Battery thermal management and safety method and device for implementing same

Abstract

The invention relates to a thermal management and safety method for a battery in an apparatus comprising a battery comprising a plurality of modules, each module comprising a plurality of battery cells, and a cooling circuit comprising a loop for circulating a coolant and a control valve for controlling the coolant flow upstream of each module, the method comprises the following steps: a) a step of detecting a fault in at least one battery cell of the module, b) a step of regulating the flow when a fault is detected, the step comprising increasing the flow of coolant in the module comprising the at least one faulty battery cell.

Description

Technical Field

[0001] The invention relates to thermal management and safety of a battery comprising several battery cells, in particular for mobile or stationary applications. Prior art

[0002] A battery is a system for generating electricity in which chemical energy is converted into electrical energy. The chemical energy comprises electrochemically active compounds deposited on at least one side of an electrode arranged in an electrochemical generator. Electrical energy is generated by electrochemical reactions during discharge of an electrochemical cell.

[0003] A battery comprises a plurality of electrochemical cells. Lithium-ion electrochemical cells are based on the principle of reversible insertion of lithium into a host structure in an electrochemically active manner.

[0004] In the field of electrochemical cells, such as lithium-ion cells, the temperature of the cell must be regulated in order to maintain the temperature within an appropriate range for the cell.

[0005] Lithium-ion batteries are typically used in a temperature range of 0 to 40° C. In a runaway situation, some battery cells may reach temperatures of the order of 400 to 800° C.

[0006] Batteries are often used in mobile or stationary applications.

[0007] Stationary applications include batteries used to store energy, such as solar energy storage batteries, and energy storage systems.

[0008] Mobile applications include motorized applications such as electric vehicles or aircraft.

[0009] Batteries can generate a lot of heat, especially during rapid charging. It is therefore necessary to be able to remove this heat. To cool the batteries, air and water (if appropriate) in combination with antifreeze are known. However, with increasingly complex batteries and heat-generating systems, cooling methods are not always sufficient.

[0010] Furthermore, in battery systems comprising a plurality of cells, a proven risk is the propagation of faults that may occur on one or more electrochemical cells that are part of a battery, which typically comprises 100 to 10,000 cells. These faults may have various causes (short circuits, high temperatures (e.g. >150°C), loss of integrity of the cell during an accident, etc.) and lead to a sharp increase in the temperature of the cell associated with a hot gas jet (up to 800°C or even higher). The safety system is obviously intended to prevent such potential faults. In such a framework, it is appropriate to consider the circumstances in which the fault occurs. The safety system will be committed to preventing the propagation of thermal runaway. In fact, the intense heat generated by a faulty cell can become a source of thermal runaway for adjacent cells.

[0011] Document EP 2873541 discloses a cooling system for hybrid or electric vehicle batteries, comprising a circulation of a heat transfer coolant in a main loop and branches controlled according to the temperature of a heat transfer fluid. The document describes a relatively complex system involving branch circuits. The document does not solve the same problem as the present invention.

[0012] Document WO 2021 / 062305 discloses a thermal management technology for a passenger compartment of a vehicle. The document is not directed to thermal management and safety systems for batteries, and the document proposes circulating coolant when the system exceeds a certain threshold.

[0013] Document EP 4027435 describes preventing the spread of fire in the battery by circulating a coolant when the system exceeds a certain threshold.

[0014] The subject of the present invention is therefore to propose a new, easily implementable thermal management and battery safety system aimed at preventing the propagation of thermal runaway of a faulty battery. Summary of the invention

[0015] More precisely, the present invention relates to a method for thermal management and safety of a battery in a device, the device comprising a battery and a cooling circuit, the battery comprising a plurality of modules, each module comprising a plurality of battery cells, and the cooling circuit comprising a circulation loop for a coolant and a regulating valve for regulating the flow of the coolant upstream of each module, the method comprising the following steps:

[0016] a) a step of detecting a fault in at least one battery cell of the module,

[0017] b) When a fault is detected, a flow regulating step includes increasing the coolant flow through the module(s) containing at least one faulty battery cell.

[0018] According to one embodiment, at least 50% of the coolant flow is redirected to one or more modules including at least one faulty battery cell, preferably at least 70% of the flow, more preferably at least 90% of the flow, or even 100% of the coolant flow is redirected to one or more modules including at least one faulty battery cell.

[0019] According to one embodiment, step a) comprises the following consecutive steps:

[0020] a1 sets a threshold value of at least one parameter selected from temperature, voltage and current,

[0021] a2 measuring at least one parameter selected from temperature, voltage and current during battery operation,

[0022] a3 When the measured parameter is above or below the threshold value set during step a1, a fault is detected.

[0023] According to one embodiment, the parameter is the temperature of the coolant, and the method comprises:

[0024] a1 sets the temperature threshold that should not be exceeded.

[0025] a2 measures the coolant temperature at the outlet of each module or at the outlet of each battery cell,

[0026] a3 detecting a fault in at least one given module or cell when the temperature measured at the outlet of said module or cell exceeds a temperature threshold,

[0027] b) redirecting at least a portion of the coolant flow towards the faulty module or the module comprising the faulty battery cell.

[0028] According to one embodiment, the parameter is the temperature of each module or each battery cell, and the method comprises:

[0029] a1 sets the temperature threshold that should not be exceeded for each module or each battery cell.

[0030] a2 measures the temperature of each module of each battery cell,

[0031] a3 when the measured temperature of at least one given module or battery cell exceeds a temperature threshold, a fault in said module or battery cell is detected,

[0032] b) redirecting at least part of the coolant flow to the faulty module or the module comprising the faulty battery cell.

[0033] According to one embodiment, step a) comprises the following consecutive steps:

[0034] a1 sets a threshold value for a change in at least one parameter during a given time period, the at least one parameter being selected from temperature, voltage and current,

[0035] a2 measuring said parameters during battery operation,

[0036] a3 when said threshold is exceeded, a fault is detected in at least one given module or at least one given battery cell,

[0037] According to one embodiment, step b) further comprises reducing the coolant flow in one or more modules without a faulty battery cell.

[0038] According to one embodiment, the regulating step b) is performed until the failed battery cell or cells are restored to normal operation.

[0039] Another subject of the invention is a device for implementing the method according to the invention, comprising:

[0040] - a battery comprising a plurality of modules, each module comprising a plurality of electrochemical cells,

[0041] -Cooling system, including:

[0042] oCirculation loop for coolant,

[0043] oAt least one valve upstream of each module to control the flow of coolant.

[0044] According to one embodiment, the at least one valve is a shut-off valve for stopping the flow circulation in the modules not comprising any faulty battery cells.

[0045] According to one embodiment, the device further comprises a control unit for detecting at least one faulty battery cell.

[0046] According to one embodiment, the device also comprises at least one sensor at the outlet of each module or each battery cell making it possible to measure at least one parameter selected from the temperature and the current of the coolant.

[0047] According to one embodiment, the device further comprises an air conditioning circuit in which the refrigerant fluid flows.

[0048] Preferably, the device comprises a cooling circuit further comprising at least one heat exchanger intended to exchange heat with the air or refrigerant fluid of the air conditioning circuit.

[0049] According to one embodiment, the device comprises a cooling circuit further comprising at least one heat exchanger intended to exchange heat with air.

[0050] The management method of the invention makes it possible to prevent the risk of thermal runaway and to reduce the propagation of thermal runaway very quickly.

[0051] The management method of the present invention is easy to implement and can be implemented in mobile or fixed applications.

[0052] The management method of the invention does not require any external coolant supply, but instead uses the coolant already present in the circuit to cool the battery in order to prevent the propagation of thermal runaway.

[0053] Therefore, the method of the present invention can be used in batteries for storing energy, such as solar batteries, and in energy storage systems.

[0054] Thus, the method of the invention may be used in electric or hybrid vehicles or aircraft.

[0055] Unless otherwise stated, amounts in the products are expressed by weight relative to the total weight of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] [ Figure 1 ] represents the trend of the oil pump flow under reference conditions.

[0057] [ Figure 2 ] indicates the flow rate of coolant in the out-of-control module and in the parallel modules. –

[0058] [ Figure 3 ] represents the trend of coolant temperature at different positions of the battery under reference condition.

[0059] [ Figure 4 ] represents the temperature trend of the battery cells in the runaway module under the reference condition.

[0060] [ Figure 5 ] shows the trend of flow distribution between the out-of-control module and the parallel modules for different flow regulation levels in the modules.

[0061] [ Figure 6 ] shows the trend of the oil pump flow in the module during runaway for different flow regulation levels in the module.

[0062] [ Figure 7 ] shows the oil temperature trend at the input of the battery pack for different flow regulation levels in the module.

[0063] [ Figure 8 ] shows the oil temperature trend at the outlet of the out-of-control module for different flow regulation levels in the module.

[0064] [ Fig. 9 ] shows the oil temperature trend at the outlet of the battery pack for different flow regulation levels in the module.

[0065] [ Fig.10 ] shows the temperature trends of neighboring battery cells of a battery cell experiencing a runaway condition for different flow regulation levels in a module.

[0066] [ Fig.11 ] shows the temperature trend of the out-of-control battery cell for different flow regulation levels in the module. DETAILED DESCRIPTION

[0067] The invention relates to a method for thermal management and safety of a battery in a device comprising a battery and a cooling circuit.

[0068] According to the invention, the battery comprises a plurality of modules, each module comprising a plurality of electrochemical cells.

[0069] Preferably, the modules of the battery are placed in parallel with each other.

[0070] The thermal and safety management method according to the invention is generally implemented using a cooling circuit comprising a circulation loop for a coolant that is in direct contact with the battery cells.

[0071] Therefore, according to one embodiment, the coolant is in direct contact with the battery cells. In fact, the non-aqueous nature of the coolant makes it possible to operate in direct contact so that cooling and heat transfer are more efficient. On the other hand, aqueous coolants cannot achieve direct contact and are therefore less efficient in cooling and heat transfer.

[0072] By direct contact, according to the present invention, it is understood that the coolant and the battery cell are in contact without any obstacles between them. It optimizes the exchange surface between the coolant and the battery cell and achieves better heat transfer efficiency, thereby preventing or delaying the thermal runaway phenomenon.

[0073] In nominal operation, the coolant circulates at a given flow rate, preferably at the same flow rate in each module of the battery.

[0074] The coolant used according to the invention is preferably a non-aqueous coolant. The coolant used according to the invention advantageously has insulating properties, for example a resistivity at 30° C. measured according to standard ASTM D1169 greater than or equal to 1 Mohm.m, preferably greater than or equal to 100 Mohm.m. Thus, typically, the coolant used according to the invention has a resistivity less than or equal to 10 -6 ohm -1 .m -1 , preferably less than or equal to 10 -8 ohm -1 .m -1This property is particularly advantageous when the coolant is used in direct contact with the battery cells.

[0075] The coolant used according to the present invention comprises one or more base oils, and the base oils are preferably present in an amount of 70 to 100% by weight, preferably in an amount of 70 to 99% by weight, more preferably in an amount of 80 to 98% by weight, and even more preferably in an amount of 85 to 95% by weight, relative to the total weight of the cooling composition.

[0076] According to one embodiment, the coolant contains 100% by weight of the base oil relative to the total weight of the coolant.

[0077] Such base oils may be selected from base oils conventionally used in the lubricating oil field, such as synthetic or natural mineral oils, animal oils or vegetable oils or mixtures thereof.

[0078] There may be mixtures of various base oils, for example mixtures of two, three or four base oils.

[0079] The base oil used in the coolant used according to the invention may more particularly be a mineral oil or a synthetic oil belonging to group IV defined according to the API classification (or equivalent according to the ATIEL classification) and shown in Table 1 hereinafter, or a mixture thereof.

[0080] [Table 1]

[0081]

[0082] Mineral base oils include any type of base oil obtained by atmospheric and vacuum distillation of crude oil followed by refining operations such as solvent extraction, deasphalting, solvent dewaxing, hydrotreating, hydrocracking, hydroisomerization and hydrofinishing.

[0083] Mixtures of synthetic and mineral oils may further be used, which may be of biological origin or recycled.

[0084] The base oil of the coolant according to the invention may further be chosen from synthetic oils, such as certain carboxylic acid esters and alcohol esters, polyalphaolefins (PAO) and polyalkylene antifreeze agents (PAG), obtained by polymerization or copolymerization of alkylene oxides containing 2 to 8 carbon atoms, in particular 2 to 4 carbon atoms.

[0085] The PAO used as a base oil is obtained, for example, from a monomer containing 4 to 32 carbon atoms, such as octene or decene. The weight average molecular weight of the PAO can vary greatly. Preferably, the weight average molecular weight of the PAO is less than 600 Da. The weight average molecular weight of the PAO can further be in the range of from 100 to 600 Da, 150 to 600 Da, or further 200 to 600 Da.

[0086] Additional additives may be used in the coolant used in the present invention. Additives include antioxidants, anti-corrosion additives, anti-foaming additives and pour point depressants.

[0087] According to a particularly preferred embodiment, the cooling composition used according to the invention comprises at least one antioxidant additive. Antioxidant additives are generally able to retard the degradation of the composition during use. This degradation is most often manifested in the formation of deposits in the form of sludge or an increase in viscosity in the composition.

[0088] Antioxidant additives act in particular as free radical inhibitors or destroyers of hydroperoxides. Commonly used antioxidant additives include phenolic antioxidants, amine antioxidant additives, and phosphorus-sulfur antioxidant additives.

[0089] The coolant used according to the invention may contain 0.1 to 2% by weight of at least one antioxidant additive, relative to the total weight of the coolant.

[0090] The coolant used according to the invention may contain at least one anti-corrosion additive. Anti-corrosion additives advantageously slow down or prevent corrosion of metal parts of the battery.

[0091] The coolant used according to the invention may contain 0.01 to 5% by weight, preferably 0.1 to 2% by weight, of an anticorrosion agent, relative to the total weight of the coolant.

[0092] The coolant according to the invention may further comprise at least one defoaming agent. The defoaming agent may be selected from polyacrylate silicones, fluorinated compounds or waxes.

[0093] The coolant used according to the invention may contain 0.001 to 5% by weight, preferably 0.1 to 2% by weight, of a defoaming agent, relative to the total weight of the coolant.

[0094] The coolant used according to the present invention may further include at least one pour point depressant (PPD) additive. By slowing down the formation of paraffin crystals, pour point depressant additives generally improve the performance of the composition under cold conditions. Examples of pour point depressant additives include alkyl polymethacrylates, polyacrylates, polyaromatic amides, polyalkylphenols, polyalkylnaphthalenes, alkyl polystyrenes.

[0095] The coolant used according to the present invention may also be one or more fluorocarbons. Fluorocarbons include perfluorooctyl bromide.

[0096] The coolant used according to the invention may contain fluorocarbons in an amount ranging from 0.01 to 10% by weight, preferably from 0.1 to 5% by weight, advantageously from 0.5 to 2% by weight, relative to the total weight of the coolant.

[0097] The coolant according to the present invention may further comprise at least one antiwear agent. According to one embodiment, the antiwear agent is selected from phosphorus-containing antiwear agents, phosphorus-sulfur antiwear agents, phosphorus-amine antiwear agents and mixtures thereof, preferably selected from phosphorus-containing antiwear agents.

[0098] According to one embodiment, the antiwear agent is a phosphite polymer, preferably corresponding to formula (I);

[0099] [Chemical formula 1]

[0100]

[0101] in

[0102] - Each of R1, R2, R3 and R4 can be independently selected from C1-C20 alkyl,

[0103] C3-C22 alkenyl, C6-C40 cycloalkyl, C7-C40 cycloalkenyl, C1-20 methoxyalkyl glycol ether, and Y-OH;

[0104] --Y is selected from C2-C40 alkylene, C2-C40 alkyl lactone, -R7-N(R8)-R9-, wherein R7,

[0105] R8 and R9 are independently selected from hydrogen, C1-C20 alkyl, C3-C22 alkenyl, C6-C40 cycloalkyl, C7-C40 cycloalkenyl, C1-20 methoxyalkyl glycol ether,

[0106] --m is an integer from 2 to 100,

[0107] -n is an integer from 1 to 1000.

[0108] According to one embodiment, the weight average molecular weight of the phosphite polymer corresponding to formula (I) is preferably less than 30000 g / mol, preferably 3000-20000 g / mol. The weight average molecular weight can be measured by size exclusion chromatography.

[0109] According to one embodiment, the number average molecular weight of the phosphite polymer corresponding to formula (I) is preferably less than 10000 g / mol, preferably in the range of 1000 to 5000 g / mol. The number average molecular weight can be measured by size exclusion chromatography.

[0110] According to one embodiment, the polydispersity index of the phosphite polymer corresponding to formula (I) is preferably in the range of from 1 to 5, preferably 2 to 4.

[0111] The phosphite polymer that can be used in the present invention can be obtained according to the method described in document WO2011102861. More specifically, the polymer can be obtained according to the method described in paragraphs 27-32 of the document.

[0112] According to one embodiment, the antiwear additive is selected from phosphorus-sulfur additives, such as metal alkylthiophosphates, more particularly zinc alkylthiophosphates, more particularly zinc dialkyldithiophosphates or ZnDTP. Preferred compounds have the formula Zn((SP(S)(OQ 2 )(OQ 3 ))2, where QR 2 and Q 3 (same or different) independently represent an alkyl moiety, preferably an alkyl moiety containing 1 to 18 carbon atoms.

[0113] As examples, mention may be made of phosphorus-sulfur antiwear additives, monobutylthiophosphate, monooctylthiophosphate, monolaurylthiophosphate, dibutylthiophosphate, dilaurylthiophosphate, tributylthiophosphate, trioctylthiophosphate, triphenylthiophosphate, monooctylthiophosphite, ), trilaurylthiophosphate, monolaurylthiophosphite, monobutylthiophosphite, dibutylthiophosphite, dilaurylthiophosphite, tributylthiophosphite, trioctylthiophosphite, triphenylthiophosphite, trilaurylthiophosphite and salts thereof.

[0114] Phosphate amines are also anti-wear additives that can be used in the coolants of the present invention. However, the phosphorus provided by these additives can act as a poison in catalytic systems because they produce ash. This effect can be minimized by partially replacing the phosphate amines with additives that do not provide phosphorus, such as polysulfides, especially sulfur-containing olefins.

[0115] The coolant used according to the invention may contain an antiwear agent in an amount ranging from 0.01 to 15% by weight, preferably from 0.1 to 10% by weight, preferably from 1 to 5% by weight, relative to the total weight of the composition.

[0116] The additives can be introduced individually and / or in the form of additive mixtures according to methods well known to those skilled in the art.

[0117] Advantageously, the coolant used according to the invention has a relative humidity of from 1.5 to 35 mm, measured at 40° C. according to standard ASTM D445. 2 / s range, more particularly from 2 to 25 mm 2 / s, even from 2.5 to 10mm 2 The kinematic viscosity is in the range of / s.

[0118] Advantageously, the coolant used according to the invention has a thickness of from 0.5 to 7 mm, measured at 100° C. according to standard ASTM D445. 2 / s range, more particularly from 1 to 4 mm 2 / s, even from 1.1 to 2.5 mm 2 The kinematic viscosity is in the range of / s.

[0119] Alternatively, the coolant used according to the invention may consist exclusively of at least one mineral or synthetic base oil, which may be of biological origin or recycled.

[0120] The thermal and safety management method according to the present invention comprises the following consecutive steps:

[0121] a) a step of detecting a fault in at least one electrochemical cell of at least one module of the battery,

[0122] b) When a fault is detected, the step of increasing the flow of coolant through the module(s) containing at least one faulty battery cell.

[0123] According to one embodiment, if at least one parameter selected from temperature and current is above or below a given threshold, the battery cell will be considered to be faulty.

[0124] In the framework of the present invention, a module is considered to be faulty if it comprises at least one faulty battery cell.

[0125] Therefore, typically, if no fault is detected, the flow of coolant through the battery module is unchanged.

[0126] According to one embodiment, step a) comprises the following steps:

[0127] a1) setting a threshold value of at least one parameter selected from temperature, voltage and current,

[0128] a2) measuring said at least one parameter selected from temperature, voltage and current during operation of the battery, wherein said measurements can be performed continuously or sequentially,

[0129] a3) comparing said at least one measured parameter with said threshold value,

[0130] a4) When the measured parameter is above or below the threshold value set during step a1, a fault is detected. According to one embodiment, the parameter is the temperature of each module, then step a) of the method according to the invention preferably comprises the following steps:

[0131] a1) Setting a temperature threshold T1 that should not be exceeded,

[0132] a2) Measure the temperature T2 of each module,

[0133] a3) performing a comparison between the measured temperature and a temperature threshold,

[0134] a4) When the measured temperature of a given module exceeds the threshold temperature value determined during step a1 (when T2>T1), a fault in said module is detected.

[0135] According to one embodiment, the parameter is the temperature of each battery cell, and step a) of the method according to the present invention preferably comprises the following steps:

[0136] a1) Setting a temperature threshold T1 that should not be exceeded,

[0137] a2) measuring the temperature T2 of each battery cell,

[0138] a3) performing a comparison between the measured temperature and a temperature threshold,

[0139] a4) When the measured temperature of a given battery cell exceeds the threshold temperature value determined during step a1 (when T2 > T1 ), a fault in said battery cell is detected.

[0140] According to one embodiment, the parameter is the coolant temperature at the outlet of each module, and step a) of the method according to the invention preferably comprises the following steps:

[0141] a1) Setting a temperature threshold T1 that should not be exceeded,

[0142] a2) measuring the coolant temperature T2 at the outlet of each module,

[0143] a3) performing a comparison between the measured temperature and a temperature threshold,

[0144] a4) When the temperature measured at the outlet of a given module exceeds the temperature threshold determined during step a1 (when T2>T1), a fault in said module is detected.

[0145] According to one embodiment, the parameter is the coolant temperature at the outlet of each battery cell, then step a) of the method according to the present invention preferably comprises the following steps:

[0146] a1) Setting a temperature threshold T1 that should not be exceeded,

[0147] a2) measuring the temperature T2 of the coolant at the outlet of each battery cell,

[0148] a3) performing a comparison between the measured temperature and a temperature threshold,

[0149] a4) When the temperature measured at the outlet of a given battery cell exceeds the threshold temperature value determined during step a1 (when T2>T1), a fault in said battery cell is detected.

[0150] According to one embodiment, step a) comprises the following steps:

[0151] a1) setting a threshold value of a change in at least one parameter within a predetermined time, wherein the at least one parameter is selected from temperature, voltage and current,

[0152] a2) measuring the at least one parameter selected from the group consisting of temperature, voltage and current during operation of the battery, wherein the measurements can be performed continuously or sequentially,

[0153] a3) When the threshold set during step a1 is reached, a fault is detected.

[0154] According to such an embodiment, a fault is detected when a parameter changes too quickly.Thus, a threshold value for said parameter may be set such that if the parameter changes too quickly within a given predetermined time, this value is deemed to have been reached.

[0155] If the parameter is temperature, the threshold may be the change in said temperature over a predetermined period of time. Thus, if the temperature changes very quickly (ie, by a certain magnitude within a given time), it may be considered a sign that the battery cell is faulty.

[0156] As a non-limiting example, if the coolant temperature at the outlet of a module or battery cell changes by at least 20°C, or even at least 10°C, or even at least 5°C within a given time, e.g. 10 seconds, then the battery cell may be considered to be faulty or the module may be considered to be faulty (or include at least one faulty battery cell).

[0157] As a non-limiting example, if the temperature of a module or battery cell changes by at least 20°C, or even at least 10°C, or even at least 5°C within a given time (e.g. 10 seconds), the module may be considered to be faulty (or include at least one faulty battery cell).

[0158] According to one embodiment, the parameter is a voltage and a fault in a battery cell is detected when the voltage of the battery cell reaches 0 V. According to such an embodiment, the threshold value of the parameter is 0V.

[0159] According to one embodiment, a fault is detected when the voltage drops too quickly.

[0160] As a non-limiting example, if the voltage of at least one battery cell varies by at least 3V, or even at least 2V, or even at least 1V within a predetermined time, such as 10 seconds, the battery cell may be considered faulty.

[0161] Voltage is a clear, easily determined indicator of battery, cell or module failure / malfunction.

[0162] Typically, each module comprises an inlet for adding coolant to the module and an outlet for extracting coolant from the module.

[0163] According to one embodiment, each module includes conduits, referred to as coolant conduits, that allow coolant to circulate in the module over all or part of the length of each battery cell within the module.

[0164] The measurements of a given parameter may be taken continuously or sequentially at regular time intervals.

[0165] According to one embodiment, step b) of regulating at least part of the flow comprises increasing the flow of the coolant in one or more modules having at least one faulty battery cell and decreasing the flow of the coolant in one or more modules having no faulty battery cells.

[0166] The traffic conditioning step b) may also be referred to as a traffic redirection step.

[0167] Therefore, according to the invention, the regulation step b) is a traffic redirection step.

[0168] According to the invention, redirection of flow means that at least part of the coolant circulating in one or more modules at a given flow during nominal operation is redirected from one or more modules not having any faulty battery cell to one or more modules having at least one faulty battery cell.

[0169] According to one embodiment, a variable opening valve may be used to allow the flow rate to be adjusted during step b), whereby said valve is preferably located upstream of each module on the cooling circuit.

[0170] According to one embodiment, the valve is a solenoid valve.

[0171] According to one embodiment of the thermal and safety management method of the present invention, the flow regulation step b) includes the step of closing at least one valve upstream of at least one module without any faulty battery cell, preferably the step of closing each valve upstream of each module without any faulty battery cell.

[0172] According to one embodiment, the valve is a shut-off valve for stopping the circulation of coolant in each module without any faulty battery cell.

[0173] Thus, generally within the framework of the present invention, for a battery having X modules (in a fluidic sense, the modules are connected in parallel) and operating with a total flow rate D of coolant;

[0174] - in nominal operation, each module m receives D / X% of the total flow D, i.e. the flow of coolant is evenly distributed in each module of the battery,

[0175] -When a fault is detected in at least one battery cell of one of the modules, the module having at least one faulty battery cell receives a flow rate that will be greater than D / X%. In other words, the flow rate is no longer evenly distributed, but the flow rate is adjusted so that the total flow rate received by the faulty module is greater than the total flow rate received by each of the other modules without faults.

[0176] According to one embodiment of the management method of the present invention, the battery includes at least 3 modules connected in parallel, and at least 50% of the coolant flow is redirected to one or more modules including at least one faulty battery cell, preferably at least 70% of the flow, more preferably at least 90% of the flow, or even 100% of the coolant flow is directed to one or more modules including at least one faulty battery cell.

[0177] According to one embodiment, from 50% to 90% of the coolant flow is redirected to one or more modules having at least one failed battery cell, such that one or more modules not having any failed battery cells continue to be in contact with the coolant.

[0178] According to one embodiment of the management method of the invention, the regulating step b) is performed until one or more failed battery cells return to nominal operation.

[0179] As defined in the present invention, a battery cell having nominal operation thereafter is not considered to be faulty.

[0180] Preferably, the faulty cell is considered to have nominal operation when its temperature is below 100° C., preferably 50° C. Therefore, according to one embodiment of the management method of the present invention, step b) of regulating the flow is performed until the faulty cell regains a temperature below 100° C., preferably 50° C.

[0181] According to one embodiment, the thermal and safety management method is implemented by a device.

[0182] According to one embodiment, a device for implementing a thermal and safety management method comprises a temperature sensor for a coolant at an inlet of a battery and a temperature sensor for a coolant at an outlet of the battery.

[0183] According to one embodiment, the device for implementing the thermal and safety management method comprises a temperature sensor for the coolant, making it possible to determine the coolant temperature at the outlet of each module and / or each battery cell. Such an embodiment is particularly relevant when the determined parameter is the coolant temperature at the outlet of each module and / or each battery cell.

[0184] According to one embodiment, the device for implementing the thermal and safety management method comprises a temperature sensor for determining the temperature of each module and / or each battery cell. Such an embodiment is particularly relevant when the determined parameter is the temperature of each module and / or each battery cell.

[0185] Thus, according to a particularly advantageous embodiment, the device comprises a battery comprising a plurality of modules, each module comprising a plurality of battery cells, and a cooling circuit comprising a circulation loop for a coolant and a control valve for regulating the flow of said coolant upstream of each module, the coolant circulating at a given flow rate in nominal operation and in direct contact with the battery cells, and the thermal and safety management method of the invention advantageously comprises the following steps:

[0186] a1) setting a threshold value of at least one parameter selected from temperature, voltage and current,

[0187] a2) measuring at least one parameter selected from temperature, voltage and current during operation of the battery,

[0188] a3) When the measured parameter is above or below the threshold value set during step a1, a fault is detected,

[0189] b) When a fault is detected, the flow redirection step includes (i) increasing the coolant flow through the module(s) having at least one faulty battery cell, and (ii-1) reducing the coolant flow through the module(s) not having at least one faulty battery cell, or (ii-2) stopping the coolant flow through the module(s) not having at least one faulty battery cell.

[0190] Thus, according to a particularly advantageous embodiment, the device comprises a battery and a cooling circuit, the battery comprising a plurality of modules, each module comprising a plurality of battery cells, and the cooling circuit comprising a circulation loop for a coolant and a control valve for regulating the flow of said coolant upstream of each module, the coolant circulates at a given flow rate in nominal operation and in direct contact with the battery cells, and the thermal and safety management method of the invention advantageously comprises the following steps:

[0191] a1) Setting a temperature threshold for each module or each battery cell that should not be exceeded,

[0192] a2) measuring the temperature of each module of each battery cell,

[0193] a3) when the measured temperature of at least one given module or at least one given battery cell exceeds a temperature threshold, a fault in said module or said battery cell is detected,

[0194] b) When a fault is detected, the flow redirection step includes (i) increasing the coolant flow through the module(s) having at least one faulty battery cell, and (ii-1) reducing the coolant flow through the module(s) not having at least one faulty battery cell, or (ii-2) stopping the coolant flow through the module(s) not having at least one faulty battery cell.

[0195] Another subject of the invention is a device comprising:

[0196] - a battery comprising a plurality of modules, each module comprising a plurality of electrochemical cells,

[0197] -Cooling system, including:

[0198] oCirculation loop for coolant,

[0199] oAt least one valve upstream of each module to control the flow of coolant.

[0200] According to one embodiment, the device further comprises a control unit for detecting at least one faulty battery cell.

[0201] According to one embodiment, the device further comprises at least one sensor at the outlet of each module or for measuring at least one parameter chosen among temperature, voltage and current.

[0202] According to one embodiment, the device also comprises at least one heat exchanger intended to be connected to an air-conditioning circuit in which a refrigerant fluid flows.

[0203] Therefore, according to a particular embodiment of the invention, the device comprises:

[0204] - a battery comprising a plurality of modules, each module comprising a plurality of electrochemical cells,

[0205] -An exchanger also called a radiator, which is used to reject part of the heat stored in the coolant to the outside air,

[0206] - a cooler (for example a plate heat exchanger) which allows heat exchange with the air or with another coolant circuit reserved for the vehicle air conditioning (the so-called "refrigerant" fluid),

[0207] - a heating system, where appropriate, for increasing the temperature of the coolant in order to heat the battery during a cold start or when the vehicle is operated in a cold atmosphere,

[0208] - at least one pump,

[0209] - a circulation loop for the coolant, and

[0210] - Valves, used to initiate and control flow throughout the circuit.

[0211] The features and advantages defined for the management method according to the invention also apply to the device according to the invention.

[0212] According to one embodiment, the device according to the invention further comprises a temperature sensor for the coolant at the inlet of the battery and a temperature sensor for the coolant at the outlet of the battery.

[0213] According to one embodiment, the device according to the invention further comprises a temperature sensor for the coolant to determine the coolant temperature at the outlet of each module and / or each battery cell. Such an embodiment is particularly relevant when the determined parameter is the coolant temperature at the outlet of each module and / or each battery cell.

[0214] According to one embodiment, the device according to the invention further comprises a temperature sensor for determining the temperature of each module and / or each battery cell. Such an embodiment is particularly relevant when the determined parameter is the temperature of each module and / or each battery cell.

[0215] According to one embodiment, in addition to the cooling circuit, the device also includes an air conditioning circuit. Such an air conditioning circuit can exchange heat through a cooler of the cooling circuit and can also include a compressor, an expansion valve and a condenser. The air conditioning circuit can circulate a refrigerant fluid, such as a hydrofluoroolefin, such as HFO-1234yf.

[0216] According to such an embodiment, heat exchange may be performed between the coolant and the refrigeration fluid via the chiller.

[0217] The air conditioning system may contain a compressor. The function of the compressor is to increase the pressure level of the gaseous refrigerant fluid at the outlet of the heat exchanger before the refrigerant fluid passes through the condenser and liquefies in the condenser.

[0218] An expansion valve, such as an electronic expansion valve, may be present in the air conditioning system. This valve reduces the pressure and controls the flow of the refrigerant fluid coming from the condenser at its outlet in order to maximize the efficiency of the plate heat exchanger. In practice, the valve allows the pressure of the coolant to be reduced, so that it is at a temperature and pressure condition very close to its liquid-gas equilibrium, and allows the optimal amount of coolant to pass, thus completing the phase change (made possible by increasing the heat provided by the coolant).

[0219] A condenser may be present in an air conditioning system. This condenser is used to convert the pressurized gas at the outlet of the compressor into a pressurized liquid.

[0220] The invention can be used in electric vehicles to avoid thermal runaway of the battery.Thus, the device according to the invention can be used in electric and hybrid vehicles, in particular rechargeable hybrid vehicles.

[0221] An "electric vehicle" as defined in the present invention refers to a vehicle including an electric motor as the sole propulsion means, while a hybrid vehicle includes an internal combustion engine and an electric motor as a combined propulsion means.

[0222] The "propulsion device" defined in the present invention refers to a system including the mechanical components required for the propulsion of an electric vehicle. Therefore, the propulsion system more specifically includes an electric motor including a rotor-stator assembly of a power electronics system (dedicated to speed regulation), a transmission and a battery.

[0223] The device according to the invention can also be used in energy storage assemblies or aircraft.

[0224] The invention will now be described by the following examples which are of course given as illustration of the invention but not limiting thereof.

[0225] Example

[0226] In order to demonstrate the advantages of the management method of the present invention, a model was implemented using the software Simulation X.

[0227] The model consists of a battery pack consisting of 16 6-cell modules in an 8p2s configuration (2 rows of 8 parallel modules). The battery cells in the model are "pouch" type cells, 276mm high, 176mm long, 8mm thick, and have a capacity of 40Ah using NMC technology.

[0228] From a fluid dynamics point of view, the heat transfer fluid (coolant) thus circulates in fluid ducts of rectangular cross-section (276 mm high and 2 mm wide) over the entire length of the battery cell (176 mm). Two buffers at the inlet and outlet of the module provide a uniform flow distribution between each fluid duct. Its thickness is 5 mm, its height is 276 mm, and its width corresponds to 6 battery cells and 6 fluid ducts, i.e. 60 mm.

[0229] From a system modeling perspective, the 3D configuration was approximated using fluid volumes (2 volumes corresponding to the buffers and 6 volumes corresponding to the fluid conduits) and ducts with rectangular cross-sections to calculate the pressure drop resulting from the coolant circulation.

[0230] The battery cell is represented by a solid heat capacity which is determined by its size (as described above), density (2700 kg.m -3 ) and specific heat capacity (900 J.kg -1 .K -1 ) to parameterize.

[0231] In addition, from Figure 4 As can be seen in Figure 1, each battery cell is connected to a controllable heat source, allowing nominal operation or thermal runaway configurations to be studied as required.

[0232] To complete the system model of the module, the thermofluid coupling, i.e. the heat transfer between the battery cells (solid heat capacity) and the coolant (fluid volume), is implemented using a function that expresses the heat transfer coefficient as a function of the average velocity of the flow in the fluid pipe, which is calculated from the 3D simulation (see Figure 5 ).

[0233] In the selected configuration (8p2s), a runaway is selected to occur in one of the battery cells of one of the modules in the first row. This configuration has a higher criticality because the coolant leaving the runaway module must pass through the modules in the second row.

[0234] Assuming that the coolant supply to all modules is uniform upstream and downstream of the modules (eg, via a manifold), the configuration can be simplified numerically by considering that all modules of the same row that are not directly experiencing a runaway will behave exactly the same.

[0235] The pump chosen for this study is a positive displacement pump, which has the advantage of high operating efficiency. The pump is speed-controlled and provides a variable flow rate depending on the pressure level (and the resulting head loss) present in the fluid circuit. The advantage of constant speed controlled operation is that it is possible to quantify the efficiency of the regulation of the flow profile by taking into account the possible increase in head loss.

[0236] Valves are elements used to regulate flow between different modules, especially between the module experiencing loss of control and other modules. In this model, variable opening valves are used to accurately control flow distribution.

[0237] For the module connected in parallel with the module experiencing runaway, different opening degrees were tested;

[0238] - 100% corresponds to the situation where each module receives an “equal” portion of the flow (in reality, the increase in flow in the uncontrolled module is very small due to the reduction in head losses caused by coolant heating);

[0239] -30% corresponds to a situation where slightly more than half of the coolant (57.3%) enters the module that is experiencing runaway;

[0240] -10%, corresponds to the situation where most of the coolant (93.3%) passes through the module that is experiencing runaway, and only a small amount of circulation is maintained among the parallel modules.

[0241] -0%, corresponds to the situation where all flow delivered by the pump is redirected to the override module.

[0242] It should be noted that in all cases, the flow was adjusted to favor the module experiencing runaway, and this adjustment was synchronized in time with the outbreak of runaway.

[0243] The developed model contains three temperature probes and one pressure probe. The temperature sensors are used to measure the coolant temperature upstream of the battery pack, at the outlet of the lost module, and at the outlet of the battery pack. The pressure sensor is placed upstream of the pump in order to calculate the precise head loss of the system and adjust the pump flow rate.

[0244] The coolant used in the study was an oil with the following properties;

[0245] Density at -25℃ is 0.7740g / cm3

[0246] Density at -50°C is 0.7650g / cm3

[0247] Density at -100°C is 0.7225 g / cm3

[0248] --The kinematic viscosity at 25℃ is 27mm 2 / s

[0249] The kinematic viscosity at -0°C is 9 mm 2 / s level

[0250] The kinematic viscosity at -40°C is 3 mm 2 / s level

[0251] The kinematic viscosity at -100°C is 1 mm 2 / s level

[0252] The thermal conductivity at -40°C is on the order of 0.1275W / (mK)

[0253] The thermal conductivity at -80℃ is on the order of 0.1175W / (mK)

[0254] -Heat capacity is 2100 J.kg -1 .K -1 .

[0255] The model also includes an air conditioning system consisting of a plate heat exchanger (chiller), a compressor, an electronic expansion valve and a condenser.

[0256] The plate heat exchanger allows cooling of the battery circuit coolant. The heat exchange is produced by the phase change (liquid-vapor) of the refrigerant fluid (R1234yf). The height of the exchanger is 170 mm, the width is 80 mm and the thickness is 68 mm. The thickness of each plate is 0.35 mm and the exchanger has 0.78 plates per mm.

[0257] The function of the compressor is to increase the pressure level of the gaseous refrigerant fluid at the outlet of the heat exchanger before it passes through the condenser and is liquefied in the condenser.

[0258] For a given compressor geometry, the pressurization level can be directly controlled by adjusting the consumed power or the speed. In this model, it is the second parameter that is adjusted by the control strategy in order to meet the temperature set point of the coolant at the inlet of the battery pack.

[0259] The set temperature during the stable operation phase was 25 °C, while the set temperature from the onset of thermal runaway until the end of the simulation was 20 °C.

[0260] It should be noted that in order to maintain consistency in the response dynamics of the compressor, and more specifically to prevent excessive increases in speed with increases in coolant temperature during thermal runaway, reaction time and speed thresholds have been imposed on the regulation.

[0261] The influence of the maximum allowed rotational speed on the performance and flow regulation value of the exchanger was studied in simulations using two values: 1250 rpm and 5000 rpm.

[0262] To maximize the efficiency of the plate heat exchanger, the electronic expansion valve reduces the pressure and controls the flow of the refrigerant fluid at the outlet of the condenser. In fact, the valve must reduce the pressure of the coolant to bring it to a temperature and pressure condition very close to its liquid-gas equilibrium and let through the optimal amount of coolant to complete the phase change (made possible by the increase in the heat provided by the coolant).

[0263] In the model, as in reality, the intensity of the depressurization is controlled by a control strategy that varies the degree of opening of the valves in order to meet a set point of 5 ° C when the refrigeration fluid runs away at the outlet of the exchanger. This set point ensures that when the set point is reached, the entire refrigeration fluid has changed state. As for the compressor, a threshold has been imposed on the regulation of the valve opening level, in particular to prevent the valve from closing completely, which in turn would cause problems with the convergence of the model.

[0264] As the name implies, the function of the condenser is to convert the pressurized gas at the compressor outlet into a pressurized liquid. In order to limit the number of variables in the model, all parameters controlling the operation of the condenser are frozen. The outside air temperature is set to 20°C and the pump flow rate is set to 100l / s. The height of the condenser is 590mm, the width is 326mm, and the thickness is 29mm. The inner diameter of the tube is 10mm and the tube wall thickness is 1mm. There are 48 tubes in each row.

[0265] Loss of control occurs:

[0266] Each calculation consists of a time simulation of the system running for one hour (3600 s) according to the following numerical protocol;

[0267] - At t=0s, a heat source of 20 W is applied to all cells of the battery pack to represent stable operating conditions.

[0268] - From t=0s to t=1500s, the control strategy implemented in the pilot air conditioning loop increases the speed of the compressor in order to increase the heat absorbed by the plate heat exchanger and meet the 25°C temperature requirement imposed on the coolant at the inlet of the battery pack.

[0269] - At t=1500s, when the system is fully stable (i.e., no evolution of the main variables solved in the two loops), a thermal runaway event is generated by applying a dissipated thermal power of 722.67kW to one of the battery elements of one module of the first row (cell 2) during 10s. Flow regulation is immediately activated (when flow regulation is also tested) and the temperature set point of the coolant entering the battery pack is reduced from 25°C to 20°C.

[0270] - From t=1510s to t=3600s, no heat source is applied to the battery and the control strategy is allowed to control the cooling of the fluid.

[0271] Example 1: Reference Case

[0272] For comparison with the method of the present invention, a reference configuration was simulated.

[0273] In the reference configuration, traffic is evenly distributed between each module with no redirection.

[0274] The oil pump runs at 3000rpm, while the compressor is limited to 5000rpm.

[0275] The results obtained from the reference case are as follows Figures 1 to 4 shown.

[0276] Figure 1 It is shown that the oil pump flow rate remains relatively stable (about 22 l / min) throughout the simulation. Some fluctuations can be seen at the point of out-of-control outbreak (t=1500 s). Without regulation, these changes are essentially caused by changes in heat losses associated with changes in the temperature of the coolant.

[0277] Figure 2 It is shown that the flow rate of the coolant in the package module increases slightly at the moment of thermal runaway outbreak.

[0278] Figure 3 It is shown that the coolant temperature at the outlet of the module containing the failed battery cell rises sharply, while the coolant temperature at the inlet and outlet of the battery remains relatively stable.

[0279] When one of the modules in the first row went into runaway, the coolant temperature in all other modules dropped slightly due to the removal of power to the cell (which was previously continuously dissipating 20W of heat). This resulted in a slight increase in head loss and a decrease in flow. The flow increased again temporarily as the fluid recovered the heat generated by the thermal runaway cell, and then decreased again as the fluid cooled.

[0280] Figure 4 It is shown that the temperature of the battery cell adjacent to the faulty battery cell (packaged battery cell) reaches 67° C. This temperature seems relatively low enough to prevent any risk of propagation, but it should be noted that the model does not take into account certain phenomena, such as the release of gas at very high temperatures and the narrowing of the coolant ducts caused by the expansion of the packaged battery cell, which have a negative impact on the described situation. Figure 4 The failed battery cell was shown to reach temperatures above 750°C.

[0281] Therefore, the presented model is a good model for evaluating the technical advantages of the present invention.

[0282] Example 2: Traffic redirection (conditioning)

[0283] In such an example, the results of 3 levels of regulation (or redirection) are compared to a reference configuration (Example 1).

[0284] Adjust the intensity Figure 5 It is represented as the flow distribution between the encapsulated modules and the parallel modules.

[0285] Therefore, four regulation configurations were tested, corresponding to the ratio of coolant flow in the module experiencing runaway relative to the total flow:

[0286] -12.5% ​​(reference case),

[0287] -57.3% (partially open or partially regulated),

[0288] -93.3% (minimum aperture or almost full adjustment) and

[0289] -100% (closed or fully adjusted).

[0290] For each tuning configuration, Figure 5 The flow in the module with the cell experiencing runaway is shown in the upper part of the graph, and the flow in parallel modules is shown in the lower part of the graph.

[0291] from Figure 6 As can be seen in Figure 1, the flow regulation results in a slight change in the pump flow rate. The latter decreases as the flow rate in the module that is experiencing runaway increases. This decrease is due to the increase in head loss in the system.

[0292] Figure 7 The temperature trend of the fluid at the inlet of the cell is shown for each of the 4 conditioning configurations.

[0293] Figure 8 The temperature trend of the fluid at the outlet of a module experiencing a runaway is shown for each of the 4 regulation configurations.

[0294] Fig. 9 The temperature trend of the fluid at the outlet of the cell is shown for each of the 4 conditioning configurations.

[0295] from Figures 5 to 9 As can be seen from the comparison of , the head loss is controlled to first order (non-linear dependence) by the increase in velocity in the module that is experiencing runaway.

[0296] The reduction in total flow in the circuit when regulation occurs is an important consequence, as it can be expected that this will also entail a deterioration in the thermal management of the battery during runaway. However, this is not the result observed at the battery temperature of the module that is experiencing runaway.

[0297] Fig.10 The temperature trends of the battery cells adjacent to the battery cell experiencing runaway are shown for each of the four regulation configurations.

[0298] Fig.11 The temperature trends of a battery cell experiencing runaway are shown for each of the four regulation configurations.

[0299] like Fig.10 and Fig.11 As shown in the curves in , the flow regulation significantly reduces the temperature of both the runaway cell and the adjacent cells. Specifically, the maximum temperature of the runaway cell and the adjacent cells changes accordingly, from 752°C and 68.3°C in the reference case to 489°C and 58.2°C when the overall flow of coolant is redirected to the runaway module.

[0300] Furthermore, by regulating the flow rate, the dynamics of cooling were significantly improved. In the two most favorable cases, where the coolant was essentially redirected to the lost module, the adjacent cells regained their pre-loss temperature in less than 103 seconds.

[0301] Without adjustment, the cooldown time is multiplied by a factor of 3.5 ( Fig.10 ).

[0302] Thus, the flow regulation in favor of the runaway module serves to significantly limit the temperature rise of the runaway cell and its neighboring cells, thereby reducing the risk of runaway propagation. This result is therefore a major advance in terms of safety.

[0303] Flow regulation will also have a positive impact on the life of cells not directly experiencing a runaway by reducing the thermal stress experienced (a combination of factors such as the maximum temperature reached, the duration of the runaway, and the uniformity of temperature within the cell).

Claims

1. A method for thermal and safety management of a battery in a device, the device comprising a battery and a cooling circuit, the battery comprising a plurality of modules, each module comprising a plurality of battery cells, and the cooling circuit comprising a circulation loop for a coolant and a regulating valve for regulating the flow of the coolant upstream of each module, the method comprising the following steps: a) a step of detecting a fault in at least one battery cell of the module, b) when a fault is detected, including a flow redirection step of increasing coolant flow through one or more modules containing at least one faulty battery cell.

2. The method according to claim 1, characterized in that At least 50% of the coolant flow is redirected to the one or more modules including at least one faulty battery cell, preferably at least 70% of the flow, more preferably at least 90% of the flow, or even 100% of the coolant flow is directed to the one or more modules including at least one faulty battery cell.

3. The method according to claim 1 or 2, characterized in that: Step a) comprises the following consecutive steps: a1) setting a threshold value of at least one parameter selected from temperature, voltage and current, a2) measuring at least one parameter selected from temperature, voltage and current during operation of the battery, a3) When the measured parameter is above or below said threshold value set during step a1 , a fault is detected.

4. The method according to claim 3, characterized in that The parameter is the temperature of the coolant, and the method comprises: a1) Set a temperature threshold that should not be exceeded, a2) measuring the coolant temperature at the outlet of each module or at the outlet of each battery cell, a3) detecting a fault in at least one given module or cell when the temperature measured at the outlet of said module or cell exceeds said temperature threshold, b) redirecting at least part of the flow of the coolant towards the faulty module or the faulty circuit Module of the pool unit.

5. The method according to claim 3, characterized in that: The parameter is the temperature of each module or each battery cell, and the method comprises: a1) Setting a temperature threshold for each module or each battery cell that should not be exceeded, a2) measuring the temperature of each module of each battery cell, a3) When the measured temperature of at least one given module or at least one given battery cell exceeds the temperature threshold, a fault in the module or battery cell is detected, b) redirecting at least part of the flow of the coolant towards the faulty module or the The module of the faulty battery cell is described.

6. The method according to claim 1 or 2, characterized in that: Step a) comprises the following consecutive steps: a1) setting a threshold for the change of at least one parameter during a given time, the at least one parameter being selected from the group consisting of temperature, voltage and current, a2) measuring said parameter during operation of the battery, a3) When said threshold value is exceeded, a fault in at least one given module or at least one given battery cell is detected.

7. The method according to any one of claims 1 to 6, characterized in that Step b) further comprises reducing the flow of the coolant in one or more modules having no faulty battery cells.

8. The method according to any one of claims 1 to 7, characterized in that The regulating step b) is performed until the one or more failed battery cells are restored to nominal operation.

9. A device for implementing the method according to any one of claims 1 to 8, the device comprising: - a battery comprising a plurality of modules, each module comprising a plurality of electrochemical cells, -Cooling system, including: For the circulation loop of the coolant, At least one valve upstream of each module is used to control the flow of the coolant.

10. The device according to claim 9, characterized in that The at least one valve is a shut-off valve for stopping flow circulation in a module that does not include any failed battery cells.

11. The device according to claim 9 or 10, further comprising a control unit for detecting at least one faulty battery cell.

12. The device according to any one of claims 9 to 11, further comprising at least one sensor at the outlet of each module or each battery cell making it possible to measure at least one parameter chosen from the coolant temperature and the current.

13. Apparatus according to any one of claims 9 to 12, further comprising an air conditioning circuit in which a refrigerant fluid flows.

14. The device according to claim 13, characterized in that The cooling circuit also comprises at least one heat exchanger intended for exchanging heat with the air or with the refrigerant fluid of the air conditioning circuit.

15. The device according to any one of claims 9 to 12, characterized in that The cooling circuit also comprises at least one heat exchanger intended for exchanging heat with air.

Images