Hydrogen storage cell for storing hydrogen in a metal hydride and hydrogen storage unit with several hydrogen storage cells

Abstract

A hydrogen storage cell (10) for storing hydrogen in a metal hydride comprises a base body (12) with an upwardly open receiving space (14), a cover layer (28) for closing the receiving space (14), a metal hydride layer (16) in the receiving space (14), and a pressing element (18) in contact with the metal hydride layer (16). The pressing element (18) exerts a force on the metal hydride layer (16). A gas space (26) formed in the receiving space (14) for receiving hydrogen is separated from the metal hydride layer (16) by the pressing element (18). A hydrogen storage unit (50) for storing gaseous hydrogen has a plurality of hydrogen storage cells (10) that are fluidically interconnected in such a way that gas exchange between the storage cells (10) is possible.

Description

The present invention relates to a hydrogen storage cell for storing hydrogen and a storage unit composed of a plurality of hydrogen storage cells.The construction of typical hydrogen storage units, also those of metal hydride storage units, generally consists of a cylindrical pressure tank. Current hydrogen pressure accumulators consist of steel and / or composite materials and are of cylindrical shape, which have considerable disadvantages in relation to the converted volume. In the case of metal hydride storage tanks, cooling coils are provided for tempering the metal hydride in order to quickly conduct away the temperatures which are produced in the metal hydride during charging and discharging with hydrogen. However, this leads to a low packing density internally and externally, due to the space requirement of the cooling coil in the storage material and the round design. At the same time, the cooling contact surface with respect to the metal hydride is limited to the surface of the cooling coil.Heat exchange has heretofore been the most challenging issue in the development of memories. There are approaches to enlarging this surface by introducing different heat-conducting structures into the metal hydride for heat conduction. For example, the heat exchange is realized by individual shell-and-tube heat exchangers designed for the respective store. The construction of these memories is very complex and expensive in practice and makes scalability and mass production difficult. The power values are thereby limited. In addition, all of the profiles and structures incorporated reduce the amount of metal hydride that can be incorporated.Thus, there is a great need to provide an improved hydrogen storage device which has particularly good heat dissipation capability and which is easily scalable in size.The object is achieved with a hydrogen storage cell having the features of claim 1 and with a hydrogen storage unit having the features of claim 12.In one aspect, the present invention relates to a hydrogen storage cell for storing hydrogen in a metal hydride, comprising a base body having an upwardly open receiving space; a cover layer for closing the receiving space; a metal hydride layer in the receiving space; a pressing element in contact with the metal hydride layer, wherein the pressing element exerts a force effect on the metal hydride layer and a gas space or hydrogen space for receiving hydrogen is formed in the receiving space, wherein the gas space or hydrogen space is separated from the metal hydride layer by the pressing element.In a further aspect, the invention relates to a hydrogen storage unit for storing gaseous hydrogen, having a plurality of hydrogen storage cells which are fluidically interconnected in such a way that gas exchange is possible between the storage cells, wherein the storage cells are stacked one above the other.Preferred embodiments of the invention are described in the dependent claims. It is understood that the features mentioned above and those still to be explained below can be used not only in the respectively specified combination, but also in other combinations or alone, without departing from the scope of the present invention.According to the invention, the hydrogen storage cell is stored in a metal hydride material which is contained in a metal hydride layer. The hydrogen is not present in gaseous form within the metal hydride. This leads to a significantly higher volumetric energy density of 21.5 kg / m 3 at low pressures in the range of 5 bar to 50 bar, preferably to 30 bar. This enables the hydrogen to be stored directly from an electrolysis without intermediate compression and offers the same energy content as in a comparable 350 bar compressed gas storage. One possible metal hydride is supplied under the trade name Hywrilloy C, it is a low-temperature AB 2- type. The composition comprises Mn (51.8 wt %), Fe (2.9 wt %), Ti+Zr (29.8 wt %), Ti (27 wt %), Zr (2.8 wt %), V+Fe (17 wt %), and V (14.1 wt %). The storage capacity is about 1.8% by weight, i.e. 18 g of H2 can be stored in one kg of Hywrilloy C. The greatest advantage of the material lies in the operating temperature and in the operating pressure between 5*10 5 Pa-27*10 5 Pa (5-27 bar) at 20° C. The metal hydroxide can thus be operated under standard conditions. There are also alternative metal hydrides which can be used in this memory, for example Fe+Ti or La+Ni.Since the metal hydride layer and the metal hydride contained therein expand when the hydrogen is stored in the layer, it is held in the shape by the pressing element and its exerted force action and pressed into the receiving region. Metal hydride can thus also be present in loose form or as a powder. It cannot extend out of the receiving space and also cannot substantially increase its volume. This has the advantage that the hydrogen space remains substantially constant on the side facing away from the metal hydride. The hydrogen space serves for introducing the hydrogen and for distributing the hydrogen into the metal hydride layer. Thus, a good distribution is reliably provided even during the filling or removal of the hydrogen. In addition, an improved heat transfer takes place between the metal hydride or metal hydride layer and the base body.By forming the hydrogen storage cell with a metal hydride layer, a large area is formed over which heat can be dissipated or heat can be absorbed. This has proved to be advantageous in practical use.According to the invention, the construction which is substantially layer-like offers good modularity. Thus, a plurality of hydrogen storage cells can be combined and assembled with one another, so that scaling up to larger units is easily possible. The memory cells may be stacked, for example.Since a major problem in the storage of hydrogen is the heat transfer and dissipation of heat, the configuration with a layer of metal hydride has proven advantageous, in particular when it is pressed or compressed.In a preferred embodiment of the hydrogen storage cell, the base body is formed such that it comprises aluminum. For example, it may be formed entirely of aluminum. An alloy containing aluminum as material for the base body is preferred. Particularly preferably, an alloy of Al Mg Si1 has been formed as suitable for practical use. Such an aluminum corresponds to EN AW 6082. This material, at 220 W / (m * K), offers a 10-fold better thermal conductivity than stainless steel. The heat from the metal hydride layer can thus be introduced into the base body and distributed.In a preferred embodiment of the hydrogen storage cell, the base body has a substantially rectangular base area. Here, substantially rectangular means that the corners can be rounded in order to avoid damage to the base body and its outer surfaces in practice and to reduce a possible risk of injury. The base area of the base body of the hydrogen storage cell is preferably square. The height of the base body is at most 20% of the smaller side surface of the base body. A height of the base body which has at most 15% of the length of the smallest side length of the base body is particularly preferred, further preferably at most 10% and particularly preferably at most 5%. In this way, a rather flat base body is formed, so that good heat dissipation can take place, in particular because the distance between the metal hydride layer and the environment is small.A hydrogen storage cell having a rectangular base body which is considerably wider and longer than high offers the possibility of stacking a plurality of hydrogen storage cells. A configuration of the storage cell as a flat layer structure is preferred. In this way, almost any number of hydrogen storage cells can be combined with one another. In this way, hydrogen storage units can be formed if they are at least fluidically connected in such a way that gas exchange of the hydrogen between the individual cells is possible.In a preferred embodiment, the base body of the hydrogen storage cell has a cooling chamber on its underside, which cooling chamber is preferably designed as a cooling channel. This cooling channel particularly preferably runs in meandering fashion. The cooling chamber or cooling channel is particularly preferably formed in the base body on its underside. Since the metal hydride layer is arranged close to the underside of the base body, good heat transfer takes place between the metal hydride layer and a coolant, which can flow in the cooling channel or cooling space. Cooling space or cooling channel can be open toward the underside. They are then preferably closed by a seal or sealing plate.Preferably, the cooling space has a coolant inlet and a coolant outlet which are spaced apart from one another in such a way that flowing coolant flows through the cooling space between the coolant inlet and the coolant outlet. The coolant for heat exchange, which can be used both for cooling and for heating the metal hydride layer, thus flows through the coolant inlet into the cooling space and out again through the coolant outlet. Preferably, the inlet and outlet are arranged such that at least 80% of the cooling space is flowed through by an entering coolant before it exits the cooling space again. Preferably, the coolant inlet and the coolant outlet are arranged in the cooling space at opposite ends. In a configuration as a cooling channel, inlet and outlet are located at the respective ends of the cooling channel. This ensures that coolant flows through as large a surface of the base body as possible and thus good heat exchange can take place.In a preferred embodiment, the pressing element comprises a pressing plate and / or a resilient element. For example, the pressing element can be formed by a pressing plate which is pressed against the metal hydride layer by a resilient element. Alternatively, the pressing element can be formed, for example, by a non-woven fabric, itself be resilient or by a combination of pressing plate and flat springs, compression springs or similar resilient elements. In addition to pressing the metal hydride layer against the underside of the receiving space, the pressing element also has the task of forming a gas space, gas distribution space or hydrogen space in order to distribute the inflowing gas, i.e. the hydrogen. For this reason, a pressure plate has a plurality of openings which allow hydrogen to flow through the plate.On the other hand, the pressing plate is formed so that the metal hydride remains in the metal hydride layer and does not leak into the hydrogen space. The metal hydride is retained by the pressure plate.This effect can be supported by a filter element which is preferably arranged in the receiving space between the gas space and the metal hydride layer. The filter element is designed to at least reduce, as far as possible prevent, a transfer of material from the metal hydride layer into the gas space. The filter element is preferably integrated into the pressing element. For example, the openings in the pressing element can be regarded as a filter element.In a preferred embodiment, the filter element is a metallic fabric layer, a paper filter layer, a plastic filter layer or a combination of the filter possibilities mentioned here. For example, the filter element can be applied to the pressing element.The use of a filter element is suitable in particular when the metal hydride has been introduced into the metal hydride layer in poured form. In this case, a metal hydride dust can be produced, which is largely retained by the filter element.Alternatively and likewise preferably, the metal hydride can be present in the metal hydride layer in pressed form or in the form of pellets, partly admixed with additives such as graphite. This pellet form is generally not stable and decomposes over time by the volumetric work of the metal hydride. Since the metal hydride is held permanently under mechanical pressure by the pressing element or a resilient element, the starting material can be introduced in pressed or loose form. The metal hydride can be introduced into the metal hydride layer, for example, by filling, regardless of whether it is present in the form of pellets.In a preferred embodiment, the base body has a gas port for the supply and removal of the hydrogen. The gas port is connected to the gas space of the receiving space. The gas port can be realized, for example, by a bore. This bore extends through the base body of the hydrogen storage cell, but not through the metal hydride layer. Between the bore of the gas port and the gas space, a preferably transverse connection in the form of an opening or a bore can be provided. Alternatively, a distribution space extending beyond the dimensions of the receiving space is provided, into which the gas port extends.In a preferred embodiment, the gas port comprises a filter. This can be formed from a sintered material, for example. It is also possible to use particle filters at the outlet of the respective storage cell or at the outlet of a hydrogen storage unit, in which the individual gas ports converge. The particulate filter needs a suitable pore size to retain small amounts of fine particles that may be present in the receiving space.In a preferred embodiment, pressures of at most 100 bar, preferably at most 50 bar, further preferably at most 30 bar prevail in the hydrogen storage cell. Particular preference is given to pressures for the hydrogen storage cell of not more than 20 bar. In an equally preferred embodiment, the pressures occurring can be between about 5 bar and 25 bar.Owing to the low pressures, aluminum can preferably be used as material for the hydrogen storage cells.A hydrogen storage unit formed from a plurality of hydrogen storage cells provides, for example, that the individual storage cells are stacked. They are thus arranged one above the other.In a preferred embodiment of the hydrogen storage unit, an upper end plate is provided which covers the upper hydrogen storage cell. The cover layer for closing the receiving space can be formed by this upper end plate. Preferably, a seal is inserted between the base body of the hydrogen storage cell and the upper end plate. In the case of the stack of a plurality of hydrogen storage cells, the covering layer can also be used to close an optional open cooling duct on the underside.A lower end plate of the hydrogen storage unit covers the underside of the base body of the hydrogen storage cell. This is suitable in particular when the cooling chamber on the underside of the base body is open downward. The cooling chamber or cooling channel is then closed by the end plate. The lower end plate can simultaneously serve as a base or as a stand.The upper end plate preferably has connections for coolant in order to supply the coolant to the coolant inlet and coolant outlet of the storage cells. The connections for coolant are preferably aligned with the coolant inlets and coolant outlets. The coolant inlets and coolant outlets of the respective hydrogen storage cells can be connected to one another, so that a connection for coolant can be provided on the upper end plate, through which connection all hydrogen storage cells can be supplied. Preferably, the upper end plate also has a gas port for hydrogen which is connected to the gas port of the upper hydrogen storage cell. In this way, hydrogen reaches the upper and through further connections between the individual storage cells reaches all storage cells. The gas connection is preferably aligned with the gas ports of the storage cells.In a preferred embodiment of the hydrogen storage unit, the base body has a substantially square base surface, wherein the height of the base body of the individual hydrogen storage cells is dimensioned such that a hydrogen storage unit having 10 hydrogen storage cells, an upper end plate and a lower end plate forms a cube. Such a hydrogen storage unit is thus in the form of a cube. Alternatively and preferably, the individual hydrogen storage cells are dimensioned such that a hydrogen storage unit having 10 hydrogen storage cells without end plates has the shape of a cube.The invention will be described and explained in more detail below with reference to some selected exemplary embodiments in conjunction with the accompanying drawings. The following are shown: FIG. 1 shows a basic design of a hydrogen storage cell in section; FIG. 2 shows a hydrogen storage cell in a view from above and below; FIG. 3 shows a hydrogen storage unit having 10 hydrogen storage cells; FIG. 4 is a detailed drawing of the hydrogen storage unit of FIG. 3 ; FIG. 5 shows a cubic hydrogen storage unit having 10 hydrogen storage cells; and FIG. 6 shows several embodiments of hydrogen units that are modular in construction and coupled to form a larger unit.FIG. 1 shows the basic structure of a hydrogen storage cell 10 having a base body 12 which has an open receiving space 14. The receiving space 14 is open at the top. A metal hydride layer 16 is arranged in the receiving space 14, which comprises introduced metal hydride in pressed or loose form. Above the metal hydride layer 16, a pressing member 18 is disposed which is in contact with the metal hydride layer and exerts a force on the metal hydride layer 16. The pressing element 18 comprises a pressing plate 20 and a resilient element 22, which is formed by a plurality of flat springs 24. Above the pressing element 18, a gas space 26 is formed, which is part of the receiving space 14. The gas space 26, which is also referred to as a hydrogen space, serves for distributing the hydrogen flowing into the hydrogen storage cell 10 into the metal hydride layer 16.The base body 12 of U-shaped cross section and the receiving space 14 extending therein are closed in the upward direction by a cover layer 28.FIG. 2 shows the base body 12 of the hydrogen storage cell 10 from above (right) and from below (left). On an underside 30 of the base body 12, a cooling space 32 in the form of a cooling channel 34 formed in a meandering fashion is provided. The cooling channel 34 is introduced into the underside of the base body and is open toward the bottom, so that its open side terminates with the underside 30 of the base body 12. Thus, the cooling channel 34 may be closed by applying a cover plate or cover layer 28. An inlet is provided at both ends of the cooling channel 34, one inlet serving as coolant inlet 36 and the other as coolant outlet 38. The two accesses are preferably arranged in two diagonal corners on the base body. In this way, coolant may flow through the cooling passage 34.A gas port 40 can be seen on the underside 30 and on the upper side of the storage cell. It extends through the base body 12 in the form of a bore. The gas port 40 is fluidically connected to the gas space 26 which has a distribution pocket 42 such that incoming hydrogen can pass via the distribution pocket 42 into the gas space 26. The gas space 26 with its distribution pocket 42 is thus larger in terms of area than the part of the receiving space 14 in which the metal hydride layer 16 is arranged. In this way, the gas port 40 can extend through the base body 12 and establish a connection to the gas space 26 without running directly through the metal hydride layer 16.FIG. 3 shows a section through a hydrogen storage unit 50 which is formed from 10 hydrogen storage cells 10. The hydrogen storage cells 10 are bounded at the bottom by a lower end plate 52 in the form of a base 54. At the upper end, the hydrogen storage cells 10 are covered and bounded by an upper end plate 56. Seals 58 are provided between the respective hydrogen storage cells 10, so that firstly the cooling channels 34 can be sealed off and secondly the receiving space 14 can be sealed off.A detailed view in the hydrogen storage unit 50 is shown in FIG. 4. Here, the lower end plate 52 and two upwardly adjoining hydrogen storage cells 10 are shown. The lower end plate 52 is covered with the seal 58 that seals the cooling passage 34 of the overlying hydrogen storage unit 50. The cooling channel 34 is let into the underside 30 of the base body 12. In the accommodating space, a metal hydride layer 16 is disposed to accommodate the hydrogen in the metal hydride contained therein. The metal hydride layer 16 is arranged close to the cooling channel 34, so that a good heat exchange can take place over a large area due to the rectangular base area of the base body 12.Above the metal hydride layer, the pressing element 18 is shown with pressing plate 20 which presses on the metal hydride layer 16. This has the advantage that the metal hydride can also be introduced into the metal hydride layer in the form of a loose fill, since the loose fill is compressed via the pressing element 18. The pressing element 18 comprises a resilient element 22, which is not visible here, but ensures the pressing pressure in the direction of the metal hydride layer 16.A seal 60 is arranged above the pressing element 18 and seals the receiving space 14. This seal 60 abuts on the upper side of the base body 12.A cover layer 28 closes the base body 12 and its receiving space 14 in the upward direction. Above the cover layer 28 is arranged the seal 58, which closes and seals the cooling channel 34 of the hydrogen storage cell 10 lying above it.Due to the inclusion of the hydrogen within the metal hydride of the metal hydride layer 16, the prevailing pressure is lower by a factor of 10 than in conventional pressure accumulators. This enables a rectangular design of the base body 12, as shown here. The integrated thermal management also makes it possible to reduce unwanted pressure peaks caused by temperature changes during charging and discharging with hydrogen. In addition, the rectangular design has a higher volumetric packing density than cylindrical reservoirs. In comparison, this packing density is about 22% lower in cylindrical, juxtaposed pressure tanks.FIG. 5 shows a hydrogen storage unit 50 having a plurality of hydrogen storage cells 10, which is formed as a cubic block. In the perspective view, it can be clearly seen that two connections 62 for coolant are provided in the upper end plate 56. By means of these connections 62, a coolant is supplied to and flowed through the cooling channels of the individual hydrogen storage cells 10 for heat exchange purposes. A gas port 64 for hydrogen in a third corner of the top end plate 56 is in communication with the gas ports of the hydrogen storage cells 10 so that the individual hydrogen storage cells 10 are supplied with hydrogen. By means of the gas connection 64, both a charging and a discharging of the individual storage cells of the hydrogen storage unit 50 with hydrogen take place.The hydrogen storage cell 10 described in the present invention preferably has a capacitance of 100 g H2. This corresponds to 5.5 kg of metal hydride and preferably represents a type of basic module as a basis for a scalable construction of a hydrogen storage device.In FIG. 6, several embodiments of hydrogen storage units 50 are shown, which are formed modular from several hydrogen storage cells 10, i.e. several basic modules. This is possible since the hydrogen storage cells 10 can be combined with one another almost as desired, so that storage units of any desired size can be produced.The smallest form of a preferred embodiment of the hydrogen storage unit 50 forms a cube. This storage unit can hold 1 kg of H2. Its base area is 0.35×0.35 m 2. The height of the hydrogen storage unit 50 is 0.38 m. The height of the individual hydrogen storage cells is preferably 3.5 cm (0.035 m), so that the upper end plate and the lower end plate deviate slightly from the purely cubic shape.A larger, likewise preferred embodiment of the hydrogen storage unit 50 comprises a plurality of hydrogen storage cells 10. The tower 66 is formed by simply scaling up the number of hydrogen storage cells 10.A typical embodiment of a memory bank 68 is formed from a plurality of lined-up towns 66. In the embodiment shown here, 80 tower-shaped hydrogen storage units 50 are interconnected in the form of 8 x 10 Towns 66, which can form a storage bank 68 on a base surface of approximately 2.9 m x 3.6 m, which has a capacity of 400 kg H2. The upper connections for coolant 62 and gas connections 64 make possible a simple integration of the storage bank 68 into a cooling circuit. The cooling and thermal management may be external.Since the configuration of a storage bank 68 is effected by simply arranging the tower 66 of hydrogen storage units 50 one against the other, the installation area of the storage bank 68 can be adapted to the local space conditions in an uncomplicated manner. A further advantage of modularity is that in the event of a fault, individual tower 66 or hydrogen storage units 50 can be exchanged during ongoing operation.In practice, it has proven advantageous to adapt the necessary coolant flow through the individual hydrogen storage cells 10 to the charging and discharging rate of the hydrogen. Thus, it has been found within the scope of the invention that a flow rate of 0.022 liters / minute per hydrogen storage cell 10 is advantageous with a complete filling of 0 to 100% in 30 minutes. Cooling channels, connections, gas ports, inlets and outlets are to be dimensioned accordingly. The basis of the calculation is the reaction enthalpy of the metal hydride, the absorption (filling) at -18.5 kJ / mol H2and a reaction enthalpy of desorption (discharge) at 24 kJ / mol H2. In addition, passive cooling, which is dependent on the ambient temperature, can be carried out, which can be positively influenced by the material selection of the base bodies 12 of the hydrogen storage cells 10.The use of an aluminum alloy for the base body 12 has proven to be positive, so that the required cooling power can be further reduced by the suitable choice of material. The heat required for desorption can be introduced either by a connected heat exchanger or a heat pump. It is possible to couple the cooling circuit directly to the cooling circuit of a consumer. Such a coupling brings about an increase in the system efficiency, since with appropriate dimensioning no external energy is required for tempering the hydrogen storage and for cooling the consumer. The temperature control of the storage can be coupled to local heat sources and heat sinks, for example.Tower 66, shown in FIG. 6, suitable for storing 5 kg of H2has a volumetric storage density of 0.76 kWh / l. The preferred embodiment of hydrogen storage unit 50 in the form of tower 66 having dimensions of 0.35 m x 0.35 m x 1.8 m and a gravimetric energy density of hydrogen with Hi=33.33 kWh / kg has an energy content of 166.65 kWh in total. Thus, the hydrogen storage at the volumetric energy density is in the range of modern lithium ion storage devices, which have an energy density of approximately 0.5 kWh / l.The invention has been fully described and explained with reference to the drawings and the specification. The description and explanation are to be taken by way of example and not limitation. The invention is not limited to the disclosed embodiments. Other embodiments or variations will become apparent to those skilled in the art upon use of the present invention, as well as upon a detailed analysis of the drawings, disclosure and appended claims.In the claims, the words "comprise" and "with" do not exclude the presence of further elements or steps. The undefined article "a" or "an" does not exclude the presence of a plurality. A single element or unit may perform the functions of several of the units recited in the claims. The mere naming of some measures in several different dependent claims is not to be understood as meaning that a combination of these measures cannot likewise be used advantageously. Reference signs in the patent claims should be understood to be non-limiting.

Claims

A hydrogen storage cell for storing hydrogen in a metal hydride, comprising - a base body (12) having an upwardly open receiving space (14); - a cover layer (28) for closing the receiving space (14); - a metal hydride layer (16) in the receiving space (14); - a pressing element (18) with contact with the metal hydride layer (16), wherein the pressing element (18) exerts a force effect on the metal hydride layer (16); - a gas space (26) formed in the receiving space (14) for receiving hydrogen, wherein the gas space (26) is separated from the metal hydride layer (16) by the pressing element (18).Hydrogen storage cell according to Claim 1, characterized in that the base body (12) comprises aluminium, preferably an alloy of aluminium, particularly preferably Al Mg Si1.Hydrogen storage cell according to one of the preceding claims, characterized in that the base body (12) has a substantially rectangular base area, preferably a square base area, wherein the height of the base body (12) is at most 20% of the smaller side length of the base body (12), preferably at most 15%, further preferably at most 10%, particularly preferably at most 5%.Hydrogen storage cell according to one of the preceding claims, characterized in that the base body (12) has, on its underside (30), a cooling space (32) which is preferably designed as a cooling duct (34) and particularly preferably runs in meandering fashion.Hydrogen storage cell according to the preceding claim, characterized in that the cooling space (32) has a coolant inlet (36) and a coolant outlet (38) which are spaced apart from one another in such a way that incoming coolant flows through the cooling space (32) between the coolant inlet (36) and the coolant outlet (38), preferably to an extent of at least 80%, wherein preferably the coolant inlet (36) and coolant outlet (38) are arranged in the cooling space (32) at opposite endsHydrogen storage cell according to one of the preceding claims, characterized in that the pressing element (18) comprises a pressing plate (20) and / or a resilient element (22).Hydrogen storage cell according to one of the preceding claims, characterized in that a filter element is arranged in the receiving space (14) between the gas space (26) and the metal hydride layer (16) in order to at least reduce a transfer of material of the metal hydride layer (16) into the gas space (26), wherein the filter element is preferably integrated into the pressing element (18) and is further preferably formed by openings in the pressing element (18).Hydrogen storage cell according to the preceding claim, characterized in that the filter element comprises a metal fabric layer, a paper filter layer, a plastic filter layer or a combination of the said filter possibilities.Hydrogen storage cell according to one of the preceding claims, characterized in that the base body (12) has a gas port (40) for the supply and removal of the hydrogen, which gas port is connected to the gas space (26) of the receiving space (14), wherein the gas port (40) preferably comprises a filter, particularly preferably a filter made of sintered metal.Hydrogen storage cell according to one of the preceding claims, characterized in that the metal hydride is present in the metal hydride layer (16) in poured form, in pressed form or in the form of pellets.Hydrogen storage cell according to one of the preceding claims, characterized in that the hydrogen storage cell (10) is operated at pressures of at most 100 bar, preferably at most 50 bar, more preferably at most 30 bar, particularly preferably at most 20 bar.Hydrogen storage unit for storing gaseous hydrogen, having a plurality of hydrogen storage cells (10) which are fluidically interconnected in such a way that gas exchange is possible between the storage cells (10), wherein the storage cells (10) are stacked one above the other.Hydrogen storage unit according to the preceding claim, characterized in that the hydrogen storage cells (10) are formed according to one of the preceding claims.Hydrogen storage unit according to one of Claims 12 to 13, characterized in that the hydrogen storage unit (50) has an upper end plate (56) and a lower end plate (52), which can be a base (54), the upper end plate (56) having connections (62) for coolant and a gas connection (64) for hydrogen.Hydrogen storage unit according to one of Claims 12 to 14, characterized in that the base body (12) has a substantially square base area and the height of the base body (12) is dimensioned such that a hydrogen storage unit (50) having 10 hydrogen storage cells (10), an upper end plate (56) and a lower end plate (52) forms a cube.

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