Automotive Battery Module

Abstract

The present invention relates to a battery (3) module (7) including a case (8) for housing a power storage cell (9) and a monitoring device (19) for diagnosing degradation of at least one of the power storage cells (9) housed in the case (8) of the module (7), the monitoring device (19) monitoring characteristics other than the temperature of a fluid housed in the case (8) of the module (7).

Description

[Technical Field]

[0001] The present invention relates to the field of batteries, more precisely to automotive battery modules. [Background technology]

[0002] The energy storage capacity of vehicles is being called for to be further improved, especially as countries impose pollution control standards through legislation. While it is true that the use of batteries can avoid the pollution caused by combustion of heat engines by replacing all or part of them with electric motors, this does not necessarily mean that they can be substituted under the same conditions of use.

[0003] The main disadvantage is the risk of thermal runaway in the storage cells, especially in lithium-ion batteries. Specifically, if the temperature rises too high, a chain reaction inside the storage cells can cause the electrolyte to evaporate, which can lead to overpressure inside the storage cells. In the worst case scenario, some or even all of the storage cells can go into thermal runaway, which can lead to a fire in the battery and, concomitantly, in the components surrounding the battery, i.e., in whole or in part, in the vehicle in which the battery is installed.

[0004] These disadvantages have already been addressed in WO 2021 / 001108, EP 3910349, DE 102020109269, FR 3112028, US 2012 / 003515, EP 3166175 and in the article "A survey of methods for monitoring and detecting thermal runaway of lithium-ion batteries", Journal of Power Sources, Elsevier, Issue 436, 20 July 2019, ISSN: 0378-7753.

[0005] Even more seriously, as the battery's current draw increases, the battery's discharge power increases (the Joule effect increases with the square of the discharge current), and users use fast charging stations more frequently (the Joule effect increases with the square of the charging current), further increasing the risk of thermal runaway.

[0006] Thus, battery temperature regulation has become a major challenge for automobiles that are required to comply with ever-stricter pollution control standards. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2021 / 001108 [Patent Document 2] European Patent Application Publication No. 3910349 [Patent Document 3] German Patent Application Publication No. 102020109269 [Patent Document 4] French Patent Application Publication No. 3112028 [Patent Document 5] US Patent Application Publication No. 2012 / 003515 [Patent Document 6] European Patent Application Publication No. 3166175 [Non-patent literature]

[0008] [Non-Patent Document 1] "A survey of methods for monitoring and detecting thermal runaway of lithium-ion batteries," Journal of Power Sources, Elsevier, Issue 436, July 20, 2019, ISSN: 0378-7753 Summary of the Invention [Problem to be solved by the invention]

[0009] In particular, an object of the present invention is to provide a battery module that can quickly detect the risk of thermal runaway in the power storage cells housed in the battery module. [Means for solving the problem]

[0010] To this end, the present invention is directed to a battery module for an automobile including a case for housing storage cells, characterized in that the battery module includes a monitoring device for monitoring the characteristics of a fluid contained in the module case for diagnosing deterioration of at least one of the storage cells housed in the module case, the monitoring device includes at least one sensing element mounted on the module case for identifying the presence of a contaminated fluid leaking from at least one of the storage cells that is different from the fluid contained in the module case, and the sensing element includes a conductivity sensor for measuring a change in conductivity in the fluid contained in the module case caused by the contaminated fluid leaking from at least one of the storage cells.

[0011] According to the present invention, it is assumed that a battery is formed from a plurality of modules electrically connected in parallel or series, which has several advantages. First, it is easier to regulate the temperature of a plurality of battery modules than an integrated unit containing the same number of storage cells. Second, it is easier to install a plurality of battery modules in a vehicle than an integrated unit containing the same number of storage cells. Furthermore, if only some of the storage cells are defective, it is easier to replace the module containing the defective storage cells than to replace the entire battery. In this way, it is understood that the defective storage cells can be quickly identified because the battery module to be checked is already known through the diagnosis of the monitoring device.

[0012] Furthermore, each module is advantageously able, according to the invention, to detect the deterioration of at least one of its storage cells in order to stop thermal runaway of the battery as soon as possible. An obvious solution to solve the problem of thermal runaway would be to monitor the temperature of the storage cells, but this is not the solution pursued by the invention, since in practice the temperature rise occurs just before the ignition.

[0013] For example, it has been found that in order to avoid deformation of each storage cell, i.e., deterioration of the components surrounding the storage cell, an exhaust valve, often formed by a frangible part that breaks when a predetermined internal pressure is exceeded, is usually provided to release the excessive pressure outside the storage cell. If the exhaust valve opens in this way, the storage cell will no longer function.

[0014] Based on this recognition, the present invention does not track the temperature of each storage cell, but rather monitors at least one characteristic other than temperature, such as the conductivity of the fluid within the battery module, and possibly also its composition, pressure or clarity, to identify whether a contaminating fluid, such as gas, is leaking from at least one of the storage cells of the module and quickly diagnose the possibility of thermal runaway.

[0015] In fact, installing a temperature sensor in each storage cell is costly and complicated, and measuring a single temperature inside the case does not reliably and early enough detect thermal runaway in any one storage cell. According to the present invention, an alternative method is used to detect an abnormality after destruction of at least one of the storage cells. In this way, the location of a thermal runaway event in a battery module is immediately identified (especially earlier than with temperature monitoring) at a stage sufficient to prevent the thermal runaway from spreading to other storage cells and / or other battery modules in the battery module. Furthermore, according to the present invention, the monitoring device is advantageously compatible with various types of temperature regulation systems.

[0016] According to the present invention, the sensing elements can advantageously be mounted either inside or outside the case of each module depending on the mounting arrangement or type of battery. Of course, for improved diagnostic capabilities, there may be multiple identical sensing elements (sensing the same characteristic of the fluid in the battery module) and / or different sensing elements (sensing multiple different characteristics of the fluid in the battery module) on the same module.

[0017] Conductivity sensors are preferred because they are more reliable for detecting characteristics in fluids than other characteristics. For example, conductivity sensors are less affected by other characteristics of the fluid (e.g., color, clarity, etc.) that may interfere with / alter the measurement of the characteristic. In other words, conductivity sensors produce fewer erroneous measurements than other types of sensors in the context of the present invention.

[0018] According to the present invention, advantageously, if the change in the conductivity (or conversely, resistivity) of the fluid in the module deviates from a predetermined threshold (such as the average conductivity of the other battery modules, a deviation from the normal conductivity at a specific temperature, or a deviation from a predetermined conductivity), the monitoring device can immediately diagnose a possible thermal runaway.

[0019] According to the present invention, advantageously in the special case where the fluid is air, the conductivity sensor can also detect an increase in humidity in the air, which usually leads to a short circuit (air dielectric breakdown) that occurs before thermal runaway. In other words, the conductivity sensor not only diagnoses thermal runaway, but also prevents it, which none of the other types of sensors, such as temperature or pressure sensors, can do.

[0020] The present invention may also include one or more of the following optional features, either alone or in combination.

[0021] The sensing element may further include a concentration sensor for measuring the concentration of a contaminating fluid that has leaked from at least one of the storage cells into the fluid contained in the module case, such that it is understood that the presence of even a small amount of contaminating fluid can immediately cause the monitoring device to diagnose a possible thermal runaway.

[0022] The sensing element may further comprise a pressure sensor for measuring a change in pressure in the fluid contained in the case of each module caused by a contaminated fluid leaking from at least one of the storage cells. Advantageously, according to the present invention, if the change in pressure of the fluid in the module exceeds a predetermined threshold (such as the average pressure of the other battery modules, a deviation from the normal pressure at a specific temperature, or a deviation from a predetermined pressure), the monitoring device can immediately diagnose a possible thermal runaway.

[0023] The detection element may further include an optical sensor for measuring changes in light transmission in the fluid contained in the case of each module, caused by contaminated fluid leaking from at least one of the storage cells. According to the present invention, advantageously, if the change in light intensity of the fluid in the module exceeds a predetermined threshold (e.g., deviation from the average light intensity of the other battery modules or from a predetermined light intensity), the monitoring device can immediately diagnose a possible thermal runaway. It is noted that this last type of sensor can also perform other additional detection functions. For example, immediately after a fire breaks out in a module, the monitoring device can detect smoke by a decrease in light intensity, or conversely, flames by an increase in light intensity. Furthermore, if the fluid in the module is liquid, the monitoring device can detect gas bubbles leaking from the storage cells by a change in light intensity.

[0024] The monitoring device may include at least one guide element attached to the case of the module for diverting contaminated fluid leaking from at least one of the storage cells toward the detection element, in order to improve detection reliability and limit the number of detection elements. It is understood that this guide element may form part of the top cover of the case of each module, in order to force the contaminated fluid to pass in front of each detection element. In this way, the guide element may form a collector that forces all contaminated fluid to pass in front of each detection element.

[0025] The fluid contained within the module case may be air in a gaseous phase or a dielectric heat transfer fluid in a liquid phase that regulates the temperature of at least a portion of the energy storage cells contained within the battery module.

[0026] The present invention also relates to a temperature regulation system for an automotive battery module as introduced above, characterized in that the temperature regulation system includes a control unit electrically connected to a monitoring device for a fluid contained in the case of the module for selectively controlling the function of the temperature regulation system in response to diagnosed deterioration of at least one of the storage cells contained in the case of the module.

[0027] The invention furthermore relates to a motor vehicle, characterized in that it includes a climate control system as introduced above.

[0028] Other characteristics and advantages of the invention will become apparent from the following description, given by way of non-limiting example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a schematic top view of an example of a vehicle equipped with a temperature regulation system for a battery module according to the present invention; [Figure 2] 1 is a schematic perspective view of an example of a battery module according to a first embodiment of the present invention. [Figure 3] FIG. 6 is a schematic cross-sectional view of an example of a battery module according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] In the following, directions are those of the respective drawings, and in particular the terms "up", "down", "left", "right", "upper", "lower", "forward" and "rearward" are generally understood relative to the directions shown in the respective drawings.

[0031] The present invention applies to all types of battery 3 temperature regulation systems 1, including in particular systems fitted to passenger car type vehicles 4, SUVs ("Sport Utility Vehicles"), two-wheelers (especially motorbikes), airplanes, and commercial vehicles selected from among light trucks, "heavy haulers" (i.e. subways, buses, over-the-road vehicles (trucks, tractors, trailers), off-road vehicles such as agricultural or earthmoving machinery) or other transport or material handling machines.

[0032] The motor vehicle 4 may be of the electric type, i.e. having at least one electric motor powered by at least one battery; of the hybrid type, i.e. having at least one internal combustion engine supplied with at least one fuel (gasoline, liquefied petroleum gas, diesel, natural gas for vehicles, biofuels such as ethanol derived primarily from plant materials, etc.) and assisted by at least one battery and / or at least one electric motor powered by the on-board electrical network of the motor vehicle 4; of the fuel cell type, i.e. having at least one battery and / or at least one electric motor powered by a fuel cell fueled by dihydrogen (for example supplied from a pressure tank) and dioxygen (for example supplied from the ambient air); or of the plug-in hybrid type, i.e. having at least one internal combustion engine supplied with at least one fuel (gasoline, liquefied petroleum gas, diesel, natural gas for vehicles, biofuels such as ethanol derived primarily from plant materials, etc.) and at least one electric motor powered by at least one rechargeable battery connected to the on-board electrical network of the motor vehicle 4 and / or to an electrical network external to the motor vehicle 4. Of course, the invention is not limited to the examples of the respective vehicles 4 described above, but can be applied to any type of vehicle 4 including at least one battery without departing from the framework of the invention.

[0033] "Temperature regulation system 1" refers to any type of system 1 capable of managing the flow, temperature and pressure of a heat transfer fluid surrounding some of the storage cells 9 of a battery 3, exchanging heat with all or part of the storage cells 9 (by immersion in a dielectric heat transfer fluid, by blowing air, by an air exchanger) in order to regulate the temperature of the storage cells, i.e., to typically heat and / or cool all or part of the storage cells 9 in at least one battery 3 module 7 in accordance with a predetermined control.

[0034] The term "heat transfer fluid" refers to a fluid in the temperature regulation system 1 that can exchange heat and / or cold by contact with at least some of the storage cells 9 of the battery 3. Typically, the heat transfer fluid fills at least a portion of the battery 3 module 7, allowing it to circulate around all or some of the storage cells 9.

[0035] The term "dielectric heat transfer fluid" refers to a fluid that remains in liquid form within the battery 3 module 7 of the temperature regulation system 1 for contact-based exchange of heat and / or cold with at least some of the storage cells 9 of the battery 3. Typically, the dielectric heat transfer fluid is single-phase, i.e., it does not change phase (remains liquid) within the temperature range during normal operation, e.g., between -40°C and 60°C. According to the present invention, the heat transfer fluid is dielectric and preferably has an electrical resistivity ρ of 1·10 at a temperature of 300 Kelvin (300K), in particular so as not to interfere with the electrical connection between the cells 9 within the same battery 3 module 7. 9 ohm-meter (1 GΩ m) or more, or conversely, conductivity σ of 1·10 at a temperature of 300 Kelvin (300 K). -9 siemens per metre (1nS m -1) indicates the following. This type of dielectric heat transfer fluid can be a fluid similar to those used in transformers, i.e. it is known per se and will not be further described here. By way of non-limiting example only, the dielectric heat transfer fluid can be, for example, a product of the Novec® 7500 type sold by the company 3M®, of the F18 or F20 type sold by the company Total®, or of the DF7 or DFK type sold by the company MiVolt®.

[0036] "Fluid characteristics" refers to the physicochemical characteristics of a fluid, not its mass or volume.

[0037] "Storage cell 9" refers to any type of electrochemical storage cell that can store and reversibly release electrical energy.

[0038] The term "battery 3 module 7" refers to a case 8 that groups together at least two of the storage cells 9 electrically connected in series or parallel. In the framework of the present invention, the circulation of a heat transfer fluid within at least one battery 3 module 7 is envisaged in order to regulate the temperature of at least some of the storage cells 9 housed within the battery 3 module 7.

[0039] "Battery 3" refers to an assembly of modules 7 electrically connected in series or parallel, and optionally, to an assembly of storage cells 9 contained within the modules 7.

[0040] "Powertrain 2" refers to the assembly including one (or more) engines that directly or indirectly drive the wheels of the motor vehicle 4, and the accessories for each engine, such as an alternator, cooling system, gearbox or lubrication system.

[0041] In the example shown in Figure 1, a climate control system 1 for a battery 3 is mounted in a motor vehicle 4. In this example, an electrical connection element 5 for charging the battery 3 is provided on the body of the motor vehicle 4. As mentioned above, the climate control system 1 and / or the battery 3 can be fluidly and / or electrically connected to the powertrain 2. Advantageously, all the features and technical effects of the climate control system 1 according to the invention ensure optimal exchange of electrical energy between the battery 3 and the components of the motor vehicle 4, for example while the motor vehicle is moving or while charging while parked.

[0042] According to the present invention, the temperature regulation system 1 can advantageously be of several types. The heat transfer fluid contained in the case 8 of the module 7 can be air in gas phase or a dielectric heat transfer fluid in liquid phase, which regulates the temperature of at least some of the storage cells 9 contained in the battery 3 module 7. The battery 3 module 7 also allows the storage cells 9 to be electrically connected to other parts of the vehicle 4 for supplying electrical energy to these parts. These electrical connections are established by waterproof connectors. The battery 3 modules 7 each include a case 8 consisting of a hollow lower base 8b (receiving the storage cells 9) sealed by a top cover 8a to protect the storage cells 9 from physical incidents (such as collisions or physical shocks) and to protect them in the event of a fire (limiting the spread of flames outside the respective battery 3 module 7 and preventing the flame from reaching the storage cells 9).

[0043] According to the present invention, the temperature regulation system 1 includes a control unit 11 electrically connected to a fluid monitoring device 19 housed in the case 8 of the battery 3 module 7 for selectively controlling the function of the temperature regulation system 1 in response to diagnosed deterioration of at least one of the storage cells 9 housed in the case 8.

[0044] In the example shown in FIG. 2 illustrating a first embodiment of the present invention, the temperature regulation system 1 can be of the immersion type for the energy storage cells 9, i.e., each battery 3 module 7 includes a case 8 that houses the energy storage cells 9 in a dielectric heat transfer fluid. Preferably, the energy storage cells 9 of each battery 3 module 7 are fully immersed in the dielectric heat transfer fluid that forms part of the fluid network 6. Preferably, the battery 3 modules 7 are fluidly connected to the rest of the fluid network 6 by fluid connections with a common inlet 10 and a common outlet 12. In the example shown in FIG. 2, three battery 3 modules 7 are arranged in parallel in the fluid network 6 so that the dielectric heat transfer fluid is supplied evenly and uniformly to each battery 3 module 7, thereby achieving uniform temperature management for each energy storage cell 9. This parallel arrangement also reduces pressure losses in the fluid network 6. In order to equalize the pressure loss at each connection of the battery 3 modules 7 (i.e., to equalize the flow rate within each module), the fluid connection cross-section between the common inlet 10 and the corresponding battery 3 module 7 varies in size depending on the distance from the connection with the fluid network 6 so that the flow rate of the dielectric heat transfer fluid between each battery 3 module 7 is equal.

[0045] In the example shown in FIG. 3 , which illustrates a second embodiment of the present invention, the temperature regulation system 1 can be of the heat exchanger 18 type, which includes a heat transfer fluid surrounding the energy storage cells 9, i.e., each battery 3 module 7 includes a case 8 housing the energy storage cells 9 and the heat exchanger 18. Preferably, the energy storage cells 9 of each battery 3 module 7 are heated or cooled by the heat exchanger 18, which forms part of the fluid network 6 of the temperature regulation system 1, via the heat transfer fluid in the case 8. Preferably, the battery 3 modules 7 are fluidly connected to other parts of the fluid network 6 by hydraulic connections to a common inlet 10 and a common outlet 12. In the example shown in FIG. 3 , the battery 3 modules 7 (only one in FIG. 3 ) are arranged in parallel in the fluid network 6 so that the heat transfer fluid is supplied evenly and uniformly to each heat exchanger 18 of each battery 3 module 7, thereby achieving uniform temperature management for each energy storage cell 9. This parallel arrangement also reduces the pressure loss in the fluid network 6 between the inlet 10′ and outlet 12′ of the heat exchanger 18 in the case 8.

[0046] Therefore, it can be seen that the temperature regulation system 1 according to the present invention can maintain the temperature of the storage cells 9 at an optimum level to ensure optimal operation (maintaining the best energy efficiency) and high durability (extended service life due to optimal charging and discharging) of the battery 3 regardless of the external conditions in which the vehicle 4 is running, such as extreme cold or extreme heat.

[0047] In a simpler solution, it is conceivable to dispense with the heat exchanger 18 altogether and have a heat transfer fluid, such as air at atmospheric pressure, drawn into the case 8 by a ventilation system and expelled from the case 8 (third embodiment, not shown). It will be appreciated that in this third embodiment the heating and cooling capacity of the temperature regulation system 1 is significantly more limited than in the previous two embodiments.

[0048] Typically, the immersion example of the first embodiment provides the most efficient heat exchange because it has a larger specific exchange surface area and the circulation of the dielectric heat transfer fluid allows it to be quickly discharged outside each battery 3 module 7. This provides high efficiency and regulation, allowing for high power charging (at a quick charging station) and discharging (power consumption of the vehicle 4 under high load) of the battery. Furthermore, heat exchange is extremely effective, as it occurs directly on the casing of each storage cell 9 by convection of the heat transfer fluid. Additionally, regulation by immersion more reliably prevents the spread of fire in the event of a fire in the battery 3 of the vehicle 4.

[0049] According to the present invention, each battery 3 module 7 advantageously includes a monitoring device 19 for a characteristic other than temperature of the fluid contained in the case 8 of the module 7 in order to diagnose deterioration of at least one of the storage cells 9 contained in the case 8.

[0050] According to the present invention, it is assumed that the battery 3 is formed by a plurality of modules 7 electrically connected in parallel or series, which has several advantages. First, it is easier to regulate the temperature of a plurality of battery 3 modules 7 than an integrated unit having the same number of storage cells 9. Second, it is easier to mount a plurality of battery 3 modules 7 on a vehicle 4 than an integrated unit including the same number of storage cells 9. Furthermore, if only some of the storage cells 9 are defective, it is easier to replace the battery 3 module 7 including the defective storage cells 9 than to replace the entire battery 3. In this way, it can be understood that the defective storage cells 9 can be quickly identified because the battery 3 modules 7 to be checked are already known through the diagnosis of the monitoring device 19.

[0051] Furthermore, each battery 3 module 7 is advantageously, according to the invention, able to detect the degradation of at least one of its storage cells 9 in order to quickly stop thermal runaway of the battery 3. An obvious solution to solve the problem of thermal runaway would be to monitor the temperature of the storage cells 9. However, this is not the solution pursued by the present invention.

[0052] For example, it has been found that in order to avoid deformation of each storage cell 9, i.e., deterioration of the components surrounding each storage cell 9, an exhaust valve 21, often formed by a frangible part that breaks when a predetermined internal pressure is exceeded, is usually provided to release the excessive pressure to the outside of the storage cell 9. When the exhaust valve 21 opens in this way, the storage cell 9 will no longer function.

[0053] Based on this recognition, the present invention does not track the temperature of each storage cell 9, but rather monitors at least one characteristic other than temperature, such as the conductivity of the fluid within the battery 3 module 7, and possibly also its composition, pressure, or transparency, to identify whether a fluid, such as gas, is leaking from at least one of the storage cells 9 of the battery 3 module 7 and quickly diagnose the possibility of thermal runaway. In fact, attaching a temperature sensor to each storage cell 9 is costly and complicated, and measuring a single temperature within the case 8 does not reliably and sufficiently early detect thermal runaway in any one storage cell 9. The present invention employs an alternative method to detect an abnormality after the destruction of at least one of the storage cells 9. In this way, the location of a thermal runaway event in the battery 3 module 7 is immediately identified, well before the thermal runaway event spreads to other storage cells 9 of the battery 3 module 7 and / or other battery 3 modules 7. Furthermore, the present invention advantageously provides that the monitoring device 19 is compatible with various types of temperature control systems 1, as described above.

[0054] The monitoring device 19 comprises at least one sensing element 13 mounted on the case 8 of the module 7 for identifying the presence of a contaminated fluid leaking from at least one of the storage cells 9, different from the fluid contained in the case 8 of the battery module 7. Advantageously, according to the invention, the sensing element 13 can be mounted either inside or outside the case 8, depending on the mounting manner or type of the battery 3. Of course, to improve the diagnostic capabilities of the control unit 11, there may be several identical sensing elements 13 (sensing the same characteristic of the fluid in the battery 3 module 7) and / or different sensing elements (sensing several different characteristics of the fluid in the battery 3 module 7) on the same module 7.

[0055] According to the invention, the sensing element 13 comprises at least one conductivity sensor for measuring the change in conductivity in the fluid contained in the case 8 caused by a contaminating fluid leaking from at least one of the storage cells 9. Advantageously, according to the invention, if the change in conductivity (or conversely, resistivity) of the fluid in the battery 3 module 7 deviates from a predetermined threshold (such as the average conductivity of the other battery 3 modules 7, a deviation from a normal conductivity at a certain temperature, or a deviation from a predetermined conductivity), the monitoring device 19 can immediately diagnose a possible thermal runaway. By way of non-limiting example, the conductivity sensor can be an electrode sensor.

[0056] Conductivity sensors are preferred because they are more reliable for detecting characteristics in fluids than other characteristics. For example, conductivity sensors are less affected by other characteristics of the fluid (e.g., color, clarity, etc.) that may interfere with / alter the measurement of the characteristic. In other words, conductivity sensors produce fewer erroneous measurements than other types of sensors in the context of the present invention.

[0057] Additionally, in the special case where the fluid is air, a conductivity sensor can also detect an increase in humidity in the air, which usually leads to a short circuit (air dielectric breakdown) that precedes thermal runaway. In other words, a conductivity sensor can not only diagnose thermal runaway, but also prevent it, something that other types of sensors, such as temperature or pressure sensors, cannot do.

[0058] According to a first variant embodiment, the sensing element 13 may further comprise a concentration sensor for measuring the concentration of a contaminating fluid that has leaked from at least one of the storage cells 9 into the fluid contained in the case 8. It is understood that the presence of even a small amount of contaminating fluid is enough for the monitoring device 19 to immediately diagnose a possible thermal runaway.

[0059] According to a second variant embodiment, the sensing element 13 can further comprise a pressure sensor for measuring the change in pressure in the fluid contained in the case 8 caused by a contaminated fluid leaking from at least one of the storage cells 9. Advantageously, according to the invention, if the change in pressure of the fluid in the battery 3 module 7 exceeds a predetermined threshold (such as the average pressure of the other battery 3 modules 7, a deviation from the normal pressure at a certain temperature or a deviation from a predetermined pressure such as atmospheric pressure outside the case 8), the monitoring device 19 can immediately diagnose a possible thermal runaway.

[0060] According to a third variant embodiment, the detection element 13 can further comprise an optical sensor for measuring a change in light transmission in the fluid contained in the case 8, caused by a contaminated fluid leaking from at least one of the storage cells 9. Advantageously, according to the invention, if the change in light intensity of the fluid in the battery 3 module 7 exceeds a predetermined threshold (e.g., deviation from the average light intensity of the other battery 3 modules 7 or from a predetermined light intensity), the monitoring device 19 can immediately diagnose a possible thermal runaway. It is noted that this last type of sensor can also perform other additional detections. For example, immediately after a fire breaks out in the battery module 7, the monitoring device 19 can detect smoke by a decrease in light intensity, or conversely, flames by an increase in light intensity. Furthermore, if the dielectric heat-transfer fluid in the battery 3 module 7 is in liquid phase, the monitoring device 19 can detect gas bubbles leaking from the storage cells 9 by a change in light intensity.

[0061] According to the invention, the monitoring device 19 can advantageously comprise at least one guide element 17 attached to the case 8 for diverting contaminated fluid leaking from at least one of the storage cells 9 towards the detection elements 13, with the aim of improving the reliability of detection and limiting the number of detection elements 13. It is understood that this guide element 17 can form part of the top cover 8a of the case 8, in order to force the contaminated fluid to pass in front of each detection element 13. In this way, the guide element 17 can form a collector that forces all contaminated fluid to pass in front of each detection element 13.

[0062] As can be seen in the example shown in FIG. 3, the guide element 17 can include, for example, a deflector 16 above some of the storage cells 9 in order to force any contaminated fluid originating from any of the storage cells 9 into the detection zone 14 of the detection element 13 before being discharged in the direction of the outlet 15.

[0063] Of course, the guide element 17 can simply force all contaminated fluids from any of the storage cells 9 to be discharged in the direction of the outlet 15, so that they pass outside the case 8 of the module 7 and preferably through the detection zone 14 of the detection element 13 located near the outlet 15.

[0064] The present invention is not limited to the embodiments and variants presented, and other embodiments and variants will be obvious to those skilled in the art. Therefore, the embodiments and variants can be combined with each other without departing from the framework of the present invention. Without being limited thereto, other types of sensing elements 13 capable of detecting contaminating fluid from one of the storage cells 9 can also be used without departing from the framework of the present invention. It should be noted that a temperature sensing element T02 can be used to thermally weight sensors such as pressure sensors and / or conductivity sensors. [Explanation of symbols]

[0065] 1. Temperature control system 2 Powertrain 3 Battery 4. Automobiles 5 Electrical connection elements 6 Fluid Networks 7 Battery Module 8 Battery module case 8a Case top cover 8b Hollow lower base of case 9 Energy storage cells 10 Common inflow channel 10' entrance 11 Control Unit 12 Common outflow channel 12' exit 13. Sensing Elements 14 Detection Zone 15 Contaminated fluid outlet 16 Deflector 17 Guidance Elements 18 Heat exchanger 19 Monitoring equipment 21 Exhaust valve T02 Module temperature sensing element

Claims

1. 1. A battery module (7) for a vehicle (4) including a case (8) containing storage cells (9), the battery module (7) comprising: a monitoring device (19) for monitoring a characteristic of a fluid contained in the case (8) of the module (7) to diagnose thermal runaway of at least one of the storage cells (9) contained in the case (8) of the module (7); the monitoring device (19) includes at least one sensing element (13) mounted on the case (8) of the module (7) for identifying the presence of a gaseous contaminant fluid that has leaked from at least one of the storage cells (9), the gaseous contaminant fluid being different from the fluid contained in the case (8) of the module (7); and the sensing element (13) includes a conductivity sensor for measuring a change in conductivity in the fluid contained in the case (8) of the module (7) caused by the gaseous contaminant fluid leaking from at least one of the storage cells (9).

2. 2. The battery module (7) of claim 1, wherein the sensing element (13) further includes a concentration sensor for measuring the concentration of a gaseous contaminant fluid leaked from at least one of the storage cells (9) into the fluid contained in the case (8) of the module (7).

3. 2. The battery module (7) of claim 1, wherein the sensing element (13) further comprises a pressure sensor for measuring a change in pressure within the fluid contained in the case (8) of the module (7) caused by the gaseous contaminant fluid leaking from at least one of the storage cells (9).

4. 2. The battery module (7) of claim 1, wherein the sensing element (13) further comprises an optical sensor for measuring a change in light transmission within the fluid contained in the case (8) of the module (7) caused by the gaseous contaminant fluid leaking from at least one of the storage cells (9).

5. 5. The battery module (7) according to claim 1, wherein the monitoring device (19) includes at least one guide element (17) attached to the case (8) of the module (7) for diverting the gaseous contaminant fluid leaking from at least one of the storage cells (9) toward the detection element (13) in order to improve detection reliability and reduce the number of the detection elements (13).

6. 5. A battery (3) module (7) according to any one of claims 1 to 4, wherein the sensing element (13) is mounted inside the case (8) of the module (7).

7. 5. The battery (3) module (7) according to any one of claims 1 to 4, wherein the sensing element (13) is mounted externally to the case (8) of the module (7).

8. 5. The battery module (7) according to claim 1, wherein the fluid contained in the case (8) of the module (7) is air.

9. 5. The battery (3) module (7) according to claim 1, wherein the fluid contained in the case (8) of the module (7) is a liquid-phase dielectric heat-conducting fluid that regulates the temperature of at least some of the storage cells (9) included in the battery (3) module (7).

10. 5. A temperature regulation system (1) for a battery (3) module (7) for a motor vehicle (4) according to any one of claims 1 to 4, characterized in that it comprises a control unit (11) electrically connected to the monitoring device (19) for the fluid housed in the case (8) of the module (7) for selectively controlling the function of the temperature regulation system (1) in response to diagnosed deterioration of at least one of the storage cells (9) housed in the case (8) of the module (7).

11. A motor vehicle (4) comprising a climate control system (1) according to claim 10.

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