304 est assemblé au corps principal 303. Le disque d’obturation 304 obture l’ouverture transversale 305 du corps principal 303. Le disque d’obturation 304 forme ainsi l’une des parois transversales 302 de l’enveloppe 300. [0050] The closing disk 304 is assembled to the main body 303. The closing disk 304 closes the transverse opening 305 of the main body 303. The closing disk 304 thus forms one of the transverse walls 302 of the casing 300.

[0051] L’enveloppe 300 comprend également un joint d’étanchéité 306. Le joint d’étanchéité 306 est disposé entre le corps principal 303 et le disque d’obturation 304. [0051] The casing 300 also comprises a seal 306. The seal 306 is disposed between the main body 303 and the sealing disk 304.

[0052] L’enveloppe 303 comprend une zone fragilisée 307 configurée pour s’ouvrir sous l’effet d’une surpression dans l’accumulateur 3. La zone fragilisée 307 est une zone dans laquelle l’enveloppe 300 est fragilisée de sorte que ladite zone soit la première à s’ouvrir en cas de surpression dans l’accumulateur 3. Autrement dit, l’enveloppe 300 peut comprendre une faiblesse structurelle formant la zone fragilisée 307 [0052] The casing 303 comprises a weakened zone 307 configured to open under the effect of an overpressure in the accumulator 3. The weakened zone 307 is a zone in which the casing 300 is weakened so that said zone is the first to open in the event of an overpressure in the accumulator 3. In other words, the casing 300 may comprise a structural weakness forming the weakened zone 307.

[0053] La zone fragilisée 307 est calibrée et tarée pour s’ouvrir à un certain niveau ou seuil de pression. La surpression peut survenir dans un accumulateur 3 lors d’un emballement thermique de celui-ci. Ce phénomène est détaillé plus loin. [0054] La faiblesse structurelle forme un fusible mécanique. La faiblesse structurelle peut être typiquement une réduction de l’épaisseur de l’enveloppe 300 sur une zone de l’enveloppe 300. La faiblesse structurelle peut également être un affaiblissement local, par exemple par un marquage ou poinçonnage, sur l’une des parois de l’enveloppe 300. [0053] The weakened zone 307 is calibrated and rated to open at a certain pressure level or threshold. Overpressure can occur in an accumulator 3 during thermal runaway thereof. This phenomenon is detailed later. [0054] The structural weakness forms a mechanical fuse. The structural weakness may typically be a reduction in the thickness of the envelope 300 over an area of the envelope 300. The structural weakness may also be a local weakening, for example by marking or punching, on one of the walls of the envelope 300.

[0055] La zone fragilisée 307 est ici formée dans la paroi transversale, ici le disque d’obturation 304. La zone fragilisée 307 est formée par un bossage réalisée sur le disque d’obturation 304. Le bossage est par exemple réalisé par poinçonnage afin de fragiliser localement le disque d’obturation 304. Le bossage présente une épaisseur plus faible que le reste du disque d’obturation. [0055] The weakened zone 307 is here formed in the transverse wall, here the closure disk 304. The weakened zone 307 is formed by a boss made on the closure disk 304. The boss is for example made by punching in order to locally weaken the closure disk 304. The boss has a thickness less than the rest of the closure disk.

[0056] La zone fragilisée 307 peut être ménagée ailleurs dans l’enveloppe 300, par exemple dans la paroi latérale 301 . [0056] The weakened zone 307 can be provided elsewhere in the envelope 300, for example in the side wall 301.

[0057] La zone fragilisée 307 peut être formée et/ou présenter une autre forme qu’un bossage. [0057] The weakened zone 307 may be formed and/or have a shape other than a boss.

[0058] La zone fragilisée 307 est configurée pour s’ouvrir par rupture sous l’effet de la surpression dans l’accumulateur 3. Lorsqu’il y a surpression, la zone fragilisée 307 se déforme allant jusqu’à l’ouverture de l’enveloppe 300 au niveau de ladite zone fragilisée 307. La taille de l’ouverture devient de plus en plus grande en fonction de la pression des gaz dégagés par l’accumulateur 3. [0058] The weakened zone 307 is configured to open by rupture under the effect of the overpressure in the accumulator 3. When there is overpressure, the weakened zone 307 deforms to the point of opening the casing 300 at the level of said weakened zone 307. The size of the opening becomes increasingly larger depending on the pressure of the gases released by the accumulator 3.

[0059] Le pack-batterie 1 comprend en outre un fluide caloporteur 5. Le fluide caloporteur est contenu dans le boîtier. L’enveloppe de chaque accumulateur 3 est ainsi en contact avec le fluide caloporteur. [0059] The battery pack 1 further comprises a heat transfer fluid 5. The heat transfer fluid is contained in the housing. The casing of each accumulator 3 is thus in contact with the heat transfer fluid.

[0060] Le fluide caloporteur 5 dépasse en hauteur les accumulateurs 3. Autrement dit, le fluide caloporteur 5 recouvre les accumulateurs 3. [0060] The heat transfer fluid 5 exceeds the height of the accumulators 3. In other words, the heat transfer fluid 5 covers the accumulators 3.

[0061] Un remplissage sous vide du boîtier 2 par le fluide caloporteur 5 peut être réalisé. Cela permet de garantir une bonne répartition du fluide caloporteur 5 sur l’ensemble des accumulateurs 3 et d’éviter d’emprisonner des bulles d’air dans le boîtier 2 qui pourraient éviter un contact du fluide caloporteur 5 avec les accumulateurs 3. [0061] A vacuum filling of the housing 2 with the heat transfer fluid 5 can be carried out. This makes it possible to guarantee a good distribution of the heat transfer fluid 5 over all of the accumulators 3 and to avoid trapping air bubbles in the housing 2 which could prevent contact of the heat transfer fluid 5 with the accumulators 3.

[0062] Le pack batterie 1 dispose d’un capteur de présence d’huile pour détecter une éventuelle fuite dans le boîtier du pack. [0063] Le fluide caloporteur 5 a une viscosité telle que, lors d’une surpression dans l’une des accumulateurs 3, le fluide caloporteur 5 pénètre par la zone fragilisée 307 ouverte de sorte à refroidir l’accumulateur 3. [0062] The battery pack 1 has an oil presence sensor to detect a possible leak in the pack housing. [0063] The heat transfer fluid 5 has a viscosity such that, during an overpressure in one of the accumulators 3, the heat transfer fluid 5 penetrates through the open weakened zone 307 so as to cool the accumulator 3.

[0064] Typiquement, le fluide caloporteur 5 a une viscosité comprise entre 0,3 mm2.s et 5 mm2.s, de préférence entre 1 mm2.s et 5 mm2.s. [0064] Typically, the heat transfer fluid 5 has a viscosity of between 0.3 mm 2 .s and 5 mm 2 .s, preferably between 1 mm 2 .s and 5 mm 2 .s.

[0065] Le fluide caloporteur 5 est de préférence ininflammable pour éviter de produire un feu au sein du pack-batterie 1 . [0065] The heat transfer fluid 5 is preferably non-flammable to avoid causing a fire within the battery pack 1.

[0066] Le fluide caloporteur 5 est avantageusement une huile. [0066] The heat transfer fluid 5 is advantageously an oil.

[0067] De préférence, le fluide caloporteur 5 est une huile synthétique. [0067] Preferably, the heat transfer fluid 5 is a synthetic oil.

[0068] De préférence, l’huile ne présente pas de point éclair et de température d’auto-inflammation. Autrement dit, l’huile présente la caractéristique d’être ininflammable, par exemple une huile de type fluoré ininflammable. [0068] Preferably, the oil does not have a flash point and auto-ignition temperature. In other words, the oil has the characteristic of being non-flammable, for example a non-flammable fluorinated type oil.

[0069] Selon un autre exemple de réalisation, le fluide caloporteur 5 peut être de l’eau, notamment de l’eau déminéralisée. [0069] According to another exemplary embodiment, the heat transfer fluid 5 may be water, in particular demineralized water.

[0070] Lors d’un emballement thermique d’un accumulateur 3, la température au cœur de l’accumulateur 3 monte jusqu’à ne plus être maîtrisable. En particulier, la température au cœur de l’accumulateur 3 monte jusqu’à atteindre une température d’emballement thermique Te. Du fait de l’étanchéité de l’accumulateur 3 permise par l’enveloppe 300, la pression monte dans l’accumulateur 3. Lorsque l’accumulateur 3 se trouve en surpression, la zone fragilisée 307 s’ouvre. La zone fragilisée 307 libère l’électrolyte de l’accumulateur 3 sous forme de gaz inflammables. [0070] During thermal runaway of an accumulator 3, the temperature at the core of the accumulator 3 rises until it is no longer controllable. In particular, the temperature at the core of the accumulator 3 rises until it reaches a thermal runaway temperature Te. Due to the sealing of the accumulator 3 permitted by the casing 300, the pressure rises in the accumulator 3. When the accumulator 3 is under overpressure, the weakened zone 307 opens. The weakened zone 307 releases the electrolyte of the accumulator 3 in the form of flammable gases.

[0071] L’accumulateur 3 est en surpression lorsqu’elle dépasse une pression seuil Ps. Cela est la conséquence de la montée de température dans l’accumulateur 3. La pression seuil Ps est par exemple comprise entre 13 et 15 bars. La pression seuil Ps est notamment comprise entre 13 et 15 bars pour des formats d’accumulateurs cylindriques 18650. [0071] The accumulator 3 is overpressurized when it exceeds a threshold pressure Ps. This is the consequence of the temperature rise in the accumulator 3. The threshold pressure Ps is for example between 13 and 15 bars. The threshold pressure Ps is in particular between 13 and 15 bars for cylindrical 18650 accumulator formats.

[0072] On entend par température d’emballement thermique Te un seuil de température au-delà duquel la température à l’intérieur de l’accumulateur monte de manière incontrôlée. Ce seuil est atteint lorsque la réaction exothermique qui survient suite à un défaut ou un usage abusif de l’accumulateur ne peut pas être refroidi. Dans ce cas, la température continue à monter s’auto-alimentant par cette montée en température, et l’accumulateur défectueux rentre dans un procédé de rétroaction positive. [0072] Thermal runaway temperature Te is understood to mean a temperature threshold beyond which the temperature inside the accumulator rises in an uncontrolled manner. This threshold is reached when the exothermic reaction that occurs following a defect or abusive use of the accumulator cannot be cooled. In this case, the temperature continues to rise, self-feeding itself by this rise in temperature, and the defective accumulator enters a positive feedback process.

[0073] La température d’emballement thermique Te dépend notamment des composants de l’accumulateur 3 et aussi de son état de charge (SoC pour "State of Charge”) de l’accumulateur 3. La température d’emballement thermique Te est révélée en mesurant la température de la peau de l’accumulateur 3. L’accumulateur 3 est considéré parti en emballement thermique lorsque la température de peau Tp de l’accumulateur 3, c’est-à-dire la température prise sur une surface externe des parois 301 , 302 de l’enveloppe, atteint une plage de température comprise entre 70°C et 120°C. Les températures des gaz générés par l’emballement thermique au cœur de l’accumulateur peuvent excéder les 800°C voire les 1000°C. [0073] The thermal runaway temperature Te depends in particular on the components of the accumulator 3 and also on its state of charge (SoC for “State of Charge”) of the accumulator 3. The thermal runaway temperature Te is revealed by measuring the temperature of the skin of the accumulator 3. The accumulator 3 is considered to have gone into thermal runaway when the skin temperature Tp of the accumulator 3, i.e. the temperature taken on an external surface of the walls 301, 302 of the casing, reaches a temperature range of between 70°C and 120°C. The temperatures of the gases generated by the thermal runaway at the core of the accumulator can exceed 800°C or even 1000°C.

[0074] Lors d’une surpression dans l’accumulateur 3 causée par un emballement thermique, l’enveloppe 300 de l’accumulateur 3 se déforme. La pression monte au sein de l’accumulateur 3 déformant l’enveloppe 300 et allant jusqu’à l’ouverture de la zone fragilisée 307. [0074] During an overpressure in the accumulator 3 caused by thermal runaway, the casing 300 of the accumulator 3 deforms. The pressure rises within the accumulator 3, deforming the casing 300 and going as far as opening the weakened zone 307.

[0075] Les gaz générés au sein de l’accumulateur 3 par la réaction exothermique sont libérés par l’ouverture de la zone fragilisée 307, le seuil de pression Ps étant atteint. Suivant l’importance de la réaction, l’ouverture de l’enveloppe peut s’effectuer aussi à d’autres endroits sur l’enveloppe 300 ; produisant une ouverture de l’enveloppe par laquelle les gaz s’échappent. [0075] The gases generated within the accumulator 3 by the exothermic reaction are released by the opening of the weakened zone 307, the pressure threshold Ps being reached. Depending on the importance of the reaction, the opening of the envelope can also be carried out at other locations on the envelope 300; producing an opening of the envelope through which the gases escape.

[0076] Les gaz évacués au moins en partie de l’accumulateur par la zone fragilisée 307 sont à minima à la température d’emballement thermique voire à une température supérieure. Les gaz se retrouvent en contact du fluide caloporteur 5 qui change de phase absorbant ainsi les calories évacuées par ces gaz chauds. Le fluide caloporteur 5 contient ainsi localement la température. Le fluide caloporteur 5 rentre en contact avec les gaz produits par l’accumulateur 3 à l’extérieur et/ou à l’intérieur de l’accumulateur. Le fluide caloporteur peut entrer en contact avec les gaz évacués par la zone fragilisée. Le fluide caloporteur 5 peut aussi entrer en contact avec les gaz à l’intérieur de l’accumulateur 3. Le fluide caloporteur 5 rentre par la zone fragilisée 307 de l’enveloppe 300 de l’accumulateur 3 et se diffuse à l’intérieur se mélangeant à l’électrolyte et s’approchant de l’origine du départ de l’emballement thermique. Le fluide caloporteur 5 entre en contact avec le cœur de l’accumulateur 3. Le fluide caloporteur 5 rentrant migre vers le cœur de l’accumulateur 3 et donc auprès du point central d’échauffement pour l’étouffer. Cela permet d’éviter que l’emballement thermique continue de progresser tant à l’intérieur de l’accumulateur 3 qu’à l’extérieur de l’accumulateur 3. Cela permet également d’éviter la propagation de l’emballement thermique aux accumulateurs 3 voisins. Il est ainsi possible de circonscrire la source du défaut. [0076] The gases evacuated at least in part from the accumulator by the weakened zone 307 are at least at the thermal runaway temperature or even at a higher temperature. The gases come into contact with the heat transfer fluid 5 which changes phase, thus absorbing the calories evacuated by these hot gases. The heat transfer fluid 5 thus locally contains the temperature. The heat transfer fluid 5 comes into contact with the gases produced by the accumulator 3 outside and/or inside the accumulator. The heat transfer fluid can come into contact with the gases evacuated by the weakened zone. The heat transfer fluid 5 can also come into contact with the gases inside the accumulator 3. The heat transfer fluid 5 enters through the weakened zone 307 of the casing 300 of the accumulator 3 and diffuses inside, mixing with the electrolyte and approaching the origin of the start of the thermal runaway. The heat transfer fluid 5 comes into contact with the core of the accumulator 3. The returning heat transfer fluid 5 migrates towards the core of the accumulator 3 and therefore near the central heating point to smother it. This prevents the thermal runaway from continuing to progress both inside the accumulator 3 and outside the accumulator 3. This also prevents the thermal runaway from spreading to neighboring accumulators 3. It is thus possible to circumscribe the source of the fault.

[0077] Autrement dit, la présente invention profite de la propriété de la chaleur latente de vaporisation du fluide caloporteur 5 pour contenir l’emballement thermique de l’accumulateur défectueuse au sein de l’accumulateur lorsque cette dernière s’ouvre lors d’un emballement thermique. Le fluide caloporteur 5 rentre dans l’accumulateur 3 et se dilhue dans le liquide de l’électrolyte de l’accumulateur 3 accédant progressivement au contact de la zone où s’est produit réchauffement thermique. En d’autres termes encore, le fluide caloporteur 5 pénètre dans l’accumulateur 3 contribuant à accéder au plus près de réchauffement qui s’est créé dans l’accumulateur 3. Cela permet d’agir au plus près du défaut et ainsi d’étouffer réchauffement. [0077] In other words, the present invention takes advantage of the property of the latent heat of vaporization of the heat transfer fluid 5 to contain the thermal runaway of the defective accumulator within the accumulator when the latter opens during a thermal runaway. The heat transfer fluid 5 enters the accumulator 3 and dilutes in the liquid of the electrolyte of the accumulator 3 gradually reaching the contact of the zone where thermal heating has occurred. In other words again, the heat transfer fluid 5 enters the accumulator 3 contributing to reaching as close as possible to the heating that has been created in the accumulator 3. This makes it possible to act as close as possible to the defect and thus to stifle the heating.

[0078] Le fluide caloporteur 5, au contact des gaz chauds sortant de l’accumulateur 3, passe d’un état liquide à un état gazeux. [0078] The heat transfer fluid 5, in contact with the hot gases leaving the accumulator 3, passes from a liquid state to a gaseous state.

[0079] Le fluide caloporteur 5 a une température de changement d’état liquide/gazeux Te. De préférence, le fluide caloporteur 5 a une température de changement d’état liquide/gaz Te supérieure à la température de peau Tp de l’enveloppe. Ainsi, lors d’un emballement thermique, le fluide caloporteur 5 autour de l’accumulateur 3 reste liquide. Un échange thermique se fait alors avec les parois 301 , 302 de l’accumulateur 3. [0079] The heat transfer fluid 5 has a liquid/gaseous state change temperature Te. Preferably, the heat transfer fluid 5 has a liquid/gaseous state change temperature Te higher than the skin temperature Tp of the envelope. Thus, during thermal runaway, the heat transfer fluid 5 around the accumulator 3 remains liquid. A heat exchange then takes place with the walls 301, 302 of the accumulator 3.

[0080] La température de changement d’état liquide/gaz Te est supérieure à la température de peau Tp de l’enveloppe lorsque la zone fragilisée 307 est ouverte. Par exemple, l’emballement thermique génère une montée de la température interne telle que la température de peau Tp de l’accumulateur atteigne une température comprise entre 70°C et 120°C et telle que cette montée de température provoque aussi l’ouverture de la zone fragilisée 307 libérant des gaz chauds. La température de changement d’état liquide/gaz Te est choisie de manière à changer de phase lorsque le fluide caloporteur est en contact avec les gaz chauds. Ce changement de phase peut opérer entre 80°C et 250°C suivant le choix du fluide caloporteur. La température ou seuil de changement d’état liquide/gazeux Te du fluide caloporteur 5 est ainsi défini par rapport au seuil de température de peau Tp lorsque l’emballement thermique génère l’ouverture de la zone fragilisée 307. Cela permet de disposer du changement de phase du fluide caloporteur au moment où les gaz chauds sortent de l’accumulateur. Les températures des gaz chauds sortant de l’accumulateur étant liées aux composants chimiques constituant l’accumulateur et aussi à l’énergie stockée dans l’accumulateur au moment de l’emballement thermique, elles s’étendent de 70°C au début de l’emballement et montent très vite vers les 400°C pour atteindre les 1000°C si aucune disposition n’est prise pour contenir la réaction. A noter que l’enveloppe 300 s’ouvre nécessairement au niveau de la zone fragilisée 307, celle-ci étant tarée pour une telle ouverture lors d’une surpression. Il est possible que l’enveloppe 300 s’ouvre également à d’autres endroits, en fonction notamment de l’intensité de la réaction au sein de l’accumulateur 3, permettant à ces endroits également le contact du fluide caloporteur 5 avec les gaz évacués. [0080] The liquid/gas state change temperature Te is higher than the skin temperature Tp of the casing when the weakened zone 307 is open. For example, thermal runaway generates a rise in the internal temperature such that the skin temperature Tp of the accumulator reaches a temperature between 70°C and 120°C and such that this rise in temperature also causes the weakened zone 307 to open, releasing hot gases. The liquid/gas state change temperature Te is chosen so as to change phase when the heat transfer fluid is in contact with the hot gases. This change of phase can operate between 80°C and 250°C depending on the choice of the heat transfer fluid. The liquid/gaseous state change temperature or threshold Te of the heat transfer fluid 5 is thus defined in relation to the skin temperature threshold Tp when the thermal runaway generates the opening of the weakened zone 307. This makes it possible to have the phase change of the heat transfer fluid at the moment when the hot gases leave the accumulator. The temperatures of the hot gases leaving the accumulator being linked to the chemical components constituting the accumulator and also to the energy stored in the accumulator at the time of the thermal runaway, they extend from 70°C at the start of the runaway and rise very quickly towards 400°C to reach 1000°C if no measures are taken to contain the reaction. It should be noted that the casing 300 necessarily opens at the weakened zone 307, the latter being calibrated for such an opening during an overpressure. It is possible that the casing 300 also opens at other locations, depending in particular on the intensity of the reaction within the accumulator 3, allowing at these locations also the contact of the heat transfer fluid 5 with the evacuated gases.

[0081] Le fluide caloporteur 5 rentré accède au point chaud et s’évapore au contact des parties chaudes et limite la montée de température. Le fluide caloporteur 5 joue le rôle d’extracteur de calories. Le fluide caloporteur 5 évite que le reste de la matière de l’accumulateur 3 défectueuse participe à l’emballement thermique. Le fluide caloporteur 5 stabilise puis stoppe l’emballement thermique au sein de la l’accumulateur 3. Ainsi, en contenant l’emballement thermique à la source, cette solution évite la propagation de cet emballement thermique aux accumulateurs 3 adjacentes. [0081] The returned heat transfer fluid 5 reaches the hot point and evaporates on contact with the hot parts and limits the temperature rise. The heat transfer fluid 5 acts as a heat extractor. The heat transfer fluid 5 prevents the remainder of the defective material of the accumulator 3 from contributing to the thermal runaway. The heat transfer fluid 5 stabilizes and then stops the thermal runaway within the accumulator 3. Thus, by containing the thermal runaway at the source, this solution prevents the propagation of this thermal runaway to the adjacent accumulators 3.

[0082] Les propriétés du fluide caloporteur 5 sont adaptées au besoin des accumulateurs 3 pour contenir leur emballement thermique pour la température de changement d’état liquide/gazeux Te. Suivant les chimies des accumulateurs et de l’énergie stockée au moment de l’emballement thermique, le seuil d’emballement thermique Te est différent. En conséquence, la formulation du fluide caloporteur 5 est à adapter pour disposer d’un seuil de changement de phase liquide/gazeux Te compatible du seuil d’emballement thermique Te. [0082] The properties of the heat transfer fluid 5 are adapted to the needs of the accumulators 3 to contain their thermal runaway for the liquid/gaseous state change temperature Te. Depending on the chemistries of the accumulators and the energy stored at the time of thermal runaway, the thermal runaway threshold Te is different. Consequently, the formulation of the heat transfer fluid 5 must be adapted to have a liquid/gaseous phase change threshold Te compatible with the thermal runaway threshold Te.

[0083] La viscosité du fluide caloporteur 5 peut être choisie de manière à permettre au fluide caloporteur 5 d’intégrer l’accumulateur 3 lorsque la zone fragilisée 307 de l’enveloppe 300 s’ouvre. En cas d’ouverture également à d’autres endroits de l’enveloppe 300 autres que la zone fragilisée 307, la viscosité du fluide caloporteur 5 facilite également bien entendu la pénétration du fluide caloporteur dans l’accumulateur 3. Il est à noter que le fluide caloporteur 5 passant à l’état gazeux au contact avec les gaz produits par l’accumulateur 3, gagne en viscosité lorsque la température augmente. Cela facilite d’autant plus la pénétration du fluide caloporteur 5 au sein de l’accumulateur 3. [0083] The viscosity of the heat transfer fluid 5 can be chosen so as to allow the heat transfer fluid 5 to integrate the accumulator 3 when the weakened zone 307 of the casing 300 opens. In the event of opening also at other locations of the envelope 300 other than the weakened zone 307, the viscosity of the heat transfer fluid 5 also of course facilitates the penetration of the heat transfer fluid into the accumulator 3. It should be noted that the heat transfer fluid 5 passing into the gaseous state on contact with the gases produced by the accumulator 3, gains in viscosity when the temperature increases. This further facilitates the penetration of the heat transfer fluid 5 into the accumulator 3.

[0084] Par ailleurs, lorsque le fluide caloporteur 5 est une huile synthétique, cela permet de bénéficier d’un meilleur refroidissement des accumulateurs 3 dans les conditions nominales de fonctionnement, car l’huile se répand dans tout le boîtier 2 et assure un contact uniforme sur toutes les parois des accumulateurs 3 et donc un bon échange thermique. L’huile avec ses propriétés intrinsèques de rigidité diélectrique permet également de faciliter l’intégration de batterie haute tension en réduisant les distances d’isolement des pièces portées aux hautes tensions et éviter les risques de claquage entre les pièces portées à la haute tension et les parois du boîtier 2 du pack-batterie dans lesquelles les accumulateurs 3 élémentaires sont intégrées et ou d’un boîtier du module dans le cas d’une intégration dans le pack- batterie avec des modules. [0084] Furthermore, when the heat transfer fluid 5 is a synthetic oil, this makes it possible to benefit from better cooling of the accumulators 3 under nominal operating conditions, because the oil spreads throughout the housing 2 and ensures uniform contact on all the walls of the accumulators 3 and therefore good heat exchange. The oil with its intrinsic dielectric strength properties also makes it possible to facilitate the integration of high-voltage batteries by reducing the insulation distances of the parts carried at high voltages and avoiding the risks of breakdown between the parts carried at high voltage and the walls of the housing 2 of the battery pack in which the elementary accumulators 3 are integrated and or of a housing of the module in the case of integration into the battery pack with modules.

[0085] Selon un exemple illustratif, la température d’emballement thermique Te commence entre 70°C et 120°C et augmente pour atteindre des températures de l’ordre de 400 à 800 °C voire 1000°C. La température extérieure Tp de l’enveloppe 300 est comprise entre 70°C et 120°C suivant la composition des accumulateurs et l’état de charge de l’accumulateur au moment de l’emballement thermique. Dans ces conditions, le fluide caloporteur 5 est choisi de sorte à avoir une température de changement d’état liquid/gazeux Te supérieure la température extérieure Tp de l’enveloppe 300, par exemple de l’ordre de 130° C. [0085] According to an illustrative example, the thermal runaway temperature Te begins between 70°C and 120°C and increases to reach temperatures of the order of 400 to 800°C or even 1000°C. The external temperature Tp of the casing 300 is between 70°C and 120°C depending on the composition of the accumulators and the state of charge of the accumulator at the time of thermal runaway. Under these conditions, the heat transfer fluid 5 is chosen so as to have a liquid/gaseous state change temperature Te higher than the external temperature Tp of the casing 300, for example of the order of 130°C.

[0086] De préférence, les accumulateurs 3 sont séparés les uns des autres par une distance au moins égale à 1 mm. Cela permet au fluide caloporteur 5 de refroidir efficacement les accumulateurs 3. [0086] Preferably, the accumulators 3 are separated from each other by a distance at least equal to 1 mm. This allows the heat transfer fluid 5 to effectively cool the accumulators 3.

[0087] Le pack-batterie 1 peut en outre comporter une vessie 6 assemblée au boitier 2 (visible dans l’exemple de réalisation illustré aux figures 5 et 6). La vessie 6 est configurée pour absorber des variations de pression dans le boîtier. La vessie 6 peut être élastique et gonflable. [0088] La vessie 6 compense dans un premier temps la surpression produite lors du défaut d’un accumulateur 3 et évite de faire supporter cette surpression aux parois du boîtier 2 du pack-batterie 1 . [0087] The battery pack 1 may further comprise a bladder 6 assembled to the housing 2 (visible in the exemplary embodiment illustrated in FIGS. 5 and 6). The bladder 6 is configured to absorb pressure variations in the housing. The bladder 6 may be elastic and inflatable. [0088] The bladder 6 initially compensates for the excess pressure produced during the failure of an accumulator 3 and prevents the walls of the housing 2 of the battery pack 1 from being subjected to this excess pressure.

[0089] La vessie peut également compenser les variations de pressions liées à la dilatation du fluide caloporteur suivant les conditions environnementales (température, altitude). [0089] The bladder can also compensate for pressure variations linked to the expansion of the heat transfer fluid depending on environmental conditions (temperature, altitude).

[0090] La vessie peut être réalisée en aluminium. [0090] The bladder can be made of aluminum.

[0091] Une vessie ou plusieurs vessies peuvent être disposées au besoin. Par exemple, des vessies peuvent être positionnées au niveau des modules ou au niveau du pack-batterie. [0091] One or more bladders may be arranged as needed. For example, bladders may be positioned at the modules or at the battery pack.

[0092] Le pack-batterie 1 peut comporter en outre un capteur de pression (non représenté). Le capteur de pression est configuré pour mesurer une pression dans le boîtier 2 et/ou pour détecteur une surpression dans le boîtier. [0092] The battery pack 1 may further comprise a pressure sensor (not shown). The pressure sensor is configured to measure a pressure in the housing 2 and/or to detect an overpressure in the housing.

[0093] Le capteur de pression peut être intégré à la vessie 6. [0093] The pressure sensor can be integrated into the bladder 6.

[0094] Dans un autre exemple, le capteur de pression peut être monté sur une paroi interne du boîtier 2. [0094] In another example, the pressure sensor may be mounted on an internal wall of the housing 2.

[0095] Le capteur de pression est configuré pour générer par le biais d’un contacteur, un signal électrique correspondant à une information représentative de ladite pression. [0095] The pressure sensor is configured to generate, via a contactor, an electrical signal corresponding to information representative of said pressure.

[0096] Le capteur de pression peut être configuré pour envoyer un signal d’avertissement en cas de surpression dans le boîtier. [0096] The pressure sensor can be configured to send a warning signal in the event of overpressure in the housing.

[0097] Le capteur de pression peut également être configuré pour donner un ordre d’isolement du pack-batterie en ouvrant un contacteur en sortie du pack-batterie 1 . [0097] The pressure sensor can also be configured to give an order to isolate the battery pack by opening a contactor at the output of the battery pack 1.

[0098] Le capteur de présence de fluide caloporteur est présent dans le pack batterie 1 (non représenté). Il est configuré pour détecter une fuite du liquide caloporteur. [0098] The heat transfer fluid presence sensor is present in the battery pack 1 (not shown). It is configured to detect a leak of the heat transfer fluid.

[0099] Lorsqu’un emballement thermique survient, celui-ci n’est pas nécessairement détecté électriquement, Les modules peuvent continuer à fonctionner étant donné le grand nombre des accumulateurs. Le capteur de pression permet donc de détecter une surpression le plus tôt possible. Lorsque le fluide caloporteur 5 se vaporise, la pression monte, celle-ci est détectée par le capteur de pression qui peut ouvrir le contacteur en sortie du pack-batterie 1 . [0099] When a thermal runaway occurs, it is not necessarily detected electrically. The modules can continue to operate given the large number of accumulators. The pressure sensor therefore makes it possible to detect an overpressure as early as possible. When the heat transfer fluid 5 vaporizes, the pressure rises, this is detected by the pressure sensor which can open the switch at the output of battery pack 1.

[0100] Le boîtier peut en outre comprendre un clapet 7 (visible en figures 5 et 6) configuré pour s’ouvrir lors d’une surpression dans le pack batterie 1 et/ou dans le boîtier 2 d’un des modules. [0100] The housing may further comprise a valve 7 (visible in FIGS. 5 and 6) configured to open in the event of excess pressure in the battery pack 1 and/or in the housing 2 of one of the modules.

[0101] Le clapet 7 comprend par exemple des conduits permettant aux fumées de s’échapper vers l’extérieur du boîtier 2 en cas de dysfonctionnement du pack-batterie 1. [0101] The valve 7 comprises, for example, conduits allowing fumes to escape to the outside of the housing 2 in the event of a malfunction of the battery pack 1.

[0102] Le clapet 7 permet en outre d’évacuer les fumées du fluide caloporteur en cas de dégagement gazeux d’un accumulateur 3 ou de plusieurs accumulateurs 3 qui pourraient partir en emballement thermique simultanément. [0102] The valve 7 also makes it possible to evacuate fumes from the heat transfer fluid in the event of gas being released from an accumulator 3 or from several accumulators 3 which could go into thermal runaway simultaneously.

[0103] Bien entendu, la présente invention n'est pas limitée aux modes de réalisation décrits et illustrés. [0103] Of course, the present invention is not limited to the embodiments described and illustrated.

[0104] Par exemple, dans le cas où un boîtier loge un ensemble de modules, le fluide caloporteur peut être également contenu dans ledit boîtier. [0104] For example, in the case where a housing houses a set of modules, the heat transfer fluid can also be contained in said housing.

[0105] Grâce à l’invention, il est obtenu une diminution du risque voire une absence de départ de feu lorsque l’accumulateur part en emballement thermique. Les propriétés du fluide caloporteur facilitent les échanges thermiques de l’accumulateur avec l’extérieur en rentrant en ébullition au plus près du seuil de déclenchement de l’accumulateur en emballement thermique. Cette mise en ébullition et l’infiltration du fluide caloporteur par la zone fragilisée de l’enveloppe de l’accumulateur partie en emballement aident à contenir l’emballement et réduisent les projections de flamme et de fumée chaude qui peuvent s’extraire de l’accumulateur lors de tels défauts. En outre, le fluide caloporteur absorbe la surpression générée lors de l’explosion de l’accumulateur, réduisant ainsi les contraintes mécaniques dans l’enveloppe et le boîtier du pack-batterie. [0105] Thanks to the invention, a reduction in the risk or even an absence of fire is obtained when the accumulator goes into thermal runaway. The properties of the heat transfer fluid facilitate the heat exchanges of the accumulator with the outside by boiling as close as possible to the threshold for triggering the accumulator in thermal runaway. This boiling and the infiltration of the heat transfer fluid through the weakened zone of the casing of the accumulator that is going into runaway help to contain the runaway and reduce the projections of flame and hot smoke that can be extracted from the accumulator during such defects. In addition, the heat transfer fluid absorbs the excess pressure generated during the explosion of the accumulator, thus reducing the mechanical stresses in the casing and the housing of the battery pack.

[0106] Grâce au refroidissement de composants par le fluide caloporteur, l’invention permet de refroidir les accumulateurs dans le mode de fonctionnement nominale et d’améliorer indirectement la fiabilité des accumulateurs. [0106] Thanks to the cooling of components by the heat transfer fluid, the invention makes it possible to cool the accumulators in the nominal operating mode and to indirectly improve the reliability of the accumulators.

[0107] Il est également obtenu la diminution du risque voire l’arrêt de la propagation d’un emballement thermique aux accumulateurs adjacents. [0108] La solution grâce à la mise en contact direct du fluide caloporteur avec l’accumulateur qui part en emballement thermique permet d’enclencher le changement de phase du fluide caloporteur absorbant l’énergie évacuée par l’accumulateur défectueux et contribuant à contenir l’emballement thermique. [0107] It is also achieved the reduction of the risk or even the stopping of the propagation of a thermal runaway to adjacent accumulators. [0108] The solution, by putting the heat transfer fluid in direct contact with the accumulator which is going into thermal runaway, makes it possible to initiate the phase change of the heat transfer fluid absorbing the energy evacuated by the defective accumulator and helping to contain the thermal runaway.

[0109] Grâce à l’usage d’un fluide caloporteur tel que des huiles synthétiques ininflammables, ces fluides présentes des propriétés diélectriques qui contribuent à réduire les risques d’arc électrique pour les batteries haute tension. [0109] Through the use of a heat transfer fluid such as non-flammable synthetic oils, these fluids have dielectric properties which help to reduce the risks of electric arcing for high voltage batteries.

[0110] L’invention bénéficie à tout type de batterie sujettes à des emballements thermiques, notamment dans des cas d’usages extrêmes tels que les cas listés ci- après mais non limité à des chocs, des court-circuits interne et externe et des conditions de température abusives. [0110] The invention benefits any type of battery subject to thermal runaway, particularly in cases of extreme use such as the cases listed below but not limited to shocks, internal and external short circuits and abusive temperature conditions.

Claims

REVENDICATIONS 1 . Batterie comportant : au moins un accumulateur (3) électrochimique comprenant une partie active et une enveloppe renfermant ladite partie active ; un boîtier (2) logeant ledit au moins un accumulateur (3) ; et un fluide caloporteur (5) contenu dans le boîtier (2), l’enveloppe (300) comprenant une zone fragilisée (307) configurée pour s’ouvrir sous l’effet d’une surpression dans l’accumulateur (3) et pour évacuer des gaz produits par la partie active de l’accumulateur (3) à l’origine de la surpression, dans laquelle, lors de la surpression dans ledit au moins un accumulateur (3), ledit fluide caloporteur (5) entre en contact avec les gaz produits par l’accumulateur (3) de sorte à contenir lesdits gaz et refroidir l’accumulateur, et dans laquelle au contact avec les gaz produits par l’accumulateur (3), le fluide caloporteur (5) passe d’un état liquide à un état gazeux. 1. Battery comprising: at least one electrochemical accumulator (3) comprising an active part and an envelope enclosing said active part; a housing (2) housing said at least one accumulator (3); and a heat transfer fluid (5) contained in the housing (2), the envelope (300) comprising a weakened zone (307) configured to open under the effect of an overpressure in the accumulator (3) and to evacuate gases produced by the active part of the accumulator (3) at the origin of the overpressure, in which, during the overpressure in said at least one accumulator (3), said heat transfer fluid (5) comes into contact with the gases produced by the accumulator (3) so as to contain said gases and cool the accumulator, and in which upon contact with the gases produced by the accumulator (3), the heat transfer fluid (5) changes from a liquid state to a gaseous state. 2. Batterie selon la revendication 1 , dans laquelle lors d’une surpression dans ledit au moins un accumulateur (3), ledit fluide caloporteur (5) pénètre par la zone fragilisée (307) ouverte de sorte à contenir au moins une partie des gaz produits par l’accumulateur (3). 2. Battery according to claim 1, in which during an overpressure in said at least one accumulator (3), said heat transfer fluid (5) penetrates through the open weakened zone (307) so as to contain at least part of the gases produced by the accumulator (3). 3. Batterie selon la revendication 1 ou la revendication 2, dans laquelle lors d’une surpression dans ledit au moins un accumulateur (3), ledit fluide caloporteur (5) entre en contact, à l’extérieur de l’accumulateur (3), avec au moins une partie des gaz évacués. 3. Battery according to claim 1 or claim 2, in which during an overpressure in said at least one accumulator (3), said heat transfer fluid (5) comes into contact, outside the accumulator (3), with at least part of the evacuated gases. 4. Batterie selon l’une des revendications 1 à 3, dans laquelle le fluide caloporteur (5) a une température de changement d’état liquide/gazeux (Te) supérieure à une température de peau (Tp) lors d’un emballement thermique à l’origine de l’ouverture de la zone fragilisée (307) dudit au moins un accumulateur (3) électrochimique. 4. Battery according to one of claims 1 to 3, in which the heat transfer fluid (5) has a liquid/gaseous state change temperature (Te) higher than a skin temperature (Tp) during thermal runaway causing the opening of the weakened zone (307) of said at least one electrochemical accumulator (3). 5. Batterie selon l’une des revendications 1 à 4, dans laquelle l’enveloppe (300) comprend une faiblesse structurelle formant la zone fragilisée (307), la zone fragilisée étant configurée pour s’ouvrir par rupture sous l’effet de la surpression dans l’accumulateur (3). 5. Battery according to one of claims 1 to 4, in which the envelope (300) comprises a structural weakness forming the weakened zone (307), the weakened zone being configured to open by rupture under the effect of the overpressure in the accumulator (3). 6. Batterie selon l’une des revendications 1 à 5, dans laquelle le fluide caloporteur (5) est une huile ininflammable. 6. Battery according to one of claims 1 to 5, in which the heat transfer fluid (5) is a non-flammable oil. 7. Batterie selon l’une des revendications 1 à 6, dans laquelle le fluide caloporteur (5) a une viscosité comprise entre 0,3 mm2.s et 5 mm2.s, de préférence entre 1 mm2.s et 5 mm2.s. 7. Battery according to one of claims 1 to 6, in which the heat transfer fluid (5) has a viscosity of between 0.3 mm 2 .s and 5 mm 2 .s, preferably between 1 mm 2 .s and 5 mm 2 .s. 8. Batterie selon l’une des revendications 1 à 7, comportant en outre une vessie (6) assemblée au boitier (2) et configurée pour absorber des variations de pression dans le boîtier (2). 8. Battery according to one of claims 1 to 7, further comprising a bladder (6) assembled to the housing (2) and configured to absorb pressure variations in the housing (2). 9. Batterie selon l’une des revendications 1 à 8, comportant en outre un capteur de pression configuré pour détecter une surpression dans le boîtier (2). 9. Battery according to one of claims 1 to 8, further comprising a pressure sensor configured to detect excess pressure in the housing (2). 10. Batterie selon l’une des revendications 1 à 9, dans laquelle le boîtier (2) comprend un clapet (7) configuré pour s’ouvrir lors d’une surpression dans le boîtier (2) et/ou dans ledit au moins un accumulateur (3). 10. Battery according to one of claims 1 to 9, in which the housing (2) comprises a valve (7) configured to open during an overpressure in the housing (2) and/or in said at least one accumulator (3). 11. Batterie selon l’une des revendications 1 à 10, dans laquelle le boîtier (2) comprend un capteur de présence d’huile configuré pour détecter une fuite du liquide caloporteur dans le boîtier (2). 11. Battery according to one of claims 1 to 10, in which the housing (2) comprises an oil presence sensor configured to detect a leak of the heat transfer liquid in the housing (2). 12. Batterie selon l’une des revendications 1 à 11 , comportant plusieurs accumulateurs (3) et plusieurs enveloppes (300), les accumulateurs (3) étant agencés en série ou en parallèle dans le boîtier (2), chaque enveloppe (300) renfermant l’un des accumulateurs (3). 12. Battery according to one of claims 1 to 11, comprising several accumulators (3) and several envelopes (300), the accumulators (3) being arranged in series or in parallel in the housing (2), each envelope (300) enclosing one of the accumulators (3).
PCT/EP2024/066181 2023-06-14 2024-06-12 Battery pack comprising a heat-transfer fluid capable of containing the thermal runaway of the electrochemical accumulators of the battery pack Ceased WO2024256441A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP24732906.3A EP4728584A1 (en) 2023-06-14 2024-06-12 Battery pack comprising a heat-transfer fluid capable of containing the thermal runaway of the electrochemical accumulators of the battery pack
CN202480039425.5A CN121548892A (en) 2023-06-14 2024-06-12 The battery pack includes heat transfer fluids that can limit the thermal runaway of the electrochemical batteries.

Applications Claiming Priority (2)

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FRFR2306054 2023-06-14
FR2306054A FR3150046A1 (en) 2023-06-14 2023-06-14 Battery pack comprising a heat transfer fluid capable of containing the thermal runaway of the electrochemical accumulators of the battery pack

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EP4728584A1 (en) 2026-04-22
FR3150046A1 (en) 2024-12-20

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