Module for an electric vehicle

Abstract

The invention relates to an electric module (1) comprising: - a plurality of electric cells (2) comprising electrodes separated from one another by a porous separator film and an electrolyte, the electric cells (2) each comprising a ventilation device (3) capable of allowing a gas produced inside the cells (2) to be discharged, - a temperature control support (4) in contact with the electric cells (2), the temperature control support (4) being capable of regulating the temperature of the electric cells (2), the module (1) comprising a discharge channel (5) capable of discharging, outside the module (1), the gases produced by the cells (2), the discharge channel (5) being delimited on the one hand by the support (4) and on the other hand by the cells (2), in which module (1) the cells (2) are arranged such that the ventilation device (3) of the cells (2) opens into the discharge channel (5).

Description

Module for electric vehicle Technical field of the invention

[0001] The invention relates to the field of rechargeable electric batteries for electric motor vehicles. In particular, the invention relates to modules comprising a plurality of electric cells. Technical background

[0002] The electric battery intended to equip electric vehicles comprises several electrical modules, themselves comprising numerous electrical cells.

[0003] For optimal operation, the cells are maintained within a predetermined temperature range.

[0004] Thus, the thermal management of cells can consist of cooling the cells or, on the contrary, heating them.

[0005] Thermal management of cells in a module is therefore a major issue.

[0006] Various factors, alone or in combination, can cause electrical cells to reach a point of no return temperature. Once this threshold temperature is reached, the cell begins a self-heating process, during which its temperature increases uncontrollably.

[0007] Once this temperature is reached, the cell will inevitably self-destruct. This is thermal runaway. In a state of thermal runaway, the cell will begin to burn up. An explosion is likely to occur, causing neighboring cells to explode, and so on.

[0008] This situation represents a real danger for the occupants of the vehicle.

[0009] The vehicle's passengers may be seriously injured or even killed.

[0010] Early detection of such a situation is therefore a major issue, since it allows the occupants of the motor vehicle to be saved, giving them time to get to safety.

[0011] In a situation of thermal runaway, an initial outgassing occurs.

[0012] Another problem lies in the high temperature of the gases that are ejected from the cells in a situation of thermal runaway.

[0013] The temperature of the gases is typically above 1000°C. This temperature can cause considerable material damage that could endanger the occupants of the vehicle.

[0014] Another drawback concerns environmental pollution from gases ejected from the cells. These gases are likely to cause environmental pollution.

[0015] The invention aims to improve the safety of electrical modules.

[0016] To this end, it is proposed firstly an electrical module comprising: - a plurality of electrical cells having electrodes separated from each other by a porous separating film and an electrolyte, said electrical cells each comprising a ventilation device capable of allowing the evacuation of a gas produced inside said cells, - a thermoregulation support in contact with the electrical cells, said thermoregulation support being capable of regulating the temperature of said electrical cells, the module comprising an evacuation channel capable of evacuating outside the module the gases produced by the cells, said channel being delimited on one side, by the support and on the other, by the cells, module in which the cells are arranged so that the ventilation device of said cells opens into the evacuation channel, module in which the latter comprises a dielectric fluid,said module being configured so that the gases flowing in the exhaust channel are brought into contact with said dielectric fluid.

[0017] Thus, in the event of thermal runaway, the gas ejected from the cells is vented through the exhaust channel. The presence of a dielectric fluid in contact with the ejected gases allows for faster cooling of these gases. Furthermore, the dielectric fluid captures certain pollutants present in the gases. As a result, the ejected gases are cooled and purified more effectively. Passenger safety is improved and pollution is reduced.

[0018] Various additional features may be provided alone or in combination: - the module includes at least one temperature sensor capable of measuring the temperature in the exhaust channel; - the module includes at least one pressure sensor capable of measuring the pressure in the exhaust channel; - at least one temperature sensor is capable of measuring the temperature of the support in the exhaust channel, and / or of a gas in the exhaust channel, and / or of a dielectric fluid in the exhaust channel; - at least one pressure sensor is capable of measuring the pressure of a gas in the exhaust channel or of a dielectric fluid in the exhaust channel; - in the exhaust channel, the support is arranged at a distance from the cell ventilation device of at least 5 millimeters; - the support includes at least one thermoregulation channel capable of regulating the temperature of the cells;- the module includes a thermoregulation channel arranged on either side of the discharge channel; - includes a computer management device capable of receiving temperature measurements from at least one temperature sensor and / or pressure measurements from at least one pressure sensor, said management device being capable of thermoregulating said electrical cells and / or disconnecting said electrical cells; - the dielectric fluid is static.

[0019] Secondly, a management process is proposed implementing a module as previously described, said process includes: - a step of measuring the pressure in the discharge channel, and / or - a step of measuring the temperature in the discharge channel, when the temperature in the discharge channel reaches a predetermined threshold, the process includes a step of modifying the temperature of the heat transfer fluid and / or a step of disconnecting at least one electrical cell and / or a step of varying the electrical current of the electrical cells.

[0020] This process allows for the detection of variations in pressure and / or temperature. It is therefore possible to detect an initial outgassing.

[0021] Various additional features can be provided alone or in combination: - the temperature measurement in the evacuation channel is carried out by measuring the support and / or a dielectric fluid present in the evacuation channel or present in a tank connected to the evacuation channel and / or a gas evacuated by a ventilation device. Brief description of the figures

[0022] Other features and advantages of the invention will become apparent upon reading the detailed description that follows, for which reference should be made to the attached drawing in which:

[0023] laest a schematic representation of a portion in section of a module according to the invention. Detailed description of the invention

[0024] Figure 1 shows an electrical module comprising electrical cells 2. Each electrical cell 2 includes electrodes separated from each other by a porous separator film. Each cell 2 contains an electrolyte. Each cell 2 includes a ventilation device 3. The ventilation device 3 allows the evacuation of a gas generated inside cell 2 to the outside.

[0025] Module 1 includes a thermoregulation support 4. This support is in direct contact with the electrical cells 2. The thermoregulation support 4 is capable of regulating the temperature of the electrical cells 2. This regulation can be either increased or decreased to maintain the cells 2 within an optimal operating temperature range. In practice, its primary function is to cool the cells 2.

[0026] Module 1 includes a gas exhaust channel 5. This exhaust channel 5 is designed to vent the gases generated by cell 2. The exhaust channel 5 is configured to vent the gases outside of module 1. Thus, as can be seen in the diagram, the ventilation device 3 opens into the exhaust channel 5.

[0027] The evacuation channel 5 is in the form of a conduit delimited by the thermoregulation support 4 on one side and by the cells 2 themselves on the other side.

[0028] Module 1 includes a dielectric fluid. Module 1 is configured so that in the event of gas ejection into the discharge channel 5, said gas is brought into contact with the dielectric fluid.

[0029] Thus, in the event of thermal runaway, the gas ejected from cells 2 is evacuated via the exhaust channel 5. The presence of a dielectric fluid in contact with the gases ejected from cells 2 allows for faster cooling of said gases. Furthermore, the dielectric fluid captures certain pollutants present in the gases. As a result, the ejected gases can be cooled and decontaminated more effectively. Passenger safety is improved and pollution is reduced.

[0030] In the non-limiting embodiment shown in Figure 2, the electrical cells 2 are of the "prismatic" type. A prismatic cell comprises a rigid outer casing defining a housing in which the electrodes are arranged, separated by a porous separator film. The cell 2 includes a cover 6 in which the ventilation device 3 is arranged.

[0031] Advantageously, module 1 includes at least one temperature sensor. The temperature sensor is suitable for measuring the temperature in the discharge channel 5.

[0032] By using a temperature sensor to measure the temperature in the exhaust duct, and because the gases are in contact with a dielectric liquid, temperature detection can occur very early. The contact of the gases with the dielectric liquid allows for the detection of even the slightest upward temperature increase. This makes it possible to detect the first outgassing.

[0033] Advantageously, module 1 includes at least one pressure sensor. The sensor is arranged to measure the pressure in the discharge channel.

[0034] The pressure sensor can detect a pressure variation in the discharge channel, and thus provide information on the occurrence of degassing.

[0035] In combination with the temperature sensor, pressure and temperature measurements increase the reliability of detection and allow for early detection of initial outgassing.

[0036] Advantageously, in the evacuation channel 5, the temperature of the support, and / or of a gas and / or of a dielectric fluid present in said channel, is measured by the temperature sensor.

[0037] Temperature measurement can be performed in various ways. In one embodiment, the temperature sensor is capable of measuring the temperature of the substrate in the drainage channel. By way of non-limiting example, the temperature sensor is thus arranged in direct contact with the substrate.

[0038] Thus, a temperature variation of the support indicates the occurrence of outgassing.

[0039] In another embodiment, the temperature sensor is capable of measuring the temperature in the drainage channel. By way of non-limiting example, the measurement can be taken at at least one end of the drainage channel.

[0040] Such a measurement makes it possible to detect a temperature variation in the evacuation channel and thus determine the occurrence of degassing.

[0041] In another embodiment, the temperature sensor is capable of measuring the temperature of a dielectric fluid. The discharge channel can thus be fluidically connected to a reservoir containing a dielectric fluid, or the fluid can be placed directly in the discharge channel. The dielectric fluid cools the gases. Furthermore, the fluid traps harmful elements or at least reduces their concentration before discharge from the module.

[0042] Such a measurement of a dielectric fluid makes it possible to detect the occurrence of outgassing.

[0043] According to one embodiment, at least two of the previously mentioned temperature measurements are combined.

[0044] Thus, the reliability of detection is improved.

[0045] Advantageously, in the discharge channel 5, the pressure of a gas and / or dielectric fluid is measured by at least one of the pressure sensors.

[0046] Pressure measurement can be carried out in different ways. In one embodiment, the pressure sensor is suitable for measuring the pressure of a gas in the discharge channel.

[0047] Such a measurement makes it possible to detect a pressure variation in the evacuation channel 5 and identify a degassing.

[0048] According to one embodiment, the pressure sensor is capable of measuring the pressure of the dielectric fluid.

[0049] This measure allows for the detection of outgassing in the exhaust channel 5. In the exhaust channel 5, the support 4 is positioned at a predetermined distance 7 from the cell ventilation device 3. The distance 7 separating the support from the ventilation device is at least 5 millimeters. This distance 7 is measured along the shortest path from any point on the support 4 towards the ventilation device 3.

[0050] This distance of 7 ensures the mechanical integrity of the vent channel 5 during degassing. In other words, during the degassing of cell 2, the vent channel 5 will not be damaged and will remain operational for any subsequent degassing operations.

[0051] Advantageously, the temperature of cells 2 is regulated by at least one thermoregulation channel 8. As can be seen in the figure, the thermoregulation channel 8 is arranged in the support 4 of module 1. The support 4 includes a thermoregulating wall 9 arranged in direct contact with cells 2. Thus, the heat transfer fluid is not in direct contact with cells 2.

[0052] The thermoregulation channel 8 allows the temperature of cell 2 to be regulated and prevents thermal runaway of cell 2.

[0053] Advantageously, module 1 includes a thermoregulation channel 8 arranged on either side of the exhaust channel 5.

[0054] This allows the temperature of cells 2 to be regulated.

[0055] Advantageously, module 1 is equipped with a computer control unit (not shown in the drawings). The control unit receives temperature and pressure information measured by at least one of the temperature and / or pressure sensors. The computer control unit is capable of regulating the temperature of cells 2. This temperature regulation can, for example, be achieved by acting on the temperature of the temperature control channels 8. The computer control unit can also disconnect electrical cells 2 if a risk of thermal runaway is detected. The computer control unit can also vary the electrical current of the electrical cells 2.

[0056] The computer management system allows the module 1 to be secured. By receiving and then analyzing temperature and / or pressure data, the computer management system can detect early degassing in the evacuation channel 5 and thus put in place the securing of module 1, by thermoregulation of cells 2 and / or disconnection of said cells 2 and / or by variation of the electrical current of said cells 2.

[0057] The computer management system helps to contain the spread of thermal runaway in module 1. Disconnecting the faulty cell 2 reduces the risk of fire and explosion. Furthermore, it prevents damage to other components of the module.

[0058] Advantageously, the dielectric fluid is static. By "static" it is understood that the dielectric fluid is stationary.

[0059] The dielectric fluid is static in order to improve the reliability of early outgassing detection in cell 2. The fact that the dielectric fluid is static allows for more reliable detection of even the slightest change in temperature or pressure.

[0060] The following will describe a management process implementing a module 1 as previously described.

[0061] According to one embodiment, the process includes a step of measuring the pressure in the discharge channel 5.

[0062] According to another embodiment, the process includes a step of measuring the temperature in the discharge channel 5.

[0063] According to one variant of the embodiment, pressure and temperature measurements in the discharge channel 5 are carried out in combination.

[0064] This process detects variations in pressure and / or temperature. It is thus possible to detect initial outgassing. When the temperature and / or pressure reaches or exceeds a predetermined value, the process comprises various steps carried out individually or in combination.

[0065] According to one embodiment, the process includes a step of reducing the temperature of the heat transfer fluid circulating in the thermoregulation channels 8.

[0066] By lowering the temperature, thermal runaway can be delayed or even avoided.

[0067] According to another embodiment, the process includes a step of disconnecting at least one defective electrical cell 2.

[0068] Disconnecting cells 2 prevents thermal runaway of said cells 2.

[0069] According to another embodiment, the process includes a step of varying the electric current of the 2 electric cells.

[0070] The variation of the electric current on one or more given cell(s) 2 can prevent a thermal runaway.

[0071] According to one embodiment, the process performs in combination at least two of the previously mentioned steps.

[0072] Thus, thermal runaway can be avoided.

[0073] According to one embodiment, the temperature measurement is carried out directly on the support 4.

[0074] According to another embodiment, the measured temperature is that of the dielectric fluid present in the discharge channel or in a reservoir fluidically connected to the discharge channel.

[0075] According to another embodiment, the measured temperature is that of the gas ejected into the discharge channel 5.

[0076] These temperature measurements make it possible to detect the occurrence of early outgassing of an electrical cell 2.

Claims

Electrical module (1) comprising: - a plurality of electrical cells (2) having electrodes separated from each other by a porous separating film and an electrolyte, said electrical cells (2) each comprising a ventilation device (3) adapted to allow the evacuation of a gas produced inside said cells (2), - a thermoregulation support (4) in contact with the electrical cells (2), said thermoregulation support (4) being adapted to regulate the temperature of said electrical cells (2), the module (1) comprising an evacuation channel (5) adapted to evacuate outside the module (1) the gases produced by the cells (2), said evacuation channel (5) being delimited on one side by the support (4) and on the other side by the cells (2), module (1) in which,The cells (2) are arranged so that the ventilation device (3) of said cells (2) opens into the discharge channel (5) of module (1) in which the latter comprises a dielectric fluid, said module (1) being configured so that the gases circulating in the discharge channel (5) are brought into contact with said dielectric fluid. Module (1) according to claim 1 wherein, it comprises at least one temperature sensor capable of measuring the temperature in the discharge channel (5). Module (1) according to any one of claims 1 or 2 wherein it comprises at least one pressure sensor capable of measuring the pressure in the discharge channel (5). Module (1) according to any one of claims 2 or 3 wherein at least one temperature sensor is capable of measuring the temperature of the support (4) in the discharge channel (5), and / or of a gas in the discharge channel (5), and / or of a dielectric fluid in the discharge channel (5). Module (1) according to claim 4 further dependent on claim 3 in which at least one pressure sensor is capable of measuring the pressure of a gas in the discharge channel (5) or of a dielectric fluid in the discharge channel (5). Module (1) according to any one of claims 1 to 5 wherein, in the discharge channel (5), the support (4) is arranged at a ventilation distance (7) from the cell ventilation device (3) (2) of at least 5 millimeters. Module (1) according to any one of the preceding claims in which the support (4) comprises at least one thermoregulation channel (8) capable of regulating the temperature of the cells (2). Module (1) according to claim 7 wherein, it comprises a thermoregulation channel (8) arranged on either side of the evacuation channel (5). Module (1) according to claim 8 and according to claim 7 further dependent on claim 2 and / or 3 wherein it comprises a computer management device capable of receiving temperature measurements from at least one temperature sensor and / or pressure measurements from at least one pressure sensor, said management device being capable of thermoregulating said electrical cells (2) and / or disconnecting said electrical cells (2). Module (1) according to any one of the preceding claims in which, the dielectric fluid is static. A management method implementing a module (1) according to claim 2 and according to any one of claims 3 to 10 further dependent on claim 2, wherein it comprises: - a step of measuring the pressure in the discharge channel (5), and / or - a step of measuring the temperature in the discharge channel (5), when the temperature and / or pressure in the discharge channel (5) reaches a predetermined threshold, the method comprises a step of modifying the temperature of the heat transfer fluid and / or a step of disconnecting at least one electrical cell (2) and / or a step of varying the electrical current of the electrical cells (2). Method according to claim 11 wherein the temperature measurement in the discharge channel (5) is carried out by measuring the support (4) and / or a dielectric fluid present in the discharge channel (5) or present in a reservoir connected to the discharge channel (5) and / or a gas discharged by a ventilation device (3).

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