DE10306342A1 - Electrolysis arrangement for obtaining hydrogen and oxygen from water comprises an electrolysis cell having a current connection, electrolyte supplies , gas compartments, and a housing with a current feed and a gas outlets - Google Patents

Abstract

Electrolysis arrangement (1) comprises an electrolysis cell (3) having a current connection, electrolyte supplies (6a, 6b), gas compartments (7a, 7b), and a housing (2) with a current feed and a gas outlets (8a, 8b). The electrolysis cell is arranged in the housing and one of the gas compartments (7b) is connected to the gas outlet (8b) and the other gas compartment (7a) ends in the inside of the housing. One of the electrolyte supplies starts in the inside of the housing so that the housing acts as an electrolyte and as a gas storage unit.

Description

The invention relates to an electrolysis device, the at least one electrolytic cell with a power connection, at least has an electrolyte supply and two gas discharge lines and one casing with a current feedthrough and two gas outlets having.

With the help of electrolysis can Water or watery solutions high-purity gases can be obtained. When electrolysis of water can oxygen and hydrogen can be obtained from aqueous fluoride solution Fluorine can be obtained from aqueous chloride solution chlorine can be obtained. The high-purity gases obtained in this way can e.g. be used in gas chromatography and spectroscopy. There is also a particularly high level of interest in hydrogen as an energy store, with which fuel cells can be fed.

Research in the field of hydrogen generators has been going on for a long time. For example, from the EP 0 055 134 A1 a hydrogen generator is known in which hydrogen is obtained on the basis of chemical conversion of base metals. However, this is very uneconomical.

From the JP 8 176 873 A and JP 8 193 286 A high-pressure hydrogen generators are known in which a hollow cathode is used for the production of hydrogen. The hydrogen is compressed in the hollow cathode and the pressure built up in this way is used for energy or heat generation.

According to the JP 9 291 386 A are a reaction tank in which the electrolysis takes place and a phase separator tank are arranged one above the other. The oxygen is immediately removed from the reaction tank. The hydrogen is fed to the phase separator tank via a gas line and is discharged from there.

From the US 3,933,614 a high pressure housing for hydrogen generators is known. The metal housing consists of a container open at the top and a lid tightly connected to it. Feedthroughs for the water supply and the oxygen and hydrogen discharge are provided in the cover. The interior of the housing is dimensioned such that an electrolysis cell with an asbestos membrane for separating the half cells fits into the housing and is surrounded by electrolytes. The two half cells are separated from each other in a gas-tight manner. Both the hydrogen and the oxygen are removed directly from the housing.

The US 3,374,158 describes an electrolysis system comprising a plurality of electrolysis cells, in which a part of the gases obtained is returned to the system for cooling and for refilling the electrolyte solution. In addition, the pressure conditions are controlled so that the pressure difference between the two half cells on the membrane is as small as possible.

In the water electrolysis system of US 6,375,812 a closed water circuit is provided for the electrolyte. The non-electrolyzed water is separated from the gases obtained in a phase separator. The water circulates on the one hand with the help of gravitation and on the other hand with the help of the pressure differences that result from the product gas being removed.

From the US 6 3 303 009 a hydrogen generator is known in which water is electrolyzed using a proton exchange membrane. The power supply for the electrolysis reaction is controlled by a computer in such a way that the hydrogen partial pressure remains essentially constant even though hydrogen is removed. In addition, the lifetime of the generator is extended by keeping the pressure difference across the membrane as low as possible.

In the US 5,494,559 describes an electrolysis system in which the electrolysis takes place over a large number of polymer beads which are conductively coated. The electrolysis cell is supplied with electrolyte by a pump. The product gases hydrogen and oxygen are removed via a phase separator.

In the hydrogen and oxygen generator according to the US 5 690 797 is an electrolytic cell immersed in ionized water. Both the oxygen and the hydrogen are removed via separators. A differential pressure regulator ensures that the differential pressure remains essentially constant. It also controls the level of ionized water and uses this information to control pressures and replenish ionized water.

Except for the deployment high purity gases for For the purposes of analysis, the production of hydrogen and its use as an energy storage in the foreground. Especially in Due to the intensified use of renewable energies such as of wind and solar energy it is necessary to have compact electrolysis devices to disposal with the help of the regenerative energies in storable Energies can be converted and stored, whereby the devices simultaneously serve the stored energy to be transported or made available locally.

This task is solved by an electrolysis device according to claim 1.

The device according to the invention is characterized by an extremely compact design. All important components such as the electrolysis cell, electrolyte storage and product gas storage as well as the necessary connections are integrated in a single housing. On the one hand, this makes the device according to the invention easy to transport. By offering the possibility of having both an electrolyte supply and a gas storage device, it can be used in Environments are used in which maintenance is rarely possible or economically sensible. In addition, the device can be used independently since it only requires a power source. The device according to the invention can be connected wherever electricity is obtained, for example, from regenerative energies. With the help of the device according to the invention, this current is converted into energies of chemical form by the electrolysis of water and this energy is stored.

The housing is advantageously suitable for high pressure. This ensures that great Amounts of product gas can be stored. Preferably acts the case around a pressure cylinder. And it can e.g. a conventional one Trade steel pressure cylinders or an aluminum cylinder with kevlar coating, as he e.g. is manufactured by Dynatec, Canada. Even though they resemble To press like steel cylinders, they are comparatively light. Such printing cylinders are therefore particularly suitable for applications the device according to the invention, where easy portability is important. Under high pressure a pressure of 10 bar to over 200 bar is understood here.

By the half cells of at least one Electrolysis cells by means of the at least one electrolyte supply will be flooded, a gas-tight separation of the half cells guaranteed. Because of the extremely high explosiveness of oxyhydrogen, however preferably, two separate electrolyte feeds for the catholyte and the anolyte provided. Particularly in the case of electrolytic cell stacks from a large number of electrolysis cells has also proven advantageous if the two electrolyte supplies are switched so that the Electrolytic cell stack in the countercurrent principle becomes. Among other things, this creates a more homogeneous pressure distribution and heat distribution over the Ensured electrolysis cell stack.

In the at least one electrolytic cell by the ohmic cell resistance Produces heat. It has proven to be advantageous to use this heat by means of passive cooling elements dissipate. Attached to the outer wall of the housing are particularly preferred Cooling fins. In extreme temperature conditions it may be necessary, in addition active cooling measures for example in the form of convection.

In a preferred embodiment a pump is arranged in the at least one electrolyte supply, to pump the electrolyte into the at least one electrolysis cell. It is preferably a circulation pump that has no cavities, so that a complete pressure equalization is guaranteed within the pump is. In this case the circulation pump only those inside the case overcome the prevailing pressure difference in order to Pump electrolyte into the at least one electrolytic cell.

The electrolyte is in certain operating cycles refilled. If necessary, an electrolyte level control can be provided. It should be taken into consideration, that the at least one electrolysis cell stops operating, and there is no longer any electrolyte, but is used up. Because then flows no more electricity in the electrolysis circuit.

Depending on the location of the device according to the invention a continuous flow of electrolyte can also be provided. For that would have to the electrolyte inlet of the housing a high pressure pump can be provided which the electrolyte in the housing under high pressure transported.

When filling with electrolyte must be considered be careful not to put too much electrolyte in the case, because then only a limited volume available as product gas storage would. However, it is also important not to fill in too little electrolyte, otherwise electrolysis would stop prematurely.

In a particularly preferred embodiment, the at least one electrolysis cell is a thin-film cell. Thin film cells are used, for example, in the DE 198 41 302 C2 described. Thin-film cells are characterized in that the two electrodes of a cell are only separated by a capillary gap. Therefore, they have a very low ohmic resistance. In addition, no conductive salt is required for the electrolysis of water. Thin-film cells can be made very small and compact. They also have a very high efficiency due to their high area-volume ratio.

Offer another option for electrolytic cells membrane electrode assemblies (MEA membrane electrode assembly). These are e.g. known from fuel cell technology. You point a membrane with porous Material is coated as an electrode.

Has proven to be particularly advantageous the use of electrically conductive membranes in the electrolysis cells exposed. Polymer electrolyte membranes are particularly preferred. The combination of thin-film cells is very particularly preferred with electrically conductive Membrane.

The thin film cells must be compared to those in the DE 198 41 302 C2 shown thin-layer cells with a liquid channel have a slightly different geometry, since there is a gas-liquid mixture in the half-cells, which must be able to flow freely. Plate-shaped electrodes or membranes should therefore preferably be provided, which are spaced apart, for example with the aid of support points or networks. In addition, it is advantageous not to design the electrolysis cells as rectangular, but circular, so that they form a cylindrical shape when stacked. Cylinders have the advantage that they are less tight surface is available and therefore this shape is suitable for high pressure applications and one cylinder requires less space in the pressure housing.

There is essentially a phase separator from a container, in which the electrolyte settles down and the gas outgasses. Around the electrolyte if possible to be able to use it intensively and one if possible Obtaining pure gas has proven to be beneficial a phase separator for to provide the gas to be stored. This phase separator is on the corresponding gas discharge pipe in front of its mouth in the housing.

To increase the operating time for an electrolyte fill increase, is preferably a further phase separator for the gas to be removed in the corresponding Gas discharge provided. So that the gases are as aerosol-free as possible, a frit can be provided at the output of the respective phase separator be that the gas, but not the electrolyte droplets. If the gas to be stored is hydrogen for use deals in fuel cells, the hydrogen can to some extent contain water vapor. The electrolyte recovered in the separator is returned to the normal electrolyte volume, from where it may have a circulating pump is pumped back into the at least one electrolysis cell.

In a particularly preferred embodiment is at the gas outlets a differential pressure regulator is provided, which serves to control the pressure difference as far as possible within the at least one electrolysis cell to keep low. In electrolysis e.g. of water arise with one volume of oxygen two volumes of hydrogen. By for the to be saved Gas one if possible great Volume is held and for the one to be discharged Gas one if possible small internal volume provided, it is ensured that a sufficient Back pressure is built up. about the differential pressure regulator is only discharged as much gas to be discharged that the differential pressure remains constant. Overall, this will result in the at least one electrolysis cell on the intermediate membrane has a pressure difference maintained from essentially zero. This increases significantly the lifespan of the electrolytic cell.

Particularly preferred because of its compact design is the embodiment, where the housing has a lid, in the current feedthrough, the electrolyte inlet and the two gas outlets are integrated and on which the at least one electrolysis cell is attached. This embodiment has the advantage that all essential components are easily accessible and can be easily installed and removed.

The device according to the invention can be used as a disposable device be trained, which were filled with electrolyte before use is. This fixed supply of electrolyte would not be replenished. After use or after the product gas obtained has been emptied, it could either disposed of or refilled after opening the housing. In a preferred embodiment points the case an electrolyte inlet to the device during the Refill operation with electrolyte to be able to or to easily the device after use fill to be able to.

The invention is based on the following Figures for the example of water electrolysis will be explained in more detail.

Show it:

1 a schematic diagram of a first embodiment of the device according to the invention;

2 a schematic diagram of a further embodiment of the device according to the invention;

3a a section through an electrolysis device;

3b a section through an electrolysis device with continuous electrolyte supply;

4a an exploded view of an electrolytic cell;

4b the elements of the electrolytic cell in plan view;

5a a section through an electrolytic cell;

5b a section through a further electrolytic cell;

6 the dependence of the hydrogen pressure and the decomposition voltage on the electrolysis time.

In 1 is shown schematically a first embodiment of the device according to the invention. The electrolysis device 1 consists essentially of a housing 2 in which an electrolytic cell 3 is arranged from two half cells. Also located in the housing 2 electrolyte 4 , ie water, and gas to be stored 5 , ie hydrogen. The electrolytic cell 3 has two separate electrolyte feeds 6a and 6b for each half cell. It also has two gas discharges 7a and 7b on, the gas discharge 7a inside the case 2 ends and the gas discharge 7b with the gas outlet 8b connected is. About gas discharge 7b and the gas outlet 8b the oxygen generated in one half cell is removed directly. About gas discharge 7a The hydrogen produced in the other half cell penetrates inside the housing 2 , There it can be enriched or via the gas outlet 8a be dissipated.

The arrangement in 2 essentially agrees with that in 1 match. There are also two pressure gauges 10a and 10b as well as a valve 9 , The pressure gauge is used to measure the hydrogen partial pressure; the pressure gauge 10b is used to measure the difference between the hydrogen partial pressure and the oxygen partial pressure. About the valve 9 the discharged oxygen flow can be regulated.

The volume of a half cell and the gas discharge correspond to the volume of oxygen 7b and the gas outlet 8b , The hydrogen volume corresponds to the volume of a half cell plus the volume of the gas discharge 8a in addition to the interior volume of the housing minus the volumes of the electrolytic cell and water 4 , Since the electrolysis of water produces two parts of hydrogen per part of oxygen and the oxygen is continuously removed while the hydrogen is being stored, this certain volume ratio ensures that a sufficient oxygen back pressure can build up to the hydrogen pressure. Deviations are reported via the valve 9 and the meter 10b regulated. These regulated pressure conditions ensure that within the electrolytic cell 3 , namely on both sides of the membrane, the same pressure prevails, so the pressure difference is minimal. As a result, electrolysis cells with mechanically less stable membranes can also be used.

3a shows an electrolysis device 1 on average. In a high pressure cylinder 26 is an electrolytic cell stack 20 arranged by means of power connections with an external power supply 31 connected is. In addition, the electrolytic cell stack has 20 an electrolyte supply 35 on that in the water 4 protrudes and a circulation pump 25 having. The circulation pump is a low pressure pump for pressures <10 × 10 ⁵ Pascal. At the electrolytic cell stack 20 it is a bipolar arrangement. The individual intermediate cells are in the electrical field between the anode 21 and cathode 22 polarized. There is therefore no need for an additional contact for each cell, but only one contact for the anode 21 and a contact for the cathode 22 , At the gas discharge lines 38 and 37 is a phase separator 23 arranged for the separation of the gaseous electrolysis products from the electrolyte, ie hydrogen or oxygen and water. Two separation units are provided for one and the other electrolysis product. About the derivative 41 the recovered electrolyte becomes the electrolyte storage 4 fed. The electrolysis product to be stored, e.g. B. hydrogen, is via the gas discharge 36 the inner case 2 supplied the other electrolysis product, e.g. B. Oxygen, is through the gas outlet 37 dissipated. A differential pressure meter and controller are connected to the gas outlets 24 on. It has an outlet 32 for the stored electrolysis product and an outlet 33 for the unsaved electrolysis product. The connections for both the electricity and the gases are in the cover 27 integrated. This contributes to a compact design of the entire device. To cool the entire device, it has cooling fins on the outside of the housing 28 on.

In the 3b device is compared to that in 3a Modified in such a way that an external electrolyte storage tank 40 is provided, from which by means of an external high-pressure electrolyte feed pump 39 and an external high pressure electrolyte feed 38 continuously electrolyte 4 is refilled.

One operates the device 1 As a storage for the hydrogen, a circulation pump must permanently 25 be used for the water cycle. Because the extracted oxygen does not build up a sufficient pressure drop to allow the water to enter the electrolysis cells by itself 20 pull up. If you do not store the hydrogen, but also continuously discharge it, you only need a circulation pump for as long 25 until the electrolytic cell stack 20 is sufficiently wet and sufficient hydrogen is produced that a sufficient pressure difference builds up when the hydrogen is released. Then you would the electrolyte supply 35 bypass to the circulating pump 25 to get around.

With a higher discharge pressure, the circulation pump can be used 25 also replace with a piston assembly. The piston would then be displaced by the hydrogen pressure building up and would press the water into the electrolysis cells.

With electrolysis cell stacks 20 the electrolytic cell stack should consist of a very large number of electrolytic cells 20 are supplied with electrolyte according to the countercurrent principle in order to prevent the electrolyte pressure from dropping too much via the stack.

The in the 3a and 3b The device shown is designed to be operated at up to 200 bar.

In 4a the structure of a thin-film electrolysis cell can be seen, which was specially adapted for use in the electrolysis device according to the invention. It is composed of two bipolar plates 11 , a channel plate 13 for the cathode 22 and a channel plate 14 for the anode 21 , Between the individual plates 11 . 13 . 14 are seals 12 arranged. Between the channel plates 13 . 14 is an ion-conductive polymer membrane 17 gastight with a seal 12 arranged. There is a porous electrode on it 16 , which in the present case consists of porous nickel on nickel fabric. As a spacer between the electrodes 10 or conductive membrane 17 and the bipolar plates 11 is also a spacer 15 provided from a fabric. This fabric can be electrically insulating or conductive. If it is electrically insulating, then the electrode must 16 via a separate contact with the corresponding plate 11 get connected.

In 4b the elements just explained can be seen in the top view. The membrane 17 should be electrically conductive and mechanically stable. Therefore, one likes to use composite membranes, for example made of Kevlar from Dupont. The membranes can be reinforced with an insulated reinforcing fabric. This reinforcing fabric is also possible made of kevlar. If it is a polymer electrolyte membrane, it can also consist of a polytetrafluoroethylene with sulfone groups, for example from Nafion from Dupont. If, as in the present example, a membrane electrode arrangement is used, the porous electrode can be used 16 also consist of soot, which is glued with polytetrafluoroethylene. Another than 16a electrode shown consists of fiber material such as graphite felt. The spacer 15 doesn't just have to be fabric. It can also look like how 15a shown to act as a spacer with fluid guidance.

In the electrolysis of fluorine or Chlorine can the same membranes are used as for the hydrogen electrolysis. However, one should look for use the electrodes titanium. With chlorine you should also Use dimensionally stable anodes as used in chlor-alkali electrolysis are known. With the help of the device shown can the electrolysis of heavy water can also be made deuterium. However, it must be considered when powering the electrolytic cells that heavy water has a higher decomposition voltage than normal water.

Except for titanium, which is easy to etch, like this that a rough and very large surface Stainless steel is also preferred as the electrode material used. Because stainless steel is relatively cheap and light on conventional Kind of edit. Moreover it is mechanically and chemically resilient. Stainless steel also shows usually nickel content, which has a positive effect on the electrode properties impact.

For better understanding is in the 5a and b a section through two electrolytic cells. According to the electrolytic cell 5a through an electrically conductive membrane 17 between two bipolar plates 11 is arranged, two half cells formed. The conductive membrane 17 has a porous electrode on both sides. The cathodic half cell is a porous electrode 16a made of graphite felt with catalyst covering, e.g. B. platinum. Alternatively, a porous electrode could be used 16 be made of porous nickel on nickel fabric. The anodic half cell is a porous electrode 16 made of porous nickel on nickel fabric. As a spacer between the membrane 17 with the electrodes 16 and 16a as well as the plates 11 that serve as an anode or cathode are spacers 15 arranged from fabric. The spacers are necessary so that it is under the influence of the high internal pressure inside the housing 2 there are no short circuits. Nevertheless, they allow the gas-liquid mixture in the half cells to flow as undisturbed as possible.

The electrolytic cell 5b differs from that in 5a in that the electrically conductive membrane 17 only on one side with a porous electrode 16a is made of fiber material. The plate is in the other half cell 11 covered with a porous surface. In particular, anodes made of chemically resistant materials such as titanium can be produced from solid material by etching, roughening and similar methods for surface modification.

Example 1:

For hydrogen production by electrolysis of distilled water is a pressure vessel one Volume of 31.4 l initially with 4.7 l of distilled water. This corresponds a share of 15% of the pressure vessel volume. After electrolysis there remains a residual volume of approx. 0.5 l of distilled water in the Pressure vessel.

The electrical thin-film cells used for the electrolysis have electrodes with a diameter of 80 mm, each with an active area of 5.3 cm ² . Cathodes and anodes are fluidly separated from each other by polymer electrolyte membranes made of Nafion 117 ^® from DuPont de Nemours. The cell stack consists of 29 bipolar cells, which leads to a construction volume of the cell stack of approx. 0.7 l. The cathode and anode areas each measure 149 cm ² .

The pressure differences within the Cells are powered by a company’s differential pressure meter and controller BRONKHORST, Netherlands, model "ELPRESS" actively regulated. The gas-liquid separators contain devices for the catalytic removal of the in the Anolyte dissolved oxygen to a platinum black catalyst.

With a volume of the cell stack of 0.7 l, the hydrogen to be stored has a storage volume of 26.0 l available. Converted to normal temperature and pressure, the hydrogen is produced at a rate of 25 l / h. This corresponds to 1.1 mol / h. The selected current density of 400 mA / cm ² by means of direct current, for. B. from a photovoltaic system or a wind turbine.

In 6 the calculated course of the increase in the hydrogen pressure is shown with the progress of the analysis. Accordingly, a hydrogen pressure of 200 · 10 ⁵ Pa is reached after approx. 170 h. At the same time as the gas pressure increases, the theoretical decomposition voltage in the individual cells increases from 1.23 V to 1.33 V. The pressure dependence of the decomposition voltage was determined using the Nernst equation for hydrogen as a real gas using the Van der Waals equation calculated. The high-pressure hydrogen generator described here can store a constant current of approx. 60 A for approx. 211 h via electrolysis. Assuming an electrolysis voltage of approx. 1.8 V per cell (corresponds to a clamping voltage of the cell stack of 52 V), this corresponds to the storage egg electrical energy of 655 kWh in a volume of 5.3 m ³ hydrogen gas at normal temperature and pressure.

At the beginning of the electrolysis, the pressure in the pressure vessel is 1 · 10 ⁵ Pa with a storage volume of 26.0 l. At the end of the electrolysis after 210 hours, 0.5 l of water remain in the container and the hydrogen pressure has risen to 256 · 10 ⁵ Pa. Therefore, the pressure vessel should be designed with an initial water volume of 15% of the total pressure vessel volume for a maximum operating pressure of 260 · 10 ⁵ Pa.

Example 2

The pressure vessel has an internal volume of 106 l. It is initially filled with 17.9 l of distilled water, which corresponds to 15% of the pressure vessel volume. After the electrolysis, a residual volume of approx. 1.6 liters of distilled water remains in the pressure vessel. A storage volume of 88.5 l is thus available for the hydrogen to be stored. Converted to normal pressure and normal temperature, hydrogen is produced at a current density of 400 mA / cm ² at a rate of 46 l / h or 2.1 mol / h. The direct current is made available from a photovoltaic system or a rectified external power source such as a wind turbine.

As in Example 1, the electrolytic thin-film cells have electrodes 80 mm in diameter, each with 5.33 cm ^{2 of} active area. As in Example 1, cathodes and anodes are also separated from one another by polymer electrolyte membranes made from Nafion ^117® from DuPont de Nemours. In the present case, the cell stack is composed of 104 bipolar cells. This leads to a construction volume of the cell stack of approx. 1.1 l. However, the cathodes and anode area are respectively 275 cm ² .

The pressure differences within the Cells are made with a differential pressure meter and controller of the "ELPRESS" model from BRONKHORST, NL actively regulated. The gas-liquid separators included Devices for the catalytic removal of the oxygen dissolved in the anolyte a platinum black catalyst.

The high-pressure hydrogen generator described here can store a constant current of 110 A for approx. 380 hours via electrolysis. Assuming an electrolysis voltage of approx.1.8 V per cell (corresponds to a clamping voltage of the cell stack of 187 V), this corresponds to the storage of electrical energy of 7,800 kWh in a volume of 17.8 m ^{3 of} hydrogen gas (at normal pressure and normal temperature) ,

At the start of the electrolysis, the pressure in the pressure vessel is 1 · 10 ^{1 5} Pa with a storage volume of 106.0 l. At the end of the electrolysis after 380 h, 1.6 l of water remain in the container and the hydrogen pressure has risen to 247 · 10 ⁵ Pa.

Claims (13)

Electrolysis device ( 1 ), having at least one electrolysis cell ( 3 ) with a power connection, at least one electrolyte supply ( 6a . b ) and two gas discharge lines ( 7a . b ) and a housing ( 2 ) with a feedthrough and two gas outlets ( 8a . b ), the at least one electrolytic cell ( 3 ) in the housing ( 2 ) is arranged, one of the gas discharge lines ( 7b ) with one of the gas outlets ( 8b ) is connected, the other gas discharge ( 7a ) ends inside the housing and the at least one electrolyte supply ( 6a . b ) begins inside the housing so that the housing ( 2 ) serves both as an electrolyte and as a gas storage. Device according to claim 1, characterized in that the housing ( 2 ) is suitable for high pressure. Device according to claim 1 or 2, characterized in that the housing ( 2 ) around a pressure cylinder ( 26 ) acts. Device according to one of claims 1 to 3, characterized in that on the housing ( 2 ) passive coolant ( 28 ) are provided. Device according to one of claims 1 to 4, characterized in that two electrolyte supplies ( 6a . b ) are provided, one as a catholyte supply ( 6a ) other than the anolyte supply ( 6b ) serves. Device according to one of claims 1 to 5, characterized in that in the at least one electrolyte supply ( 6a . b ) a pump ( 25 ) is arranged. Device according to one of claims 1 to 6, characterized in that the at least one electrolytic cell ( 3 ) is a thin-film cell. Device according to one of Claims 1 to 7, characterized in that the at least one electrolysis cell ( 3 ) is an arrangement with an electrically conductive membrane. Device according to one of claims 1 to 8, characterized in that it has a phase separator ( 23 ) for the gas to be stored ( 5 ) provides. Device according to one of claims 1 to 9, characterized in that a further phase separator ( 23 ) is intended for the other gas. Device according to one of claims 1 to 10, characterized in that a differential pressure regulator ( 24 ) is provided to measure the pressure difference within the at least one electrolytic cell ( 3 ) to be kept as low as possible. Device according to one of claims 1 to 11, characterized in that the housing ( 2 ) a lid ( 27 ) in which the current feedthrough, the electrolyte inlet ( 38 ) and the two gas outlets ( 8a . b ) are integrated. Device according to claims 1 to 12, characterized in that the housing ( 2 ) an electrolyte inlet ( 35 ) having.