FR3140662A1 - BREATHING VALVE SYSTEM WITH OVERPRESSURE PROTECTION - Google Patents

Abstract

The invention relates to a breathing valve (100) for an energy storage device in electrochemical form, this device comprising an envelope (30), this valve itself comprising: - a valve body (1); - a membrane support (4) for supporting a membrane allowing circulation between an exterior atmosphere (Ve) and the interior atmosphere (Vi) at the valve; - means (8, 10) forming a valve for opening and closing the valve; - activation means (12, 14) for activating the means forming a valve between a first position, called opening, of the valve and a second position, called closing of the valve, these activation means authorizing, in said first position, the circulation between the interior atmosphere and the atmosphere exterior to the valve, and closing, in said second position, said circulation. Figure for abstract: figure 1

Description

BREATHING VALVE SYSTEM WITH OVER-PRESSURE PROTECTION TECHNICAL FIELD AND PRIOR ART

The invention relates to the field of energy storage means, in particular of the type used in vehicles, for example of the type for moving materials and/or people, these storage means implementing solutions of the type electrochemical.

The invention relates in particular to an application linked to batteries, in particular lithium-ion batteries, which consist of a sealed envelope comprising a set of unit cells and most of the time electronic and power components for their interconnection and control. Now essential, battery technologies are seeing their energy density increase and their architecture evolve.

Generally speaking, electrochemical storage means, for example fuel cells, must be impervious to water and dust, for example, but be able to exchange a certain quantity of air with the ambient environment, and this in both direction, in order to balance the pressure. This makes it possible to reduce the constraints on the envelope which contains these storage means, to facilitate transport and to ensure optimal use whatever the external conditions (temperature and pressure).

A particular problem is that of possible overpressures, for example induced in the case of thermal runaway or by combustion gases. Such overpressures can lead to bursting of the casing, for example of a battery pack.

The problem therefore arises of finding a system or device allowing respiration, or balancing, for example of the pressure and/or the temperature and/or another thermodynamic parameter, between the interior atmosphere of 'an envelope of an electrochemical type storage assembly and the external atmosphere of this envelope, this system or this device benefiting from protection in the event of overpressures internal to the envelope.

This problem arises in particular in the case of a modular energy storage system, in which one or more modules can be added or removed in order to vary the storage capacity of the assembly.

The invention firstly relates to a valve, or breathing valve, for an enclosure or an envelope of an energy storage device, for example in electrochemical form, for example a battery, for example also a lithium type battery. – ion, this valve itself comprising:

- a valve body;

- a membrane support for supporting a membrane allowing circulation between an exterior atmosphere (V _e ) and the interior atmosphere (V _i ) at the valve or envelope;

- means forming a flap for opening and closing the valve;

- activation means, for activating the means forming a valve between a first position, called opening, of the valve and a second position, called closing of the valve. For example, these means allow:

- to authorize, in said first position, circulation between the interior atmosphere and the atmosphere exterior to the valve, for example when a pressure and/or a temperature, called reference, for example equal to the pressure and/or or the temperature of the interior atmosphere, or the difference in pressure and/or temperature between the interior atmosphere and the exterior atmosphere, or the variation in pressure and/or temperature of the interior atmosphere and/or of the external atmosphere, for example for a predetermined duration, is lower than a pressure and/or temperature limit value,

- and/or to close, in said second position, said circulation, for example when the pressure and/or temperature, called reference, is greater than said pressure and/or temperature limit value.

The invention also relates to a valve, or breathing valve, for an enclosure or an envelope of an energy storage device in electrochemical form, for example a battery, for example also a lithium-ion type battery, this valve comprising itself:

- a valve body;

- a membrane support for supporting a membrane allowing circulation between an exterior atmosphere (V _e ) and the interior atmosphere (V _i ) at the valve or envelope;

- means forming a valve. For example, these means forming a valve allow:

* to authorize, in a first position, called the opening position, circulation between the interior atmosphere and the atmosphere exterior to the valve, for example when a pressure and/or temperature, called reference, for example equal to the pressure and/or temperature of the interior atmosphere or to the difference in pressure and/or temperature between the interior atmosphere and the exterior atmosphere, or to the variation in pressure and/or temperature of the atmosphere interior and/or the exterior atmosphere, for example for a predetermined duration, is lower than a pressure and/or temperature limit value,

* and/or to close, in a second position, called the closing position, said circulation, when the pressure and/or the temperature, called the reference, is greater than said pressure and/or temperature limit value.

In other words, the invention relates to a breathing valve which can be closed, for example in the case of overpressure and/or heating of the atmosphere inside the valve or an enclosure provided with this valve; the invention also relates to a method of controlling or operating such a valve.

Examples of opening or closing of the valve according to the invention or of a process according to the invention, under the action of pressure and/or temperature and/or, more generally, of a thermodynamic parameter , or differences in pressure and/or temperature and/or the thermodynamic parameter or a variation in pressure and/or temperature and/or the thermodynamic parameter, mentioned above and in the remainder of this description are not not limiting: a valve according to the invention a method according to the invention can also be controlled in opening and closing under the action, for example, of detection of a variation in temperature and/or a variation in pressure or under an external action, for example from an operator who wishes to open or close the valve and/or in the case of a variation in voltage which exceeds a threshold value and/or a voltage that is too low or too high, that is to say less than a ^1st limit value or greater than a ^2nd limit value, this voltage being measured at the terminals of an energy storage device, or being the voltage supplied by such energy storage device, equipped with the valve.

More generally, in a valve according to the invention or in a process according to the invention, the activation means or the means forming a valve can:

- authorize, in said first position, circulation between the interior atmosphere and the atmosphere exterior to the valve, when at least one thermodynamic parameter of the interior atmosphere or the difference in a thermodynamic parameter between the interior atmosphere and the external atmosphere, or its variation, for example over a predetermined duration, is less than a limit value;

- and/or close, in said second position, said circulation, for example when said thermodynamic parameter, or its difference between the interior atmosphere and the exterior atmosphere, or its variation, for example during said predetermined duration, is greater ) to said limit value.

According to an example, already mentioned above, said at least one thermodynamic parameter, or its difference between the interior atmosphere and the exterior atmosphere, comprises at least the pressure and/or the temperature of the interior atmosphere and/or of the exterior atmosphere, or the difference in pressure and/or temperature between the interior atmosphere and the exterior atmosphere and/or a variation in pressure (or pressure difference) and/or temperature (or temperature difference ) of the interior atmosphere and/or the exterior atmosphere (or between the interior atmosphere and exterior atmosphere).

In a valve or in a method according to the invention, the means forming a valve can, in the closed position, come to bear against an interior part of the body of the valve, for example when at least one thermodynamic parameter has a value greater than a limit value, for example when the pressure and/or temperature, called reference, is for example greater than the pressure and/or temperature, limit or for example when the difference in temperature and pressure is greater than a value limit.

According to one embodiment, in a valve or in a process according to the invention:

- the means forming a valve comprise a piston.

- and/or the means forming a valve may comprise a part in contact with the interior atmosphere of the valve and a part in contact with the exterior atmosphere of the valve;

- and/or the means forming a valve can move over a limited stroke, in the first position, by a stop.

This stop can be located on the interior side of the valve, or on the exterior side of the valve.

A valve according to the invention, or the means for activating the valve of a valve according to the invention, may/may comprise, or a method according to the invention may implement, means for constraining the means forming a valve in open position, for example up to a limit pressure. For example, these means for constraining the means forming a valve may comprise a spring bearing on the one hand against the means forming a valve and on the other against the membrane support.

According to a particular embodiment, the means forming a valve according to the invention, or implemented within the framework of a method according to the invention, comprise an axis which penetrates into a central extension of the membrane support; preferably, this axis reaches and is in contact with the external atmosphere of the valve. This allows the means forming a valve to be truly sensitive to a difference, for example in pressure, between the interior atmosphere and the exterior atmosphere of the valve.

In a valve according to the invention, or in the context of a method according to the invention, the activation means may for example comprise an actuator and means for moving the means forming a valve.

For example, a valve, or a valve controlled or controlled by a method according to the invention, may comprise, or be associated with, at least one pressure sensor and/or at least one temperature sensor and/or at least one sensor voltage, to measure at least one pressure and/or at least one temperature and/or at least one voltage of the device or of an energy storage device, for example at the terminals of this energy storage device and/ or a voltage supplied by it, or a variation of this pressure and/or this temperature, internal to the valve and/or external to the valve and/or of this voltage; possibly, means, for example one or more connection(s) between said at least one such sensor and an actuator as mentioned above to provide the latter with at least one piece of pressure and/or temperature information, external to the valve and/or at least one piece of pressure and/or temperature information, internal to the valve and/or at least one piece of voltage information, for example from the device or an energy storage device, measured at the terminals of it or provided by it. The actuator can therefore be controlled by signals coming from one or more pressure and/or temperature and/or voltage sensors, for example external(s) and/or internal(s) to the valve or to the valve. envelope which is fitted with this valve. According to one embodiment, at least one pressure sensor and/or at least one temperature sensor is provided inside the valve and/or at least one pressure sensor and/or at least one temperature sensor is provided inside the valve. the exterior of the valve and/or at least one voltage sensor is provided and/or a method according to the invention implements one or more of said sensors.

The means for moving the means forming a valve may comprise mechanical means for driving the means forming a valve. For example, the actuator means actuate a rod or a bar mechanically linked to the valve means, for example to the piston or to the rod which extends it.

Alternatively, the means for moving the means forming a valve comprise magnetic or electromagnetic means for driving the means forming a valve. The means forming a valve can be extended by a shaft or a rod of which at least one part is magnetized; this part can interact with said magnetic or electromagnetic means. The actuator means then comprise at least one magnetic part which drives the valve means or the shaft or rod which extends them.

The invention also relates to an enclosure or a device for storing energy in electrochemical form, for example a battery, for example also a lithium-ion battery, comprising an envelope containing one or more energy storage elements, for example a or several battery packs, this envelope being provided with a breathing valve according to the invention.

Such an enclosure may further comprise an evacuation valve which allows exhaust from the interior atmosphere to the exterior atmosphere of the envelope, in particular when the valve according to the invention is in its closed position, for example when the pressure and/or the reference temperature is greater than the pressure and/or the limit temperature, the valve means of the breathing valve then closing the circulation of atmosphere therethrough.

A storage enclosure according to the invention may comprise a plurality of energy storage elements, each element being arranged in a module separated from each of the neighboring modules by a wall, at least one of said walls being provided with a valve. breathing according to the invention. For example, each of said walls is provided with such a breathing valve according to the invention. Thus, it is possible to achieve a balance between the atmosphere of a module and that of at least one neighboring module.

In such a storage enclosure, each module can be provided with an evacuation valve which allows escape from the interior atmosphere of each module to the exterior atmosphere of the envelope when a thermodynamic parameter, for example such as described above, is greater than a limit value.

According to a variant of such a storage enclosure, each module can be connected to the external atmosphere by at least one connection channel. Thus, the breathing valve according to the invention of each module makes it possible to balance the atmosphere between the interior of each module and the exterior atmosphere of the storage enclosure.

A valve according to the invention, or a valve controlled or controlled by a method according to the invention, or a valve mounted on or in a storage enclosure according to the invention, may be associated with, or comprise, in addition, means to detect a failure in one or the energy storage device or in the storage enclosure. Such a failure may consist of the detection of an abnormal temperature and/or pressure within the device and/or a voltage of the device or of the energy storage enclosure or of a or several energy storage elements that it or it contains, and/or in the detection of an abnormal variation of one of these parameters. These means may include one or more temperature and/or pressure and/or voltage sensors, for example as already explained above. The invention also relates to a vehicle, for example for transporting people and/or goods, comprising for example a passenger compartment and/or a storage area, which can for example accommodate one or more passengers and/or goods, an engine, and at least one energy storage enclosure according to the invention, the breathing valve being in fluid communication with the passenger compartment and/or the storage zone; if, in addition, the enclosure is provided with an evacuation valve, then the latter allows gas to escape outside the passenger compartment and/or the storage area.

Such a vehicle is for example an automobile or a truck or an airplane or a construction machine, for example an excavator or a backhoe, the engine possibly being a heat engine or an electric motor or a hybrid engine.

Such a vehicle can be for example:

- of the type for transporting people and/or goods;

- and/or autonomous type;

- and/or type of motor vehicle and/or construction vehicles, for example of the excavator or backhoe type, or of the aircraft type or of the space type, or of the type used in the maritime sector, for example boat or vessel or craft or submarine, or of the type used in the railway sector, for example locomotive or wagon, more generally of the type used as an air or land or maritime locomotion vehicle.

The invention also relates to a method of operating or controlling activation of a valve or an energy storage enclosure according to the invention.

In particular, the invention also relates to a method of operating or controlling or activating a valve, or breathing valve, for example an enclosure of an energy storage device in electrochemical form, comprising a envelope, this valve, for example as explained above according to the present invention, itself comprising:

- a valve body;

- a membrane support for supporting a membrane allowing circulation between an exterior atmosphere (V _e ) and the interior atmosphere (V _i ) at the valve,

- means forming a flap for opening and closing the valve;

process in which

- the means forming a valve, authorize, in a first position, the circulation between the interior atmosphere and the atmosphere interior to the valve, and close, in a second position, said circulation,

- or else activation means activate the means forming a valve between a first position, called opening, of the valve and a second position, called closing of the valve, these activation means authorizing, in said first position, the circulation between the interior atmosphere and the atmosphere exterior to the valve, and close, in said second position, said circulation, for example when the reference pressure and/or temperature is greater than the pressure limit value and/or of temperature.

The invention also relates to a method of controlling a valve according to the invention, for example as described above or in the present application, or for example an energy storage enclosure according to the invention, by example as described above or in the present application, or of a vehicle according to the invention, for example as described above or in the present application, this method comprising the activation of the means forming a valve between a first position, called opening, of the valve and a second position, called closing position of the valve, these means of activation:

- authorizing, in said first position, circulation between the interior atmosphere and the atmosphere exterior to the valve,

- and/or closing, in said second position, said circulation.

For example, in a method according to the invention, the means forming a valve, or their activation means:

- authorize, in a first position, circulation between the interior atmosphere and the interior atmosphere of the valve, for example when a pressure and/or a temperature, called reference, equal to the pressure and/or temperature of the valve the interior atmosphere or the pressure and/or temperature difference between the interior atmosphere and the exterior atmosphere is less than a limit pressure and/or temperature value;

- and/or close, in a second position, said circulation, for example when the reference pressure and/or temperature is greater than the limit pressure and/or temperature value.

Alternatively, a method according to the invention may include the activation of said activation means by an operator, for example in the context of a maintenance or test operation of the valve.

In the context of a storage enclosure according to the invention, which may for example comprise a plurality of energy storage elements, each element being arranged in a module separated from each of the neighboring modules by a wall, at least one of said walls being provided with a breathing valve according to the invention, or with a method of operating or controlling or controlling such an enclosure, it is possible to isolate the module provided with the valve according to the invention from the neighboring module with which this valve communicates. If each wall is equipped with such a valve, each module can be isolated from its neighbors in the event of detection of an anomaly based on the detection of an abnormal value, or an abnormal variation, of one and/or or another of the parameters already mentioned above or later in this description.

The valve controlled or activated by a method according to the invention may have one or other of the characteristics set out above in connection with the valve according to the invention.

A method according to the invention can be very advantageously implemented in an energy storage enclosure, in particular an energy storage enclosure according to the present invention, for example as described above, and/or in a vehicle, for example for transporting people and/or goods, in particular according to the present invention, for example as described above.

The invention makes it possible to overcome balancing problems, for example pressure and/or temperature, of the assembly comprising energy storage elements, for example one or more batteries or battery packs. In the event of internal overpressure, and/or internal heating, resulting from an increase in the pressure and/or temperature of one or more storage elements, for example a battery pack, a valve according to the The invention allows gas exchange to be blocked. Overpressurized and/or overheated gases may possibly be evacuated through one or more evacuation valve(s). The same applies in the event of detection of an abnormal level of a parameter such as for example the voltage across an energy storage device according to the invention or supplied by such a device, or of a abnormal variation of said parameter, for example of said voltage level.

represents an exemplary embodiment of a breathing valve according to the invention in the open position;

represents an exemplary embodiment of a breathing valve according to the invention in the closed position;

And represent an enclosure of a valve according to the invention, for which the piston stop is located outside the valve body.

And represent an enclosure of a valve according to the invention, provided with an actuator for the valve protection valve.

And represent an enclosure of a valve according to the invention, provided with a magnetic actuator for the protection valve of the valve.

represents an enclosure of an energy storage device comprising a valve according to the invention as well as an evacuation valve.

And represent an application of the invention to a battery system comprising cells assembled into modules.

- represent various vehicles or machines, automobile, plane, boat, locomotive, equipped with an energy storage device comprising a valve according to the invention as well as an evacuation valve.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

Figures 1 and 2 represent an exemplary embodiment of a valve 100 according to the invention.

It comprises a fixed body 1 placed in a dedicated orifice of the envelope 30 of an energy storage device in electrochemical form, for example a battery pack.

In this example, this body has a symmetry of revolution around an axis AA’. But other shapes can be made, for example we can have a rectangular or square valve. It has an orifice 2 in which a membrane support 4 is positioned, which rests against a lip 3. This support is mainly flat, provided with perforated areas which will allow the circulation of an atmosphere between the interior volume V_iand the exterior volume V_eof the valve, and therefore of the envelope 30 of the energy storage device. A porous membrane 5 ( ) can be welded to this support, for example by an ultrasonic technique. The membrane is for example an e-PTFE membrane or an open pore foam. It allows, during normal operating phases, to balance the pressures between the interior of the volume and the ambient environment.

The support 4 may comprise or be extended by a central cylindrical part 6, which extends towards the interior of the envelope and inside which a shaft 10 (or a rod or a bar) of a piston 8, forming a valve, will be able to slide. In the shape shown, the piston or the valve is circular in shape, adapted to that of the valve shown. However, if the latter has another shape, for example the rectangular or square shape as already mentioned above, then the piston or the valve has a corresponding shape. A spring 12 maintains this piston 8 in the normally open position, allowing the circulation of an atmosphere between the interior volume V _i and the exterior volume V _e of the envelope, in one direction or another. Preferably, one or more seals 19 ensure tight movement of the shaft 10 in the central cylindrical part 6.

Volume 15, internal to the valve, is either at the internal pressure if the piston is open or at the external pressure if the piston is in the closed position.

A part 14 forming a stop limits the stroke of the piston under the action of the spring. In the representation of Figures 1 and 2, this part 14 is fixed to the body 1, on the side of the interior volume V _i of the envelope. In other words, the spring can push the piston until it is blocked by the part 14, in a position in which the air or the atmosphere can circulate between the exterior volume V _e and the interior volume V _i of the envelope. In a variant, explained below in connection with Figures 3A and 3B, this part forming a stop can be installed at the end of the shaft 10.

Preferably, the piston 8 is in direct contact with the interior volume V _i and with the exterior volume V _e through the end of the shaft 10. Thus, the difference in pressure which is exerted on the piston is indeed the difference between the pressure inside the envelope and the pressure outside it. Alternatively, it is when the internal pressure exceeds a limit value, which allows spring 12 to be pushed back, that the piston is moved to its closed position.

According to a preferred embodiment, the piston 8 as well as its shaft 10 have a symmetry of revolution around the axis AA'. But, as already explained above, other shapes can be made . The piston moves in translation along this axis AA', in this example under the action of the spring 12 and/or a pressure or a pressure difference between the inside and the outside of the valve or of the envelope 30. If the valve and the piston on the valve have a shape different from the circular shape, the piston or the valve can nevertheless move in translation along an axis AA', preferably substantially perpendicular to the wall 30 in which the valve can be installed.

According to a first mode of operation, the pressure difference between the inside and the outside of the valve or the envelope, or the pressure inside the envelope or the valve, does not exceed a value allowing the spring 12 to be compressed: the piston remains abutting against the part 14 and the atmosphere can then circulate between the inside and the outside of the valve or the envelope, via the membrane, the membrane support and the space provided between piston 8 and body 1 (this space is visible in ). For example, the air circulates with an air flow rate of between 0.5 and 100 l/min/cm² under a pressure difference of a few tens of mbar, for example between 20 mbar and 40 mbar.

According to a second mode of operation, the pressure difference between the inside and the outside of the valve or the envelope exceeds the limit value, for example 50 mbar or 70 mbar, or more generally a limit pressure for example between 40 mbar or 50 mbar and 100 mbar, which allows the spring 12 to be compressed, or the pressure of the interior atmosphere of the envelope or the valve exceeds a value which also allows the spring 12 to be compressed. The piston is then pressed against an interior edge, or a lip, 16 of the body 1, thus stopping the circulation of the atmosphere between the exterior and the interior of the valve or the envelope. Thus, the membrane is protected against internal overpressure in the valve or in the envelope. Such an overpressure situation can occur for example in the case of gas release or thermal runaway (for example due to a rapid increase in temperature and an additional volume of combustion gas causing the overpressure). Overpressurized gases, for example from cell combustion, may possibly escape through other orifices or dedicated overpressure valves.

Figures 3A and 3B represent a variant of a valve according to the invention. In these figures, numerical references identical to those of Figures 1 and 2 designate identical or corresponding elements. The difference compared to the previous figures lies in the part 24 which forms a stop to limit the stroke of the piston: this part is here located at the end of the shaft 10 and comes to apply against the membrane when the external pressure is greater to the pressure inside the envelope ( ) ; the air or atmosphere can then circulate between the exterior and interior of the envelope. When the pressure inside the envelope, or the pressure difference between this interior pressure and the exterior pressure, is such that the piston compresses the spring 12, the piston 8 comes to bear against the wall of the body 1, closing thus any possibility of exchange of air or atmosphere between the exterior volume V _e and the interior volume V _i of the envelope ( ).

Figures 4A and 4B represent variants of a valve according to the invention. The valve is provided with a member 92 which, in cooperation with an actuator 90, for example an electric motor, allows, via a transmission member 91, to drive the piston 8 in one direction or in the 'other along axis AA'. Thus, the piston can be driven into its closed position or, on the contrary, into its open position. The member 92 is mechanically linked to the valve; for example, it penetrates the shaft or the rod 10. This member comprises for example a rod or a bar, part of which is furnished with notches or teeth, thus forming a rack, which can be driven in movement by the member 91, which includes for example a toothed wheel. The actuator 90 can control the member 91 under the action of information relating on the one hand to the pressure Pe, and/or the temperature Te, external to the valve (or external to the envelope 30 which is provided of this valve), and information relating to the pressure Pi, and/or the temperature Ti, internal to the valve (or internal to the envelope 30 which is equipped with this valve). For example, if the means 90, 91 for driving the member 92 are located outside the valve (case of the ), the actuator 90 receives information relating to the internal pressure, and/or temperature, from a pressure sensor 93 (and/or a temperature sensor 93'), which can be placed inside of the valve or the envelope, the pressure and/or the external temperature being measured directly using a sensor which can for example be included in the actuator 90. If the means 90, 91 for driving the member 92 are located outside the valve (case of the ), the actuator 90 receives information relating to the external pressure and/or temperature from a pressure sensor 95 (and/or a temperature sensor 95'), which can be placed outside the valve of the envelope, the internal pressure and/or temperature being measured directly using a sensor which can for example be included in the actuator 90.

There represents another variant of a valve according to the invention. The actuating member 90 here comprises one or more coils 97 which interact with one end of the shaft or the rod 10 of the piston. This shaft or this rod comprises a part (shaft or rod) 10' which extends beyond the membrane support 14 and the membrane and which is at least partly magnetized. Thus, depending on the activation of the coil(s) 97 by an electric current, the magnetic field produced by the coil(s) will interact with the end 10' of the axis 10 to move the latter according to the 'axis AA', in one direction or another in order to open or close the breathing valve. As described above, the actuator 90 can receive information relating to the internal pressure and/or temperature from a pressure sensor 93 (and/or a temperature sensor), which can be arranged at the interior of the valve or the envelope, the external pressure and/or temperature being measured directly using a sensor which can for example be included in the actuator 90.

Alternatively, represented in , the same type of drive, by magnetic means, can be implemented on the interior side of the valve, possibly with the pressure and/or temperature sensor(s) arranged correspondingly, for example in the manner explained above in connection with the . In this variant, the actuator comprises at least one or more coil(s) 97 (forming a stator) and at least one magnetized part (fixed to the valve, for example on the part 10' of the piston axis) which allow the closing or opening and even a certain proportional opening of the system.

In these various embodiments with actuator:

- the actuator 90 may comprise, or be connected to, a circuit, for example an electric or electronic circuit, comprising for example at least one comparator, which will compare the two pieces of information relating to pressures, and/or temperatures, internal Pi and/or Ti and external Pe and/or Ti, or information based on, or calculated from, one and/or the other of these parameters, for example the temporal evolution of one and/or the other of these parameters, and, consequently, trigger, or not, the actuation of the member 92 (Figures 4A, 4B) or the magnetic means 97 (Figures 4C, 4D); alternatively, the actuator or circuit can be provided or programmed to trigger, or not, the actuation of the member 92, 10' as a function of a measurement of a pressure/temperature inside the valve or the envelope it contains. In all cases, this circuit can be a circuit programmed and/or adapted to this operation or function;

- and/or the actuator 90 can allow an intermediate opening between the completely closed position of the valve and its completely open position;

- and/or the valve can be controlled using an electrical signal sent to the actuator, a signal which can for example come from a controller or an external circuit or located in the valve, which can receive from one or several sensor(s) internal and/or external pressure and/or temperature information and/or voltage information provided by, or at the terminals of, an energy storage device, and/or other information causing the closing or opening of the valve;

- and/or the valve no longer needs to be fitted with the spring 12 nor with the stop or stop piece 14, 24, the movement of the valve being controlled by the means 90; for example, spring 12 is represented in or 4D, but could be deleted.

In these embodiments, the valve can therefore include an actuator 90 configured to move the valve to open or close the exchange of atmosphere via the valve. The actuator can for example be an electric motor, a piezo actuator or of the magnetic or electromagnetic type, for example an electric magnet, acting on the valve. Thus, the actuator can move the valve between the open position and the closed position. The actuator may be configured to force the valve into a closed position and/or force the valve into an open position and/or exert no force on the valve.

There represents an envelope 30 energy storage device in electrochemical form, for example comprising a plurality of battery packs 110. This envelope 30 is provided with a valve 100 according to the invention and a valve or a valve discharge or evacuation 17 in the event of overpressure and/or internal heating: gases under overpressure and/or overheating in the envelope escape through this valve 17, while the membrane of the valve 100 is protected as explained above.

A valve according to the invention can be applied to a modular energy storage system as illustrated for example in or in .

In each of these figures is shown an envelope 30 of a battery which comprises a plurality of cells 31-36, each cell being arranged in a module or section, separated from each neighboring module or section by a wall, each of the walls separating 2 neighboring modules can be provided with a valve 100 according to the present invention; an end cell may also include such a valve 100. One or more of these valves, for example all the valves 100, may be provided with an actuator 90, for example according to one of the examples described above in connection with Figures 4A-4D. One or more module(s), for example each module, may also be provided with at least one valve or discharge or evacuation valve 17, as already presented above, this is that is to say allowing an escape of the gas or the atmosphere contained in the corresponding module when, for example, a temperature and/or a pressure internal to the module and/or, more generally, a thermodynamic parameter of the atmosphere interior to the module, possibly compared to a thermodynamic parameter of the atmosphere interior to one of the neighboring modules, exceeds a certain threshold value.

In the example of the , the valve 100 which equips the wall which separates the cells 32 and 33 will be sensitive, for example, to the pressure difference between the two compartments which house these two cells. Thus, if the pressure P2 in the cell 32 becomes much higher than the pressure P1 of the cell 33, then the valve 100 will close, in the manner which has been explained above. The same goes for each breathing valve which equips a wall which separates 2 neighboring cells. In other words, each valve 100 reacts to the pressure difference with one of the neighboring modules, except the valve 100 which is fitted to the rightmost wall on the , which reacts to the pressure difference between the module of cell 36 and the external atmosphere.

In the variant of the , each module or section is connected to the exterior atmosphere by at least one connection channel 91, which can be connected to a conduit sheath 95, which opens for example outside the overall envelope 30 of the system, for example still outside a vehicle. Thus, each of the valves 100 will react to the difference in pressure and/or temperature, and/or, more generally, a thermodynamic parameter or its evolution, between the exterior atmosphere and the atmosphere inside the corresponding module.

The architectures explained above in connection with Figures 6A and 6B can be modulated as desired, by adding or removing modules, thus making it possible to design a modular battery, each module being able to be provided with a breathing valve according to the invention and possibly an exhaust valve 17.A valve or an energy storage device according to the invention can be used advantageously in the context of balancing, for example the pressure and/or the temperature of a battery compartment used in the field of transportation, for example in an automobile or truck or an airplane, powered by a thermal engine or an electric motor or a hybrid motor. In this case, the atmosphere outside the valve 100 can be a passenger compartment of the vehicle (as illustrated in ), for example occupied by passengers and/or goods, while the evacuation valve 17 makes it possible to evacuate overpressurized and/or overheated gases into a zone not occupied by passengers and/or goods. Thus, no overpressurized and/or overheated gas will be able to escape towards the passenger compartment in which the passengers and/or goods are located.

The vehicles represented in Figures 7A – 7D, each equipped with an energy storage device 30 according to the present invention, can be:

- of the type for transporting people and/or goods;

- and/or autonomous type;

- and/or type of motor vehicle 200 ( ) and/or construction vehicles, for example of the excavator or backhoe type, or of the aircraft type (for example: airplane 210, ) or of space type, for example a space station or a satellite; or, alternatively, of the type used in the maritime sector, for example a boat 220 ( ) or a ship or boat or submarine, or of the type used in the railway sector, for example a locomotive 230 ( ) or a wagon, or more generally of the type used as an air or land or maritime locomotion vehicle.

In the case of overpressure and/or overheating, a force is applied to piston 8 which closes the breathing valve, which prevents bursting or damage to the membrane; this helps protect this breathing valve throughout the life of the battery or energy storage element. In the case of thermal runaway, the breathing valve, under the effect of the internal pressure and/or temperature or the pressure and/or temperature difference between the internal atmosphere and the external atmosphere, will close and remain in the closed position as long as the applied pressure and/or temperature difference is greater than a limit value, for example greater than 50 mbar.

The invention relates in particular to an application to batteries, in particular lithium-ion batteries, which consist of a sealed envelope comprising a set of unit cells and most of the time electronic and power components for their interconnection and control.

The invention has been described above in the context of actuation of the closing and opening valve as a function of pressure and/or temperature or pressure and/or temperature differences. But a valve according to the invention can also be activated as a function of another type of signal or as a function of an external action, for example from an operator, who wishes to control or test, for example as part of a maintenance operation, the operation of a valve according to the invention. For example, the valve of a valve according to the invention can be provided with activation means such as means 90 adapted and/or programmed to close or open the valve as a function of another type of signal, for example a variation in pressure and/or temperature, for example during a predetermined time interval (such a variation being compared to a limit value, or threshold, of variation in pressure and/or temperature), or an external action triggered by an operator.

Alternatively, a valve according to the invention can be activated to close in the case of detection of a failure: such a failure can be measured for example in the case of an excessively high temperature of a unit cell or of a set of electrochemical storage cells, for example a module or an enclosure as illustrated in Figures 5 or 6A, 6B.

The failure may for example be an abnormal temperature, for example 70°C or more and/or an overvoltage and/or, on the contrary, a sudden drop in cell voltage or the energy storage device. One or more corresponding sensor(s), for example voltage detection, may equip the system, for example in addition to the temperature and/or pressure detection sensor(s) already described ( s) above, in particular in connection with Figures 4A-4D. The corresponding information can be transmitted to a control unit, for example the means 90 as already described above and/or computer means, for example a microcomputer or a microprocessor, to which can be connected, for example, the means 90.

When a failure is detected, it is possible to confine certain sections or certain modules in relation to others (case, for example, of the systems of Figures 6A and 6B) by closing the corresponding valve(s) ( s), thus protecting a certain area of the system in relation to another.

Claims (28)

Breathing valve (100) for an energy storage device in electrochemical form, this device comprising an envelope (30), this valve itself comprising:
- a valve body (1);
- a membrane support (4) for supporting a membrane allowing circulation between an exterior atmosphere (V _e ) and the interior atmosphere (V _i ) at the valve;
- means (8, 10) forming a valve for opening and closing the valve;
- activation means (12, 14, 24, 90, 91, 92) for activating the means (8, 10) forming a valve between a first position, called opening, of the valve and a second position, called opening closing the valve, these activation means authorizing, in said first position, circulation between the interior atmosphere and the atmosphere exterior to the valve, and closing, in said second position, said circulation. Valve according to claim 1, the activation means allowing, in said first position, circulation between the interior atmosphere and the atmosphere exterior to the valve, when at least one thermodynamic parameter of the interior atmosphere or the difference 'a thermodynamic parameter between the interior atmosphere and the exterior atmosphere, or a variation of this thermodynamic parameter, is less than a limit value and closing, in said second position, said circulation, for example when said thermodynamic parameter, or its difference between the indoor atmosphere and the outdoor atmosphere, or its variation, is greater than the limit value. Valve according to claim 2, in which said at least one thermodynamic parameter, or its difference between the interior atmosphere and the exterior atmosphere, or its variation, comprises at least the pressure and/or the temperature, or the difference in pressure and/or the temperature between the interior atmosphere and the exterior atmosphere and/or a variation in pressure and/or temperature of the interior atmosphere and/or the exterior atmosphere. Valve according to one of claims 1 to 3, the means (8, 10) forming a valve bearing against an interior part (16) of the body of the valve when at least one thermodynamic parameter, for example pressure and/or the temperature of the interior atmosphere and/or the exterior atmosphere is greater than a limit value or when the difference in temperature and/or pressure between the interior atmosphere and the exterior atmosphere is greater than a limit value. Valve according to one of claims 1 to 4, the means (8, 10) forming a valve comprising a piston (8). Valve according to one of claims 1 to 5, the means (8, 10) forming a valve, comprising a part (8) in contact with the interior atmosphere of the valve and a part (10) in contact with the exterior atmosphere of the valve. Valve according to one of claims 1 to 6, the means (8, 10) forming a valve moving along a stroke which is limited, in the first position, by a stop (14, 24). Valve according to claim 7, the stop (14) being located on the interior side of the valve. Valve according to claim 7, the stop (24) being located on the exterior side of the valve. Valve according to one of claims 1 to 9, comprising means (12) for constraining the means (8, 10) forming a valve in the open position, for example up to a limit value of a thermodynamic parameter of the atmosphere. Valve according to the preceding claim, the activation means comprising a spring (12) bearing on the one hand against the means (8, 10) forming a valve and on the other against the membrane support (4). Valve according to one of claims 1 to 11, the means (8, 10) forming a valve comprising an axis (10) which penetrates into a central extension of the membrane support. Valve according to one of claims 1 to 12, the activation means comprising an actuator (90) and means (91, 92, 97) for moving the means forming a valve. Valve according to claim 13, said movement means (91, 92) comprising mechanical means for driving the means forming a valve. Valve according to claim 13, said movement means (97) comprising magnetic means (97) for driving the means forming a valve. Valve according to one of Claims 13 to 15, further comprising at least one pressure and/or temperature sensor (93.95, 93', 95') and/or voltage for measuring at least one pressure and/or temperature inside the valve and/or outside the valve and/or the voltage of an energy storage device, and means for providing the actuator (90) with information relating to said pressure and/or temperature and/or tension. Energy storage enclosure in electrochemical form, for example battery type, comprising an envelope (30) containing one or more energy storage elements (31-36, 110), this envelope being provided with at least one breathing valve (100) according to one of claims 1 to 16. Storage enclosure according to claim 17, further comprising at least one evacuation valve (17) which allows exhaust from the interior atmosphere to the exterior atmosphere of the enclosure when a thermodynamic parameter is greater than a limit value , the valve means of the breathing valve then closing the circulation of atmosphere therethrough. Storage enclosure according to one of claims 17 or 18, comprising a plurality of energy storage elements (31-36), each element being arranged in a module separated from each of the neighboring modules by a wall, at least one said walls being provided with a breathing valve (100) according to one of claims 1 to 16. Storage enclosure according to claim 19, each module being provided with an evacuation valve (17) which allows exhaust from the interior atmosphere of each module towards the exterior atmosphere of the enclosure when a thermodynamic parameter is greater than a limit value. Storage enclosure according to one of claims 19 or 20, each module being connected to the external atmosphere by at least one connection channel (91). Valve according to one of claims 1 to 16, or storage enclosure according to one of claims 17 to 21, further comprising means for detecting a failure in the energy storage device or in the storage enclosure. Vehicle, comprising a passenger compartment and/or a storage area, an engine, and at least one energy storage enclosure according to one of claims 17 to 22, each breathing valve (100) being in fluid communication with the passenger compartment and/or the storage area, at least one evacuation valve (17) allowing gas to escape outside the passenger compartment and/or the storage area. Vehicle according to claim 23, this vehicle being:
- of the type for transporting people and/or goods;
- and/or autonomous type;
- and/or type of motor vehicle and/or construction vehicles, for example of the excavator or backhoe type, or of the aircraft type or of the space type, or of the type used in the maritime sector, for example boat or vessel or craft or submarine, or of the type used in the railway sector, for example locomotive or wagon. Method for controlling a valve (100) of an enclosure of an energy storage device in electrochemical form, comprising an envelope (30), this valve itself comprising:
- a valve body (1);
- a membrane support (4) for supporting a membrane allowing circulation between an exterior atmosphere (V _e ) and the interior atmosphere (V _i ) at the valve,
- means (8, 10) forming a valve for opening and closing the valve;
process in which
- activation means (12, 14, 24, 90, 91, 92) activate the means (8, 10) forming a valve between a first position, called opening, of the valve and a second position, called closing of the valve, these activation means authorizing, in said first position, circulation between the interior atmosphere and the atmosphere exterior to the valve, and closing, in said second position, said circulation. Method for controlling a valve (100) according to one of claims 1 to 16, or a valve of an energy storage enclosure according to one of claims 17 to 22, or a valve 'a vehicle according to one of claims 23 or 24, this method comprising the activation of the means (8, 10) forming a valve between a first position, called opening, of the valve and a second position, called closing of the valve. the valve, these activation means authorizing, in said first position, circulation between the interior atmosphere and the atmosphere exterior to the valve and closing, in said second position, said circulation. Method according to claim 25 or 26, said activation means:
- authorizing, in said first position, circulation between the interior atmosphere and the atmosphere exterior to the valve, when the pressure and/or temperature of the interior atmosphere or the difference in pressure and/or temperature between the interior atmosphere and the exterior atmosphere, is less than a limit value of pressure and/or temperature or pressure and/or temperature difference;
- and closing, in said second position, when said pressure and/or said temperature is greater than the pressure and/or temperature limit value or when the pressure and/or temperature difference between the interior atmosphere and the atmosphere outside temperature is greater than the pressure/temperature difference limit value. Method according to one of claims 25 to 27, said activation means being activated by an operator.