FR3140662A1 - BREATHING VALVE SYSTEM WITH OVERPRESSURE PROTECTION - Google Patents

Abstract

The invention relates to a breathing valve (100) for a device for storing energy 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 OVERPRESSURE 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 electrochemical type solutions.

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

In general, electrochemical storage means, such as fuel cells, must be waterproof and dustproof, for example, but must be able to exchange a certain amount of air with the surrounding environment, in both directions, in order to balance the pressure. This reduces the constraints on the casing containing these storage means, facilitates transport and ensures optimal use regardless of 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 a bursting of the casing, for example of a battery pack.

The problem therefore arises of finding a system or device making it possible to achieve breathing, or balancing, for example of the pressure and/or temperature and/or another thermodynamic parameter, between the internal atmosphere of an envelope of an electrochemical type storage unit and the external atmosphere of this envelope, this system or device benefiting from protection in the event of internal overpressures in 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 whole.

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

- a valve body;

- a membrane support for supporting a membrane allowing circulation between an external atmosphere (V _e ) and the internal atmosphere (V _i ) at the valve or casing;

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

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

- to authorize, in said first position, the circulation between the atmosphere inside and the atmosphere outside the valve, for example when a pressure and/or a temperature, called reference, for example equal to the pressure and/or the 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 interior atmosphere and/or the exterior atmosphere, for example during 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 higher than said pressure and/or temperature limit value.

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

- a valve body;

- a membrane support for supporting a membrane allowing circulation between an external atmosphere (V _e ) and the internal atmosphere (V _i ) at the valve or casing;

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

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

* and/or to close, in a second position, called the closed position, said circulation, when the pressure and/or temperature, called the reference pressure, is higher 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 event of overpressure and/or heating of the atmosphere inside the valve or a casing provided with this valve; the invention also relates to a method for controlling or operating such a valve.

The examples of opening or closing of the valve according to the invention or of a method according to the invention, under the action of pressure and/or temperature and/or, more generally, of a thermodynamic parameter, or of differences in pressure and/or temperature and/or of the thermodynamic parameter or of a variation in pressure and/or temperature and/or of the thermodynamic parameter, mentioned above and in the remainder of this description are 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 a detection of a variation in temperature and/or a variation in pressure or under an external action, for example of 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 of a voltage which is too low or too high, i.e. lower than a ^1st limit value or higher than a ^2nd limit value, this voltage being measured at the terminals of an energy storage device, or being the voltage supplied by such an energy storage device, equipped with the valve.

More generally, in a valve according to the invention or in a method according to the invention, the activation means or the valve-forming means may:

- authorizing, in said first position, the circulation between the interior atmosphere and the atmosphere outside the valve, when at least one thermodynamic parameter of the interior atmosphere or the difference of a thermodynamic parameter between the interior atmosphere and the exterior atmosphere, or its variation, for example during 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 than said limit value.

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

In a valve or in a method according to the invention, the flap-forming means can, in the closed position, come to bear against an internal 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/or pressure is greater than a limit value.

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

- the valve means comprise a piston.

- and/or the valve-forming means may comprise a part in contact with the atmosphere inside the valve and a part in contact with the atmosphere outside the valve;

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

This stop can be located on the inside of the valve, or on the outside of the valve.

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

According to a particular embodiment, the valve means of 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 valve means to be truly sensitive to a difference, for example of pressure, between the internal atmosphere and the external 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 valve-forming means.

For example, a valve, or a valve controlled or commanded 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 voltage sensor, 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 the latter, or a variation of this pressure and/or of this temperature, inside the valve and/or outside the valve and/or of this voltage; optionally, means, for example one or more connections between said at least one such sensor and an actuator as mentioned above to provide the latter with at least one pressure and/or temperature information, external to the valve and/or at least one pressure and/or temperature information, internal to the valve and/or at least one voltage information, for example from the device or an energy storage device, measured at the terminals thereof or provided by the latter. The actuator can therefore be controlled by signals coming from one or more pressure and/or temperature and/or voltage sensors, for example external and/or internal to the valve or to the casing which is provided 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 outside 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 valve means may comprise mechanical means for driving the valve means. For example, the actuator means actuate a rod or bar mechanically connected to the valve means, for example to the piston or to the rod which extends it.

Alternatively, the means for moving the valve means comprise magnetic or electromagnetic means for driving the valve means. The valve means may be extended by a shaft or rod, at least one part of which is magnetized; this part may interact with said magnetic or electromagnetic means. The actuator means then comprise at least one magnetized 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 a lithium-ion battery, comprising an envelope containing one or more energy storage elements, for example one or more 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 the interior atmosphere to escape to the exterior atmosphere of the enclosure, in particular when the valve according to the invention is in its closed position, for example when the reference pressure and/or temperature is higher than the limit pressure and/or temperature, the valve-forming means of the breathing valve then closing the circulation of atmosphere through it.

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 breathing valve 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 may be provided with an exhaust valve which allows the interior atmosphere of each module to escape to the exterior atmosphere of the enclosure when a thermodynamic parameter, for example 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 outside atmosphere by at least one connecting 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 outside atmosphere of the storage enclosure.

A valve according to the invention, or a valve controlled or commanded 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 further comprise, means for detecting a failure in one or in 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 the energy storage enclosure or of one or more 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 comprise 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 area; if, in addition, the enclosure is provided with an evacuation valve, then the latter allows the gas to escape outside the passenger compartment and/or the storage area.

Such a vehicle is, for example, a car or a truck or an airplane or construction equipment, for example an excavator or a shovel, the engine being able to be a thermal engine or an electric engine 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 digger type, or of the aircraft or space type, or of the type used in the maritime field, for example boat or ship or vessel or submarine, or of the type used in the railway field, for example locomotive or wagon, more generally of the type used as an air, land or sea locomotion machine.

The invention also relates to a method of operating or controlling the 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 of an enclosure of an electrochemical energy storage device, comprising an envelope, this valve, for example as set out above according to the present invention, itself comprising:

- a valve body;

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

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

process in which

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

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

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

- authorizing, in said first position, circulation between the atmosphere inside and the atmosphere outside the valve,

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

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

- allow, in a first position, circulation between the internal atmosphere and the atmosphere inside the valve, for example when a pressure and/or temperature, called reference, equal to the pressure and/or temperature of the internal atmosphere or to the difference in pressure and/or temperature between the internal atmosphere and the external atmosphere, is lower 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 higher than the limit pressure and/or temperature value.

Alternatively, a method according to the invention may comprise the activation of said activation means by an operator, for example as part of a maintenance or valve testing operation.

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 monitoring 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 provided 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 the other of the parameters already mentioned above or further on 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 the problems of balancing, for example the pressure and/or the 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 the temperature of one or more storage elements, for example a battery pack, a valve according to the invention makes it possible to block the exchange of gases. Overpressured and/or overheated gases may possibly be evacuated by 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 at the terminals of an energy storage device according to the invention or supplied by such a device, or of an 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 protective flap of the valve.

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

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

DETAILED DESCRIPTION OF SPECIFIC 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 casing 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 comes to rest against a lip 3. This support is mainly flat, provided with openwork zones which will allow the circulation of an atmosphere between the interior volume V_iand the external 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 inside of the casing 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 form shown, the piston or the valve is of circular 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 internal volume V _i and the external volume V _e of the casing, in one direction or another. Preferably, one or more seals 19 make it possible to ensure a sealed 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 FIGS. 1 and 2, this part 14 is fixed to the body 1, on the side of the internal volume V _i of the envelope. In other words, the spring can push the piston back until it is blocked by the part 14, in a position in which the air or atmosphere can circulate between the external volume V _e and the internal volume V _i of the envelope. In a variant, explained below in connection with FIGS. 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 internal volume V _i and with the external volume V _e via the end of the shaft 10. Thus, the pressure difference exerted on the piston is indeed the difference between the pressure inside the casing and the pressure outside the casing. Alternatively, it is when the internal pressure exceeds a limit value, which allows the spring 12 to be pushed back, that the piston is moved into its closed position.

According to a preferred embodiment, the piston 8 and its shaft 10 have a symmetry of revolution around the axis AA'. However, as already explained above, other shapes can be produced . 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 the casing 30. If the valve and the piston at the flap have a shape other than circular, the piston or the flap 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 casing, or the pressure inside the casing or the valve, does not exceed a value allowing the spring 12 to be compressed: the piston remains in abutment against the part 14 and the atmosphere can then circulate between the inside and the outside of the valve or the casing, via the membrane, the membrane support and the space provided between the piston 8 and the body 1 (this space is visible in ). For example, air flows 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 casing 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 makes it possible to compress the spring 12, or the pressure of the atmosphere inside the casing or the valve exceeds a value which also makes it possible to compress the spring 12. The piston is then pressed against an inner edge, or a lip, 16 of the body 1, thus stopping the circulation of the atmosphere between the outside and the inside of the valve or the casing. Thus, the membrane is protected against excess pressure inside the valve or the casing. Such an overpressure situation may occur for example in the case of gas release or thermal runaway (e.g. due to a rapid temperature increase and an additional volume of combustion gases leading to overpressure). Overpressure gases, for example from cell combustion, may possibly escape through other dedicated orifices or pressure relief valves.

Figures 3A and 3B show 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 be applied against the membrane when the external pressure is greater than the pressure inside the casing ( ) ; air or atmosphere can then circulate between the outside and the inside of the envelope. When the pressure inside the envelope, or the pressure difference between this internal pressure and the external pressure, is such that the piston compresses the spring 12, the piston 8 comes to bear against the wall of the body 1, thus closing any possibility of exchange of air or atmosphere between the external volume V _e and the internal volume V _i of the envelope ( ).

Figures 4A and 4B show 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, by means of a transmission member 91, to drive the piston 8 in one direction or the other along the 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 into the shaft or the rod 10. This member comprises for example a rod or a bar, a part of which is provided with notches or teeth, thus forming a rack, which can be driven into movement by the member 91, which comprises 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 casing 30 which is provided with this valve), and of information relating to the pressure Pi, and/or the temperature Ti, internal to the valve (or internal to the casing 30 which is provided 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 arranged inside the valve or the casing, the external pressure and/or 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 arranged 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 rod 10 of the piston. This shaft or 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 latter will interact with the end 10' of the axis 10 to move the latter along 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 inside the valve or the casing, the external pressure and/or temperature being measured directly using a sensor which can for example be included in the actuator 90.

Alternatively, shown in , the same type of drive, by magnetic means, can be implemented on the inner side of the valve, with possibly 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 electrical or electronic circuit, comprising for example at least one comparator, which will compare the two pieces of information relating to the 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 (FIGS. 4A, 4B) or the magnetic means 97 (FIGS. 4C, 4D); as a variant, the actuator or the circuit may be provided or programmed to trigger, or not, the actuation of the member 92, 10' according to a measurement of a pressure/temperature inside the valve or the casing that it comprises. In any case, this circuit can be a programmed circuit and/or adapted to this operation or function;

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

- and/or the valve can be controlled by 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 more sensors information on pressure and/or internal and/or external temperature and/or voltage information provided by, or at the terminals of, an energy storage device, and/or other information causing the valve to close or open;

- and/or the valve no longer needs to be fitted with the spring 12 or the stop or stop piece 14, 24, the movement of the flap being controlled by the means 90; for example, the spring 12 is shown in or 4D, but could be deleted.

In these embodiments, the valve may therefore comprise an actuator 90 configured to move the valve to open or close the exchange of atmosphere via the valve. The actuator may for example be an electric motor, a piezo actuator or a magnetic or electromagnetic type actuator, 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 blocks 110. This envelope 30 is provided with a valve 100 according to the invention and a flap or a discharge or evacuation valve 17 in the event of overpressure and/or internal heating: the 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 being able to be provided with a valve 100 according to the present invention; an end cell can also comprise such a valve 100. One or more of these valves, for example all the valves 100, can be provided with an actuator 90, for example according to one of the examples described above in connection with FIGS. 4A-4D. One or more modules, for example each module, may also be provided with at least one discharge or evacuation valve or flap 17, as already presented above, that is to say allowing an escape of the gas or 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 inside the module, possibly compared to a thermodynamic parameter of the atmosphere inside 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 was explained above. The same applies to 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 equips the rightmost wall on the , which reacts to the pressure difference between the cell module 36 and the outside atmosphere.

In the variant of the , each module or section is connected to the outside atmosphere by at least one connecting 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, of a thermodynamic parameter or its evolution, between the outside atmosphere and the atmosphere inside the corresponding module.

The architectures explained above in connection with FIGS. 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 temperature of a battery compartment used in the field of transport, for example in an automobile or a truck or an airplane, powered by a heat engine or an electric motor or a hybrid engine. 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 discharge valve 17 allows overpressure and/or overheated gases to be discharged into an area not occupied by the passengers and/or goods. Thus, no overpressure and/or overheated gases can escape towards the passenger compartment in which the passengers and/or goods are located.

The vehicles shown 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 excavators or diggers, or aircraft (for example: 210 aircraft, ) or of a space type, for example a space station or a satellite; or, alternatively, of the type used in the maritime field, for example a boat 220 ( ) or a ship or boat or submarine, or of the type used in the railway field, for example a locomotive 230 ( ) or a wagon, or more generally of the type used as an aerial, land or sea locomotion device.

In the event of overpressure and/or overheating, a force is applied to the piston 8 which closes the breathing valve, which prevents the membrane from bursting or being damaged; this protects this breathing valve throughout the life of the battery or energy storage element. In the event 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 an actuation of the closing and opening valve as a function of pressure and/or temperature or pressure and/or temperature differences. However, 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 of 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 the 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 event of a failure being detected: such a failure can be measured for example in the event of an excessively high temperature of a unit cell or a set of electrochemical storage cells, for example a module or an enclosure as illustrated in figures 5 or 6A, 6B.

The failure may be, for example, 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 of the energy storage device. One or more corresponding sensors, for example for voltage detection, may equip the system, for example in addition to the temperature and/or pressure detection sensor(s) already described above, in particular in connection with FIGS. 4A-4D. The corresponding information may 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, for example, the means 90 may be connected.

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

Claims (28)

Breathing valve (100) for an electrochemical energy storage device, this device comprising a casing (30), this valve itself comprising:
- a valve body (1);
- a membrane support (4) for supporting a membrane allowing circulation between an external atmosphere (V _e ) and the internal atmosphere (V _i ) at the valve;
- means (8, 10) forming a flap for opening and closing the valve;
- activation means (12, 14, 24, 90, 91, 92) for activating the valve-forming means (8, 10) between a first position, called the opening position, of the valve and a second position, called the closing position of the valve, these activation means authorizing, in said first position, the circulation between the atmosphere inside and the atmosphere outside the valve, and closing, in said second position, said circulation. Valve according to claim 1, the activation means allowing, in said first position, the circulation between the atmosphere inside and the atmosphere outside the valve, when at least one thermodynamic parameter of the interior atmosphere or the difference of 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 interior atmosphere and the exterior atmosphere, or its variation, is greater than the limit value. Valve according to claim 2, wherein said at least one thermodynamic parameter, or its difference between the internal atmosphere and the external atmosphere, or its variation, comprises at least the pressure and/or the temperature, or the difference in pressure and/or temperature between the internal atmosphere and the external atmosphere and/or a variation in pressure and/or temperature of the internal atmosphere and/or the external atmosphere. Valve according to one of claims 1 to 3, the means (8, 10) forming a flap bearing against an internal part (16) of the body of the valve when at least one thermodynamic parameter, for example the pressure and/or the temperature of the internal atmosphere and/or of the external atmosphere, is greater than a limit value or when the difference in temperature and/or pressure between the internal atmosphere and the external 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 flap 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 inner side of the valve. Valve according to claim 7, the stop (24) being located on the outside of the valve. Valve according to one of claims 1 to 9, comprising means (12) for forcing 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 flap 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 valve-forming means. Valve according to claim 13, said displacement means (91, 92) comprising mechanical means for driving the valve-forming means. Valve according to claim 13, said displacement means (97) comprising magnetic means (97) for driving the valve-forming means. 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 sensor 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 voltage. Energy storage enclosure in electrochemical form, for example of the 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 an escape of the interior atmosphere towards the exterior atmosphere of the enclosure when a thermodynamic parameter is greater than a limit value, the valve-forming means of the breathing valve then closing the circulation of atmosphere through it. 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 of 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 an escape of the atmosphere inside each module towards the atmosphere outside 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 connecting 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 the 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 excavator or digger type, or aircraft type or space type, or of the type used in the maritime field, for example boat or ship or vessel or submarine, or of the type used in the railway field, for example locomotive or wagon. Method for controlling a valve (100) of an enclosure of an electrochemical energy storage 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 external atmosphere (V _e ) and the internal atmosphere (V _i ) at the valve,
- means (8, 10) forming a flap for opening and closing the valve;
process in which
- activation means (12, 14, 24, 90, 91, 92) activate the valve-forming means (8, 10) between a first position, called the opening position, of the valve and a second position, called the closing position of the valve, these activation means authorizing, in said first position, the circulation between the atmosphere inside and the atmosphere outside 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 of 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 the opening position, of the valve and a second position, called the closing position of the valve, these activation means authorizing, in said first position, the circulation between the atmosphere inside and the atmosphere outside 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, the circulation between the interior atmosphere and the atmosphere outside the valve, when the pressure and/or temperature of the interior atmosphere or the pressure and/or temperature difference between the interior atmosphere and the exterior atmosphere is lower 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 higher than the pressure and/or temperature limit value or when the pressure and/or temperature difference between the internal atmosphere and the external atmosphere is higher than the pressure/temperature difference limit value. Method according to one of claims 25 to 27, said activation means being activated by an operator.