EP2649663A1

EP2649663A1 - Device for generating electricity using a fuel cell

Info

Publication number: EP2649663A1
Application number: EP11802308.4A
Authority: EP
Inventors: David Olsommer
Original assignee: Michelin Recherche et Technique SA Switzerland; Compagnie Generale des Etablissements Michelin SCA; Michelin Recherche et Technique SA France
Current assignee: Michelin Recherche et Technique SA Switzerland; Compagnie Generale des Etablissements Michelin SCA; Michelin Recherche et Technique SA France
Priority date: 2010-12-06
Filing date: 2011-12-05
Publication date: 2013-10-16
Also published as: WO2012076445A1; CN103250292A; FR2968462B1; JP2014506375A; CN103250292B; FR2968462A1; JP6022474B2; US20130302706A1

Abstract

The invention relates to a device for generating electricity using a fuel cell, including a means (1) for generating fuel and comburent gases, and at least one unit (2, 3, 4, 5, 6, 7, 9, 10) for packaging either the fuel or comburent gas. The packaging unit includes at least one means (3) for drying before the pressurized storage of the gas, at least one means (5) for the pressurized storage of the gas, and at least one means for humidifying the gas after removing same from storage. According to the invention, the drying means (3) is configured such that, in a fuel-cell operating mode, said means operates at a temperature at least equal to 60°C, and at least partially provides the humidification of the gas passing therethrough in the fuel-cell operating mode, by means of at least partially restoring the water extracted from the gas passing therethrough in a gas-production/storage operating mode.

Description

DEVICE FOR GENERATING ELECTRICITY BY BATTERY A

COMBUSTIBLE

The invention relates to a device for producing electricity by fuel cell.

The invention relates more particularly to a fuel cell type of electricity generation device "closed loop" or "integrated system", that is to say in which the means for producing gas supplying the battery fuel, the means of packaging and storage of these gases, as well as the fuel cell itself are combined in the same device. US2004126641 and WO03041204 disclose such integrated systems.

The invention is more particularly described, but not limited to, for applications in the automotive field, in which this technology is the subject of important research and looks promising. The invention can also be used advantageously in the naval or aeronautical fields.

These applications may be mobile, in the case where the fuel cell electricity generation device is embedded in the vehicle, or stationary, in the case where the fuel cell electricity generation device is a means outside the vehicle and for supplying energy to a vehicle in a station. The application can also be used in the stationary field for energy storage.

In the case of a mobile application, the fuel cell electricity generation device is generally associated with another source of energy which may be of an electrical nature, for example and in a nonlimiting manner, originating from photovoltaic panels. Such a fuel cell electricity generating device thus makes it possible to produce and store energy, and to supply electrical energy on demand when the main source of energy is not available or insufficient. It is known that fuel cells allow the direct production of electrical energy by an electrochemical oxidation-reduction reaction from a fuel gas, such as hydrogen gas, and an oxidizing gas, such as gaseous oxygen or air, without going through a conversion to mechanical energy. The fuel cells are called hydrogen-oxygen type when the gas respectively fuel and oxidant are hydrogen gas and oxygen gas, or hydrogen-air type when the gas respectively fuel and oxidant are hydrogen gas and the air.

[0008] A fuel cell generally comprises a series association of unitary elements, each unitary element consisting essentially of an anode and a cathode separated by an electrolyte. A typical type of electrolyte used in automotive applications is a solid electrolyte consisting essentially of a polymer membrane, allowing the passage of ions from the anode to the cathode. A particular type of these membranes is proposed for example by the company DuPont under the trade name "Nafion". These membranes must have good ionic conductivity because they are traversed by the hydrogen protons and they must be electrically insulating so that the electrons go through the electrical circuit outside the battery. It is known that, not only for membranes of the type indicated above but also for other membranes used as solid electrolyte in fuel cells, the conductivity of the membranes is a function of their water content. This is the reason why the feed gases of the battery must be sufficiently wet. Thus a fuel cell must be supplied with fuel and oxidant gas with a sufficient water content, but not excessive. To this end, the fuel and wet oxidant fueling the fuel cell may result from a multistage process, described below in the case of a hydrogen-oxygen fuel cell.

The first step, in the case of a hydrogen-oxygen fuel cell, consists in producing hydrogen gas and gaseous oxygen, using a means for producing gas by electrolysis of water or electrolyser, the water that can be recovered at the fuel cell outlet, as described in document WO 2010/024594. The gaseous hydrogen and the gaseous oxygen from the electrolyser are then saturated with water vapor. At the end of this first step, the hydrogen and oxygen gases are packaged separately and the steps described below are described for a given gas.

The second step consists in desiccating each gas before storage under pressure, that is to say at least a partial drying or extraction of the water contained in the gas. Desiccation of the gas is necessary because the water condensates are detrimental both to the life of the compressors, possibly used to compress the gas before storage, and to that of the gas storage tanks. Usually, the gas is dried either by cooling and condensing the gas, or by passing the gas through a desiccant means. Drying by cooling and condensing the gas requires an energy input. Drying by passing the gas through a desiccant means usually uses a desiccant means comprising a solid phase desiccant material. In particular, the drying means may be a desiccation column, generally filled with desiccant granules, for example of the silica gel type, as mentioned in the document WO2007050447. Drying by passing the gas through a desiccant column requires maintenance of the desiccant granules. Indeed, desiccant granules, after a number of passages of the gas to be dried, become saturated with water and therefore inoperative in their desiccation function. These desiccant granules are then either renewed periodically, which requires a normal maintenance intervention, or regenerated, that is to say dried automatically, by purging a portion of the gas produced by electrolyser and passing through the desiccation column, resulting in a loss of gas volume produced by electrolyser of about 10%.

The third step is to compress the dried gas from the desiccant means, by means of a compressor and to store the dried compressed gas in a storage tank under pressure. Typically, the storage pressure of the hydrogen gas, after desiccation, is between 200 bars and 350 bars, whereas the storage pressure of the gaseous oxygen, after desiccation, is about 130 bars. An alternative solution for the storage of hydrogen is the storage, in the form of metal hydrides, at low pressure, that is to say at a pressure of between 5 bars and 15 bars. This storage pressure corresponds substantially to the pressure of the hydrogen gas at the outlet of the desiccation means, which makes the use of a compressor superfluous. The metal hydrides, composed, for example, of nickel and lanthanum, and in the form of fine powder, have the particularity of absorbing hydrogen gas under a certain pressure, with a slight release of heat. To then release the hydrogen, a heat input is necessary: for example, by using the thermal losses of the fuel cell. Once released, the hydrogen is again in the form of pure gaseous hydrogen.

The fourth step is to destock the compressed dried gas and relax by means of a pressure reducer, optionally coupled to a safety valve. In the particular case of the destocking of hydrogen, stored in the form of metal hydrides, this step consists in releasing hydrogen, absorbed by the metal hydrides, in gaseous form, as described above.

The fifth step is to humidify the dried gas expanded to supply the fuel cell with wet hydrogen fuel gas and wet oxygen oxidizing gas. A wet gas is indeed necessary for the operation of the fuel cell, in particular to not reduce its life. There are several humidification techniques that can be complex, cumbersome and expensive. Notably, and not exclusively, recirculation on the hydrogen circuit, as described in US2003031906, the Nafion microtube moisture exchanger, the enthalpy wheel, the water mist injection. The sixth and last step is the supply of the battery with wet hydrogen and oxygen gas from their respective humidifying means.

In the case of a hydrogen-air fuel cell, only the hydrogen gas follows the six process steps previously described. With regard to the first step relating to the production of gaseous hydrogen by electrolysis of water, gaseous oxygen, produced simultaneously but not intended for For example, fueling the fuel cell can be released into the atmosphere. As regards the combustion gas, the air, usually from an air compressor, can be humidified, before entering the fuel cell, by the moist air coming out of the fuel cell, via a moisture exchanger. The invention aims to overcome the disadvantages of the desiccation means described above, in particular the periodic maintenance and / or non-optimized regeneration of the desiccant means, and the complexity and cost of the humidifying means.

The object of the invention is to provide a device for producing electricity by fuel cell, ensuring both an automatic maintenance and efficient drying means and the use of simplified humidification means.

This object is achieved by means of a fuel cell power generation device, comprising:

a fuel gas production means and an oxidizing gas production means, the fuel and oxidant gases being intended to feed a fuel cell in which they chemically react with each other to produce electrical energy,

at least one conditioning unit for one of the fuel or oxidant gases, comprising at least one desiccating means, intended to extract at least part of the water contained in the gas passing through it before storage under pressure of the gas, at least two valves respectively upstream and downstream of the desiccant means, at least one means for storage under pressure of the gas and at least one humidification means after destocking and decompression of the gas,

the valves, in a first state, making it possible to configure the electricity generating device in the gas production-storage operating mode, by connecting in series the means for producing the gas, the drying means and the storage means under gas pressure,

the valves, in a second state, for configuring the power generation device in fuel cell operation mode, allowing passing one of the fuel or oxidant gases through the desiccant means for supplying the fuel cell,

and the drying means being configured such that, in the fuel cell operating mode, it operates at a temperature of at least 60 ° C and at least partly ensures the humidification of the gas passing therethrough in battery operation mode fuel, by at least partial return of the water extracted from the gas passing therethrough in the production-gas storage operation mode.

A fuel cell electricity production device comprises, firstly, a fuel gas production means and a combustion gas production means. These means of production are usually combined into a single means for producing gas, in the case of a hydrogen-oxygen cell. This means of producing common gas is conventionally an electrolyzer, producing hydrogen and gaseous oxygen by electrolysis of water. The water subjected to electrolysis is generally stored in a water tank, which may possibly be supplied at least partly with recycle water, from a condenser possibly disposed downstream of the electrolyser and / or from the fuel cell. . In the case of a hydrogen-air fuel cell, the gas production means are distinct: the gaseous hydrogen is usually derived from an electrolyser while the air generally comes from an air compressor. A device for producing electricity by hydrogen-oxygen fuel cell further comprises a packaging unit for each of the hydrogen and oxygen gases. This packaging assembly comprises at least one desiccation means before storage under pressure of the gas, at least one means for storage under pressure of the gas and at least one humidifying means after destocking the gas. In the case of a hydrogen-air fuel cell, only hydrogen gas has a priori a packaging assembly within the meaning of the invention.

As described above, a drying means is a means of drying the gas, that is to say at least partial extraction of the water contained in the gas, before its compression by a compressor and then its compressor. storage in compressed form in a pressurized storage means such as a storage tank storage. Indeed, a compressor and a storage tank, generally comprising metal parts, have a sensitivity to corrosion by water possibly present in the gas in contact, hence the need to dry the gas to ensure the durability of the parts metal compressor and storage tank. As an alternative for hydrogen, the storage can be carried out in the form of hydrides at low pressure, that is to say between 5 bars and 15 bars, without resorting to a compressor. For hydrides, it is also necessary to first dry the gas, to ensure a long life of the storage means.

A gas, resulting from the electrolysis of water and saturated with water vapor, may optionally be partially dried by passage through a condenser intended to remove some of the water from the gas before passing through the medium. desiccation. This condenser may have as a cold source ambient air, or more advantageously for naval application, seawater via a heat exchanger. The pressure storage means of the dry gas is generally a storage tank, sized to withstand the pressure of the gas.

To then feed the fuel cell, the dry gas - hydrogen gas or gaseous oxygen - is removed from its storage tank, decompressed through a pressure regulator before passing through a humidifying means, before feeding the Fuel cell.

According to the invention, a valve system, comprising at least two valves positioned respectively upstream and downstream of the desiccation means, makes it possible to configure the power generation device according to two modes of operation: a mode of production operation - storage of gas and a fuel cell operating mode. These valves are for example three-way valves.

In the gas production-storage operating mode, the valves, configured in a first state, connect in series the gas production means, the drying means before storage under pressure of the gas, and the means of storage under pressure of the gas. This connection makes it possible to store each of the gases produced by electrolysis, then dried and compressed to be stored in a storage tank. In the case of hydrogen gas, it may alternatively be stored in a tank, in the form of metal hydrides, without prior compression.

In the fuel cell mode of operation, the valves, configured in a second state, allow the passage of one of the fuel or oxidant gases through the desiccation means for the supply of the fuel cell. . According to the invention also, the drying means is configured such that, in the fuel cell operating mode, it operates at a temperature at least equal to 60 ° C and at least partially ensures the humidification of the fuel cell. gas passing therethrough in fuel cell operation mode, by at least partial return of the water extracted from the gas flowing through it in the gas production-storage operating mode. In other words, the desiccating means is used as a humidifying means. Thus, the desiccation means has the advantage of providing both desiccation and humidification functions, which simplifies the device for producing electricity by a fuel cell. Correspondingly, the water stored by the desiccant means, during the passage of the wet gas, gas production-storage mode of operation, is at least partly restored to the gas passing through the desiccant means in fuel cell operation mode. Consequently, the at least partial elimination of the water stored by the desiccation means allows automatic maintenance, that is to say without human intervention, of the desiccation means and the maintenance or regeneration of its capacity. desiccation. A beneficial consequence is the increase in the overall energy efficiency of the fuel cell electricity generating device, since the regeneration of the desiccant means is carried out using the free energy lost from the fuel cell.

The humidification mode operation of the desiccation means, at a temperature of at least 60 ° C, allows to desorb the same amount of water than that which is absorbed in operation in drying mode, at a temperature between 5 ° C and 25 ° C. Thus, to be able to desorb the same amount of water absorbed during the storage phase, the temperature of the gas to be humidified must be higher than that of the gas to be dried. A preferred embodiment of the invention is a device for generating electricity in which the desiccating means, at least partially ensuring the humidification of the gas passing through it in fuel cell operation mode, driven by a pump, is configured so that its operating temperature is between 60 ° C and 100 ° C, preferably between 60 ° C and 80 ° C. Indeed, this operating temperature makes it possible to transform the water recovered by the desiccation means into water vapor during the drying step. The preferred temperature range [60 ° C, 80 ° C] corresponds to the usual operating temperatures of a fuel cell. The temperature range [80 ° C., 100 ° C.] corresponds to the operating temperatures at which the membranes of the fuel cells in development tend, as these higher temperatures advantageously make it possible, for example, to reduce the amount of platinum required for operation. of the fuel cell or to cool the fuel cell more easily.

An alternative embodiment of the previous preferred embodiment is an electricity generating device, comprising a cooling circuit of the fuel cell, driven by a pump, wherein the desiccating means, at least partially ensuring the humidification of the gas passing therethrough in the fuel cell operating mode, is configured such that its operating temperature is obtained at least in part by heat exchange with the cooling circuit of the fuel cell. Indeed, this alternative embodiment allows the use of an existing heat source, the cooling circuit of the fuel cell, resulting in an economic advantage. It also makes it possible to reach the operating temperature level, between 60 ° C. and 100 ° C., preferably between 60 ° C. and 80 ° C., necessary for the vaporization of the water stored in the desiccation means. It is further advantageous that the power generation device is configured so that the temperature of the gas entering the desiccating means, at least partially ensuring the humidification of the gas passing through it in the operating mode. fuel, is between 60 ° C and 100 ° C, preferably between 60 ° C and 80 ° C. In other words, the dry and expanded gas entering the desiccation means is preheated to a temperature allowing the vaporization of the stored water. The heating of the gas can be combined with the heating of the desiccation means described above.

In the case where the fuel cell electricity generating device comprises a fuel cell cooling circuit, the electricity generating device is advantageously configured so that the temperature of the gas entering the fuel cell is reduced. drying means, at least partially ensuring the humidification of the gas passing through it in the fuel cell operating mode, is obtained at least partly by heat exchange with the cooling circuit of the fuel cell. This embodiment makes it possible to use an existing heat source, the cooling circuit of the fuel cell, and also makes it possible to reach the temperature level, between 60 ° C. and 100 ° C., preferably between 60 ° C and 80 ° C, necessary for the vaporization of water stored in the desiccant means. According to one embodiment of the invention, the fuel cell electricity generation device comprises a conditioning unit for each of the fuel and combustion gas respectively. Two separate conditioning units thus make it possible to avoid any contact and therefore any chemical reaction between the gases respectively fuel and oxidant before feeding the fuel cell.

This is the case in particular of a device for producing electricity by hydrogen-oxygen fuel cell, in which the fuel gas - gaseous hydrogen - and the oxidizing gas - gaseous oxygen - are conditioned by their respective packaging sets. In the case of a device for producing electricity by hydrogen-oxygen fuel cell, the means for producing hydrogen gas and gaseous oxygen are combined into a single means of production by electrolysis. water from a water storage tank connected to the fuel cell. This means of production by electrolysis of water is the usual and economical means of simultaneous production of hydrogen gas and oxygen gas.

According to another embodiment of the invention, the fuel cell electricity generation device comprises a packaging assembly only for the fuel gas.

This is particularly the case of a hydrogen-air fuel cell, in which only hydrogen gas, produced by electrolysis of water, has a packaging assembly within the meaning of the invention. The air, generally from a compressor, and therefore from a means of production distinct from that of gaseous hydrogen, does not need such a packaging unit.

According to a preferred embodiment of the invention, the desiccating means, intended to extract at least part of the water contained in the gas passing through it, before the gas is stored under pressure, in the production-operating mode. gas storage, is configured such that it is crossed by the same gas in fuel cell operation mode. In other words, the drying means ensuring the drying of the gas passing therethrough, in the gas production-storage mode of operation, before being stored under pressure, ensures the humidification of this same gas after its destocking and before feeding of the fuel cell, in fuel cell operation mode. Thus, the desiccation means provides both desiccation and humidification functions for the same gas. Advantageously, the drying means is therefore traversed by a gas of the same chemical nature, which avoids any risk of chemical reaction within the desiccation means. In the case of a hydrogen-oxygen fuel cell, the gaseous hydrogen and gaseous oxygen circuits are thus perfectly separated. According to another advantageous embodiment of the invention, the desiccating means, intended to extract at least partly the water contained in a first gas passing through it, before storage under pressure of the gas, in operating mode production-storage of gas, is configured such that it is crossed by a second gas in fuel cell operation mode. In other words, the drying means ensuring the drying of a first gas passing through it, in the gas production-storage operating mode, before being stored under pressure, ensures the humidification of a second gas after its destocking and before feeding the fuel cell, in fuel cell operation mode. Thus, the desiccation means provides both desiccation and humidification functions but for different gases. By first gas is meant the gas passing through the desiccant means in gas production-storage mode of operation, and the second gas means the gas passing through the desiccant means in fuel cell operation mode. For example, in the case of a fuel cell of the hydrogen-air type, the means for desiccating the hydrogen gas can ensure the humidification of the compressed air, which in return ensures the drying of the medium. desiccation, which could make redundant the heating of the means of desiccation. As for the hydrogen gas, which is not wetted by its own drying means, it can then be humidified by recirculating the surplus of humid hydrogen gas leaving the fuel cell.

Another preferred embodiment of the invention is a fuel cell electricity generating device, in which the drying means consists of at least one drying column comprising desiccant granules, which is a known and mastered technology.

According to a variant of the previous preferred embodiment, the desiccant granules of a desiccation column are silica gel type, which is a material usually used in this type of application. It is also advantageous for the hydrogen storage means to be in the form of metal hydrides, since this storage means makes superfluous the use of a compressor downstream of the desiccation means.

The invention also relates to the use of a device for generating electricity from a fuel cell electricity generation device according to the invention for a motor vehicle.

The characteristics and other advantages of the invention will be better understood with reference to the appended figures 1 to 3:

FIG. 1 shows the circuit of one of the two feed gases of the fuel cell, in the gas production-storage operating mode, in the case where the fuel cell electricity generation device comprises a set each of the fuel and oxidant gases respectively, FIG. 2 shows the circuit of one of the two fuel cell feed gases, in the fuel cell operating mode, in the case where the device for producing fuel fuel cell electricity comprises a conditioning unit for each of the respective fuel and combustion gases, FIG. 3 shows the circuits of the two fuel cell feed gases, in the fuel cell operating mode, the fuel cell Fuel cell power generation includes a conditioning package only for the fuel gas.

Figures 1 and 2 show schematically the circuit of only one of the two gases respectively fuel and oxidant, this circuit being similar for each gas.

FIG. 1 shows the circuit of one of the two feed gases of the fuel cell, in the gas production-storage operating mode, between the gas production means (1) and the storage means under pressure (5). This circuit is described below with reference to the hydrogen gas supplying a hydrogen-oxygen fuel cell. In addition, the circuit portion in operation, for a given operating mode, is shown in phantom while the non-operating circuit portion is shown in dashed lines.

Hydrogen and gaseous oxygen are produced using the gas production means (1), by electrolysis of the water stored in the water tank (12). The water tank (12) is fed at least in part by a recycle water from the condenser (2) disposed downstream of the electrolyser (1) and a recycle water from the fuel cell (8) . The hydrogen gas, from the gas production means (1) and saturated with water vapor, is partially dried in a condenser (2). Then, the effective desiccation is carried out at room temperature, that is to say between 20 ° C and 25 ° C, in the desiccation means (3). The gas thus dried, originating from the drying means (3), is compressed in a compressor (4), typically between 200 bar and 350 bar for hydrogen gas, and then stored in a pressurized storage means or tank (5) . As an alternative for hydrogen, the use of the compressor (4) may be superfluous if the gas is stored in a tank (5) in the form of hydrides, at a pressure of between 5 bars and 15 bars. Three-way valves (6) and (7), respectively arranged upstream and downstream of the drying means (3), are configured in production-storage operating mode, that is to say they connect in series the means for producing gas (1), the drying means before storage under pressure of the gas (3) and the pressurized storage means of the gas (5).

FIG. 2 shows the circuit of one of the two feed gases of the fuel cell, in fuel cell operating mode, ranging from the pressurized storage means (5) to the fuel cell (8). . As for FIG. 1, this circuit is described below with reference to the hydrogen gas supplying a hydrogen-oxygen fuel cell.

In the fuel cell operating mode, the dry hydrogen gas is removed from its pressure storage means (5), decompressed through an expander (9), this expander being associated with a safety valve (10). disposed downstream of the expander (9). The decompressed dry hydrogen gas is then humidified during its passage through the desiccant means (3) at a temperature of operating between 60 ° C and 100 ° C, preferably between 60 ° C and 80 ° C. This operating temperature is obtained by heat exchange between the desiccant means (3) and the cooling circuit (11) of the fuel cell (8). The liquid of this cooling circuit is driven by the pump (14).

FIG. 3 shows the circuits of the two feed gases of the fuel cell, in the fuel cell operating mode. This is for example the case of a hydrogen-air fuel cell. According to this embodiment, the dry hydrogen gas is removed from its pressure storage means (5), decompressed through an expander (9), this expander being associated with a safety valve (10) disposed downstream of the expander (9). The decompressed dry hydrogen gas is then humidified by recirculation of excess wet hydrogen gas leaving the fuel cell (8). The air, coming from a compressor (13), enters the desiccant means (3) of the hydrogen gas, via the valve (7), to be humidified therein, before supplying the fuel cell (8). ).

This embodiment, comprising a single packaging assembly only for hydrogen gas, in which the hydrogen gas is humidified by its own drying means and the air is moistened by the moist air leaving the battery fuel, via a moisture exchanger, is not shown.

The invention should not be interpreted as being limited to the embodiments, presented above and illustrated in FIGS. 1 to 3, but may be extended to other embodiments, such as by way of example. and in a non-exhaustive way:

a fuel cell electricity production device comprising a desiccation means for a column comprising desiccant granules, other than silica gel type,

a fuel cell electricity generation device comprising a desiccation means comprising a solid phase desiccant material, other than desiccant granules, a fuel cell electricity production device comprising several desiccation and storage means as well as several fuel cells.

Finally, such a fuel cell electricity production device is not limited to the supply of electrical energy for a motor vehicle but can be extended to any device requiring a supply of electrical energy.

Claims

A fuel cell power generation device, comprising:

a means (1) for producing fuel gas and means for producing (1, 13) oxidizing gas, the fuel and combustion gases respectively being intended to feed a fuel cell (8) in which they react chemically with each other for produce electrical energy,

at least one conditioning unit (2, 3, 4, 5, 6, 7, 9, 10) for one of the fuel or oxidant gases, comprising at least one desiccation means (3) intended to extract at least one partly the water contained in the gas passing through it before storage under pressure of the gas, at least two valves (6, 7) respectively upstream and downstream of the drying means (3), at least one pressure storage means gas (5) and at least one humidifying means after destocking and decompressing the gas, -the valves (6, 7), in a first state, for configuring the power generation device in production-operation mode. storing the gas, connecting in series the means for producing (1) the gas, the drying means (3) and the pressurized storage means of the gas (5),

characterized in that the valves (6, 7), in a second state, make it possible to configure the power generation device in fuel cell operation mode, by allowing the passage of one of the fuel or oxidant gases through the desiccant means (3) for feeding the fuel cell (8), and in that the desiccant means (3) is configured such that, in the fuel cell operating mode, it operates at a temperature at least equal to 60 ° C and at least partially ensures the humidification of the gas passing therethrough, by at least partial return of the water extracted from the gas flowing through it in the gas production-storage operating mode.

2- fuel cell electricity generation device according to claim 1, characterized in that the desiccant means (3), at least partially ensuring the humidification of the gas passing through it in the fuel cell operating mode, is configured so that its operating temperature is between 60 ° C and 100 ° C, preferably between 60 ° C and 80 ° C. 3- fuel cell electricity generation device according to one of claims 1 or 2, comprising a cooling circuit (11) of the fuel cell (8), driven by a pump (14), characterized in that that the drying means (3), at least partly ensuring the humidification of the gas passing therethrough in the fuel cell operating mode, is configured such that its operating temperature is obtained at least in part by heat exchange with the cooling circuit (11) of the fuel cell (8). 4- fuel cell electricity generation device according to any one of claims 1 to 3, characterized in that the power generation device is configured such that the temperature of the gas entering the desiccation means (3), at least partially ensuring the humidification of the gas passing therethrough in the fuel cell operating mode, is between 60 ° C and 100 ° C, preferably between 60 ° C and 80 ° C.

A fuel cell electricity generating device according to any one of claims 1 to 4, comprising a cooling circuit (11) of the fuel cell (8) driven by a pump (14), characterized in that the electricity generating device is configured such that the temperature of the gas entering the desiccant means (3), at least partly ensuring the humidification of the gas passing therethrough in the fuel cell operating mode, is obtained at least in part by heat exchange with the cooling circuit (11) of the fuel cell (8).

The fuel cell power generation device of any one of claims 1 to 5, characterized in that the fuel cell power generation device comprises a conditioning assembly (2, 3, 4, 5). , 6, 7, 9, 10) for each of the respective fuel and oxidant gases. 7- Fuel cell electricity generation device according to the claim

6, characterized in that the respectively fuel and oxidant gases are hydrogen gas and oxygen gas. 8- Fuel cell electricity generation device according to the claim

7, characterized in that the means for producing the gaseous hydrogen and the gaseous oxygen are combined into a production means (1) by electrolysis of the water coming from a water storage tank (12) connected to the fuel cell (8) ·

9. A fuel cell electricity generating device according to any one of claims 1 to 5, characterized in that the fuel cell electricity generating device comprises a conditioning unit (2, 3, 4, 5). , 6, 7, 9, 10) only for the fuel gas.

10- Fuel cell electricity generation device according to the claim

9, characterized in that the respectively fuel and oxidant gases are hydrogen gas and air. 11- Fuel cell electricity generation device according to the claim

10, characterized in that the means for producing gaseous hydrogen is a means for producing (1) electrolysis of water from a water storage tank (12) connected to the fuel cell (8). ), and in that the means for producing air is an air compressor (13).

12- fuel cell power generation device according to any one of claims 1 to 11, characterized in that the desiccating means (3) for extracting at least partly the water contained in the gas the passing through, before the storage under pressure of the gas, in the gas production-storage operating mode, is configured such that it is traversed by the same gas in fuel cell operation mode. 13- fuel cell power generation device according to any one of claims 1 to 1 1, characterized in that the desiccating means (3) for extracting at least partly the water contained in a first gas passing therethrough, prior to the gas pressure storage, in the gas production-storage operating mode, is configured such that a second gas is passed therethrough in the fuel cell operating mode.

14. A fuel cell electricity generation device according to any one of claims 1 to 13, characterized in that the drying means (3) consists of at least one desiccation column comprising desiccant granules.

15- fuel cell electricity generation device according to claim 14, characterized in that the desiccant granules of a desiccant column (3) are of silica gel type.

16. A fuel cell electricity generation device according to any one of claims 1 to 15, characterized in that the means for storing hydrogen is in the form of metal hydrides.

17- Use of a fuel cell electricity generation device according to any one of claims 1 to 16 for a motor vehicle.