HYDROGEN STORAGE DEVICE

Abstract

A hydrogen storage device (100A) comprises: a pressure vessel (230A), having a first fluid inlet (210A) and/or a first fluid outlet (220A), having therein a thermally conducting network (240A) optionally thermally coupled to a first heater and/or a first cooler; wherein the pressure vessel (230A) is arranged to receive therein a hydrogen storage material in thermal contact, at least in part, with the thermally conducting network (240A); wherein the thermally conducting network (240A) preferably has a lattice geometry, a gyroidal geometry and/or a fractal geometry in two and/or three dimensions, comprising a plurality of nodes, having thermally conducting arms therebetween, with voids between the arms; and wherein the thermally conducting network (240A) comprises fluidically interconnected passageways therein, for example within the arms and/or the nodes thereof, for flow therethough of a fluid.

Claims

1. A hydrogen storage device comprising: a pressure vessel, having a first fluid inlet and/or a first fluid outlet, having therein a thermally conducting network optionally thermally coupled to a first heater and/or a first cooler; wherein the pressure vessel is arranged to receive therein a hydrogen storage material in thermal contact, at least in part, with the thermally conducting network; wherein the thermally conducting network has a lattice geometry, a gyroidal geometry and/or a fractal geometry in two and/or three dimensions, comprising a plurality of nodes, having thermally conducting arms therebetween, with voids between the arms; and wherein the thermally conducting network comprises fluidically interconnected passageways therein for flow therethough of a fluid.

2. The hydrogen storage device according to claim 1, wherein the hydrogen storage device is arrangeable in: a first arrangement wherein the thermally conducting network is within the pressure vessel; and a second arrangement wherein the thermally conducting network is outside the pressure vessel.

3. The hydrogen storage device according to claim 1, wherein the hydrogen storage material comprises one or more selected from: a metal a hydride salt of a metal a borohydride salt of a metal borohydride salt of ammonium and/or alkyl ammonium; and mixtures thereof.

4. The hydrogen storage device according to claim 1, wherein the hydrogen storage material comprises and/or is an AB.sub.x alloy, wherein A is at least one selected from a group consisting of La, Ce, Pr, Nd, Ca, Y, Zr, and Mischmetal, wherein B is at least one selected from a group consisting of Ni, Co, Mn, Al, Cu, Fe, B, Sn, Si, Ti, and xis in a range from 4.5 to 5.5.

5. The hydrogen storage device according to claim 1, wherein the hydrogen storage material comprises and/or is an AB/A.sub.2B alloy, wherein A is at least one selected from a group consisting of Ti and Mg, and B is at least one selected from a group consisting of Ni, V, Cr, Zr, Mn, Co, Cu, and Fe.

6. The hydrogen storage device according to claim 1, wherein the hydrogen storage material comprises and/or is an AB.sub.2 alloy, wherein A is at least one selected from a group consisting of Ti, Zr, Hf, Th, Ce and rare earth metals, and B is at least one selected from a group consisting of Ni, Cr, Mn, V, Fe, Mn and Co.

7. The hydrogen storage device according to claim 1, wherein the hydrogen storage material comprises and/or is a metal hydride.

8. The hydrogen storage device according to claim 7, wherein the hydrogen storage material comprises one or more metal hydrides selected from a group consisting of: lithium hydride (LiH), sodium hydride (NaH), potassium hydride (KH), beryllium hydride (BeH.sub.2), magnesium hydride (MgH.sub.2), calcium hydride (CaH.sub.2), strontium hydride(SrH.sub.2), titanium hydride (TiH.sub.2), aluminum hydride (AlH.sub.3), boron hydride(BH.sub.3), lithium borohydride (LiBH.sub.4), sodium borohydride (NaBH.sub.4), magnesium borohydride (Mg(BH.sub.4).sub.2), calcium borohydride (Ca(BH.sub.4).sub.2), lithium alanate (LiAlH.sub.4), sodium alanate (NaAlH.sub.4), magnesium alanate (Mg(AlH.sub.4).sub.2), calcium alanate (Ca(AlH.sub.4).sub.2), and mixtures thereof.

9. The hydrogen storage device according to claim 7, wherein hydrogen storage material comprises and/or is one or more metal hydrides selected from MgH.sub.2, NaAlH.sub.4, LiAlH.sub.4, LiH, LaNi.sub.5H.sub.6, TiFeH.sub.2, palladium hydride PdH.sub.x, LiNH.sub.2, LiBH.sub.4 and NaBH.sub.4.

10. The hydrogen storage device according to claim 3, wherein the hydrogen storage material comprises an AB.sub.x alloy, an AB/A.sub.2B alloy, an AB.sub.2 alloy, a hydride and/or a mixture thereof.

11. The hydrogen storage device according to claim 1, wherein the hydrogen storage material comprises a dopant.

12. The hydrogen storage device according to claim 1, having a hydrogen storage density of at least 0.01 wt. % of the hydrogen storage vessel.

13. The hydrogen storage device according to claim 1, wherein the fractal geometry is selected from a group consistant of: Quadratic Koch Island, a Quadratic Koch surface, a Von Koch surface, a Koch Snowflake, a Sierpinski carpet, a Sierpinski tetrahedron, a Mandelbox, a Mandelbulb, a Dodecahedron fractal, a Icosahedron fractal, a Octahedron fractal, a Menger sponge, a Jerusalem cube, and a 3D H-fractal.

14. The hydrogen storage device according to claim 1, wherein an effective density of the lattice geometry is uniform in a first dimention and non-uniform in mutually orthogonal second and third dimensionsl.

15. The hydrogen storage device according to claim 1, wherein the lattice geometry is Bravais lattice a monoclinic; an orthorhombic; a tetragonal; a hexagonal; or a cubic lattic.

16. The hydrogen storage device according to claim 1, wherein the thermally conducting arms have a cross sectional dimension in a range from 0.1 mm to 10 mm and/or a length in range from 0.5 mm to 50 mm.

17. The hydrogen storage device according to claim 1, wherein the thermally conducting network is formed, at least in part, by additive manufacturing and/or by casting.

18. The hydrogen storage device according to claim 1, comprising a thermally-conducting foam.

19. The hydrogen storage device according to claim 1, wherein the thermally conducting network partially fills an internal volume of the pressure vessel, of at least 50% by volume of the pressure vessel, thereby defining an unfilled volume.

20. The hydrogen storage device according to claim 1, wherein the first heater comprises a Joule heater and/or a recirculating heater. cm 21-26. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0077] For a better understanding of the invention, and to show how exemplary embodiments of the same may be brought into effect, reference will be made, by way of example only, to the accompanying diagrammatic Figures, in which:

[0078] FIG. 1 is a CAD axial cross-section of a hydrogen storage device according to an exemplary embodiment;

[0079] FIG. 2 is a CAD axial cross-section of the hydrogen storage device of FIG. 1;

[0080] FIG. 3 schematically depicts a cutaway, perspective view of a simulation of the of the hydrogen storage device of FIG. 1;

[0081] FIG. 4A is a schematic axial cross-section of a hydrogen storage device according to an exemplary embodiment and FIGS. 4B to 4D are schematic transverse cross-sections of the hydrogen storage device of FIG. 4A;

[0082] FIGS. 5A to 5C schematically depict thermally conducting networks for a hydrogen storage device according to an exemplary embodiment;

[0083] FIG. 6A is a photograph of a foam for a hydrogen storage device according to an exemplary embodiment; and FIG. 6B is a schematic view of a hydrogen storage device according to an exemplary embodiment, in more detail;

[0084] FIG. 7A is a plan elevation view of a hydrogen storage device according to an exemplary embodiment; and FIG. 7B is a side cross-sectional view of the hydrogen storage device of FIG. 7A;

[0085] FIG. 8 is a CAD cutaway perspective view of a hydrogen storage device according to an exemplary embodiment;

[0086] FIG. 9 is a CAD axial cross-section of the hydrogen storage device of FIG. 10;

[0087] FIG. 10 is a CAD radial cross-section of the hydrogen storage device of FIG. 10;

[0088] FIG. 11 is an alternative CAD radial cross-section of the hydrogen storage device of FIG. 10;

[0089] FIG. 12 is a CAD cutaway perspective view of a hydrogen storage device according to an exemplary embodiment;

[0090] FIG. 13 is a CAD axial cross-section of the hydrogen storage device of FIG. 12;

[0091] FIG. 14 is a CAD radial cross-section of a thermally conducting network of the hydrogen storage device of FIG. 12;

[0092] FIG. 15 schematically depicts Bravais lattices for a thermally conducting network;

[0093] FIG. 16 is a CAD perspective view of a hydrogen storage device according to an exemplary embodiment;

[0094] FIG. 17 is a CAD axial cross-section of the hydrogen storage device of FIG. 16;

[0095] FIG. 18 is a CAD axial cross-section of a hydrogen storage device according to an exemplary embodiment;

[0096] FIG. 19 is a CAD perspective view of a charging station assembly according to an exemplary embodiment;

[0097] FIG. 20 shows the periodic table of elements, showing suitability of elements for hydrogen storage according to HHI Production, HHI Reserve and Abundance of the elements, where HHI is the Herfindahl-Hirschman index, a commonly accepted measure of market concentration, has been calculated from geological data (known elemental reserves) and geopolitical data (elemental production) for much of the periodic table;

[0098] FIG. 21 shows a chart of gravimetric H.sub.2 density (wt. %) as a function of volumetric H.sub.2 density (kg H.sub.2/m.sup.3) for metal hydrides, chemical hydrogen and absorbents;

[0099] FIG. 22 shows a chart of observed H.sub.2 capacity (wt. %) as a function of temperature, showing H.sub.2 sorption temperature (° C.) and temperature for observed H.sub.2 release (° C.), for metal hydrides, chemical hydrogen and absorbents;

[0100] FIG. 23A is a CAD perspective view of a hydrogen storage device according to an exemplary embodiment; FIG. 23B is a CAD perspective semi-transparent view of the hydrogen storage device of FIG. 23A; and FIG. 23C is a CAD axial cross-section view of the hydrogen storage device of FIG. 23A;

[0101] FIG. 24A is a cutaway perspective view of a hydrogen storage device according to an exemplary embodiment; and FIG. 24B is a cutaway perspective exploded view of a related hydrogen storage device;

[0102] FIG. 25 is a cutaway perspective view of a hydrogen storage device according to an exemplary embodiment;

[0103] FIG. 26A is a CAD partial cutaway perspective view of a hydrogen storage device according to an exemplary embodiment; FIG. 26B is a CAD longitudinal perspective cross-sectional view of the hydrogen storage device; and FIG. 26C is a CAD perspective view of the thermally conducting network, in more detail

[0104] FIG. 27A is a CAD partial cutaway perspective view of a hydrogen storage device according to an exemplary embodiment; and FIG. 27B is a CAD transverse cross-sectional view of the hydrogen storage device;

[0105] FIG. 28A is a CAD partial cutaway perspective view of a hydrogen storage device according to an exemplary embodiment; FIG. 28B is a CAD partial cutaway perspective view of the hydrogen storage device, in more detail; and FIG. 28C is a CAD exploded perspective view of a part of the hydrogen storage device, in more detail;

[0106] FIG. 29A is a CAD partial cutaway perspective view of a hydrogen storage device according to an exemplary embodiment; and FIG. 29B is a CAD longitudinal cross-sectional view of the hydrogen storage device;

[0107] FIG. 30 is a CAD partial cutaway exploded perspective view of a hydrogen storage device according to an exemplary embodiment;

[0108] FIG. 31 is a CAD transverse cross-sectional view of a hydrogen storage device according to an exemplary embodiment; and

[0109] FIG. 32 is a CAD partial cutaway perspective view of a hydrogen storage device according to an exemplary embodiment.

DETAILED DESCRIPTION OF THE DRAWINGS

[0110] FIG. 1 is a CAD axial cross-section of a hydrogen storage device 100A. FIG. 2 is a CAD axial cross-section of the hydrogen storage device 100A of FIG. 1. In this example, the hydrogen storage device 100A comprises: a pressure vessel 230A, having a first fluid inlet 210A and/or a first fluid outlet 220A, having therein a thermally conducting network 240A optionally thermally coupled to a first heater and/or a first cooler; wherein the pressure vessel 230A is arranged to receive therein a hydrogen storage material in thermal contact, at least in part, with the thermally conducting network 240A; wherein the thermally conducting network 240A preferably has a lattice geometry, a gyroidal geometry and/or a fractal geometry in two and/or three dimensions, comprising a plurality of nodes, having thermally conducting arms therebetween, with voids between the arms; and wherein the thermally conducting network 240A comprises fluidically interconnected passageways therein, for example within the arms and/or the nodes thereof, for flow therethough of a fluid.

[0111] In this example, the first hydrogen storage device 100A comprises a passageway 250A, wherein the first hydrogen storage device 200A is arrangeable in: a first configuration to receive a Joule heater in the passageway 250A; and a second configuration to receive a flow of a liquid through the passageway 250A. In the first configuration, a cartridge heater (not shown) is insertable into the passageway 250A through an end thereof and the opposed end of the passageway 250A is closed, with an insulating plug 260A. In the second configuration, the cartridge heater and the plug 260A are removed and fluid couplings 270A, 280A instead fitted to the ends, such that a recirculating liquid, such as coolant from a fuel cell, may be pumped therethrough.

[0112] In this example, the hydrogen storage device 100A is arranged to be oriented horizontally, in use. In this example, the pressure vessel 230A is generally cylindrical, having dished ends. In this example, the passageway, provided by a tube having a circular cross-section, extends between the dished ends longitudinally, offset from an axis of the pressure vessel 230A. In this example, the thermally conducting network 240A partially fills an internal volume of the pressure vessel 230A, particularly a region of the internal volume extending across about 75% of a diameter the pressure vessel, thereby completely surrounding the tube, such that an unfilled volume UV above the thermally conducting network 240A is defined. In this example, the thermally conducting network 240A is thermally coupled to at least a part of an internal surface of the pressure vessel 230A and an external surface of the tube. In this example, the unfilled volume UV acts as a buffer, providing a reservoir of hydrogen during charging and similarly during release, for example to account for kinetics thereof.

[0113] FIG. 3 schematically depicts a cutaway, perspective view of a simulation, particularly by finite element analysis (FEA) the hydrogen storage device of FIG. 1. In this example, the pressure vessel is generally cylindrical, having a wall thickness of 2 mm, and hemispherical dished ends, having a wall thickness of 1.5 mm. In this example, the pressure vessel is formed from a material having a yield stress at 100° C. of 181 MPa. In this example, a maximum stress at an operating pressure of 20 bar is 61 MPa, giving a safety factor of about 3. In this example, a maximum stress at an operating pressure of 5 bar is 15.2 MPa, giving a safety factor of about 11.9. Also shown is the deformed pressure vessel 230A′ and deformed passageway 240A′, following simulated yield.

[0114] FIG. 4A is a schematic axial cross-section of a hydrogen storage device 200 according to an exemplary embodiment and FIGS. 4B to 4D are schematic transverse cross-sections of the hydrogen storage device 200 of FIG. 4A.

[0115] FIGS. 4A-4D show the hydrogen storage device 200. The hydrogen storage device 200 comprises a hollow metal cylinder (outer cylindrical vessel wall (1)) and along with two metallic end-caps (2), providing the pressure vessel. Inside this volume exists the hydrideable metal/metal alloy (5), an aluminium fractal structure (4) with metallic foam in contact with it (not shown in figure). Both end-caps (2) contain an internal cavity for the location of multiple peltier devices (6) and heat/cold sinks (7). In the outer cylindrical vessel wall (1), there are three gas inlets (10) and three gas outlets (11) allow for heating/cooling gas (air) access to this internal cap cavity to add/remove heat. There is also an electronic entry/exit point (12) in the outer cylindrical vessel wall (1). In one of the end-caps four ports (holes) are included, allowing access into the pressure vessel; they are a hydrogen gas inlet (8), a hydrogen gas outlet (9), a pressure sensor connection (15) and a temperature sensor connection (14). The end-caps are held in place and form a seal through a thread and o-ring arrangement (3). The end-caps can be removed for easy access to the pressure vessel. The end-caps have covers (13) which can be removed for easy access to the heating/cooling gas containment volume within them.

[0116] In this example, the hydrogen storage device 200 comprises: a pressure vessel 1, having a first fluid inlet 8 and/or a first fluid outlet 9, having therein a thermally conducting network 4 optionally thermally coupled to a first heater and/or a first cooler; wherein the pressure vessel 1 is arranged to receive therein a hydrogen storage material in thermal contact, at least in part, with the thermally conducting network 4; wherein the thermally conducting network 340 has a fractal geometry in two dimensions, comprising a plurality of nodes, having thermally conducting arms therebetween, with voids between the arms; and wherein the thermally conducting network 4 comprises fluidically interconnected passageways therein, within the arms and the nodes thereof, for flow therethough of a fluid.

[0117] FIGS. 5A to 5C schematically depict thermally conducting networks for a hydrogen storage device according to an exemplary embodiment.

[0118] FIG. 5 shows there are shown three alternative fractal networks (A) Gosper Island; (B) ‘Snowflake’ design; and (C) Koch Snowflake for the thermally conducting network of the hydrogen storage device 200. The 2D radially symmetric fractal patterns extend axially. Axial cross-sections, midpoint radial cross-sections and perspective views for the fractal networks are shown.

[0119] FIG. 6A is a photograph of a foam for a hydrogen storage device according to an exemplary embodiment; and FIG. 6B is a schematic view of a hydrogen storage device according to an exemplary embodiment, in more detail.

[0120] FIG. 6A shows a photograph of voids (i.e. open space) in a metal foam, particularly aluminium foam. The aluminium foam is produced from 6101 aluminium alloy, retaining 99% purity of the parent alloy. The foam has a reticulated structure in which cells (i.e. pores) are open and have a dodecahedral shape. The foam has a bulk density of 0.2 g/cm3; a porosity of 93% porosity and about 8 pores/cm.

[0121] FIG. 6B schematically depicts a metal hydride powder included and/or in contact with a metal foam which in turn is thermally coupled to a thermally conducting network.

[0122] FIG. 7A is a plan elevation view of a hydrogen storage device 200′ according to an exemplary embodiment and FIG. 7B is a side cross-sectional view of the hydrogen storage device 200′ of FIG. 7A.

[0123] FIGS. 7A and 7B schematically depict a compact design of a hydrogen storage device 200′. The hydrogen storage device 200′ comprises a hydrogen gas containment volume formed from a cuboid-based container vessel (1) with square-planar lid (2). The lid (2) is secured through the use of four axial-corner screws in screw fixings (7) and it is sealed by an 0-ring (3) positioned between the vessel (1) and the lid (2). The hydrogen containment volume has within it a hydrideable metal/metal alloy (5) and metal foam (not shown). On one surface there is a thermally conducting network (4) having a flat square-based fractal geometry, that acts to dissipate heat radially. A Peltier device (6), thermally coupled to the thermally conducting network (4) and outside of the vessel (1) acts as a heater/cooler. Two holes (8) and (9) located through the lid (2) and the thermally conducting network (4) act as a hydrogen gas inlet (8) and outlet (9), respectively. That is, the hydrogen storage device 200′ comprises the pressure vessel 1, having the first fluid inlet 8 and the first fluid outlet 9, comprising therein a thermally conducting network 4 optionally thermally coupled to the first heater (not shown), wherein the pressure vessel 1 is arranged to receive therein a hydrogen storage material (not shown) in thermal contact, at least in part, with the thermally conducting network 4, wherein the first fluid inlet 8 and/or the first fluid outlet 9 are in fluid communication with the first releasable fluid inlet coupling (not shown) and/or the first releasable fluid outlet coupling (not shown), respectively; and preferably, wherein the thermally conducting network 4 has a lattice geometry and/or a fractal geometry in two and/or three dimensions.

[0124] FIG. 8 is CAD cutaway perspective view of a hydrogen storage device 200″ according to an exemplary embodiment. FIG. 9 is CAD axial cross-section of the hydrogen storage device 200″of FIG. 8. FIG. 10 is a CAD radial cross-section of the hydrogen storage device 200″of FIG. 8.

[0125] In this example, the hydrogen storage device 200″ comprises: a pressure vessel 201″, having a first fluid inlet 208″ and/or a first fluid outlet 209″, having therein a thermally conducting network 204″ optionally thermally coupled to a first heater and/or a first cooler;

[0126] wherein the pressure vessel 201″ is arranged to receive therein a hydrogen storage material in thermal contact, at least in part, with the thermally conducting network 204″; wherein the thermally conducting network 203″ has a fractal geometry in two dimensions, comprising a plurality of nodes, having thermally conducting arms therebetween, with voids between the arms; and wherein the thermally conducting network 204″ comprises fluidically interconnected passageways therein, within the arms and the nodes thereof, for flow therethough of a fluid.

[0127] In this example, the pressure vessel 201″ is generally cylindrical, having a generally dished first end and a necked second end opposed thereto, and having a single aperture providing both the first fluid inlet 208″ and the first fluid outlet 209″. In other words, the pressure vessel 201″ is bottle-shaped. An inner wall portion 2011″ of the pressure vessel 201″ provides an axial cylindrical, elongate blind passageway 210″, arranged to receive a first heater 206″ (not shown), that extends from the first end towards the second end and that is coaxial with an outer wall portion 2010″ of the pressure vessel 201″. A second blind passageway in the first end is arranged to receive a thermocouple (not shown).

[0128] In this example, the pressure vessel has an internal volume of about 500 cm.sup.3, thereby providing a hydrogen storage capacity of about 25 g Hz. In this example, .

[0129] In this example, the thermally conducting network 204″ has a lattice geometry in three dimensions. In this example, an effective density of the lattice geometry is uniform in a first dimension, particularly axially, and non-uniform in mutually orthogonal second and third dimensions, particularly radially. Particularly, the effective density decreases radially outwards, such that there is faster heat transfer proximal the passageway 210″ and hence the first heater. In this example, the thermally conducting network 204″ is formed from an aluminium alloy. Alternatively, the thermally conducting network 204″ may be formed from copper, respective alloys thereof such as brass or bronze alloys, and/or stainless steel, as described previously.

[0130] FIG. 11 is an alternative CAD radial cross-section for the hydrogen storage device 200″ of FIG. 10. In this example, a node density (i.e. number of nodes per unit volume) of the lattice geometry, generally otherwise similar to the lattice geometry of FIG. 10 mutatis mutandis, is relatively lower than that of the lattice geometry of FIG. 10. A cross-sectional area of the arms is relatively larger than that of FIG. 10.

[0131] FIG. 12 is a CAD cutaway perspective view of a hydrogen storage device 200′″ according to an exemplary embodiment. FIG. 13 is a CAD axial cross-section of the hydrogen storage device 200′″ of FIG. 12. In this example, the pressure vessel 201′″ has an internal volume of about 50 cm.sup.3, thereby providing a hydrogen storage capacity of about 2.5 g H.sub.2.

[0132] FIG. 14 is a CAD radial cross-section of a thermally conducting network of the hydrogen storage device of FIG. 12. Generally, the lattice geometry is as described with respect to FIG. 11.

[0133] FIG. 15 schematically depicts Bravais lattices for a thermally conducting network, as described above.

[0134] FIG. 16 is a CAD perspective view of a hydrogen storage device 200B according to an exemplary embodiment, generally as described with respect to the hydrogen storage device 200A. FIG. 17 is a CAD axial cross-section of the hydrogen storage device 200B of FIG. 16. In this example, the hydrogen storage device 200B is arranged to be oriented horizontally, in use. In this example, the pressure vessel 230B is generally cylindrical, having dished ends. In this example, a passageway 250B, provided by a tube having a circular cross-section, extends between the dished ends longitudinally, offset from an axis of the pressure vessel 230A. In this example, the thermally conducting network 240B partially fills an internal volume of the pressure vessel, particularly a region of the internal volume extending across about 75% of a diameter the pressure vessel, thereby completely surrounding the tube, such that an unfilled volume above the thermally conducting network 240B is defined. In this example, the thermally conducting network 240B is thermally coupled to at least a part of an internal surface of the pressure vessel 230B and an external surface of the tube. In this example, the unfilled volume acts as a buffer, providing a reservoir of hydrogen during charging and similarly during release, for example to account for kinetics thereof.

[0135] FIG. 18 is a CAD axial cross-section of a hydrogen storage device 240C according to an exemplary embodiment, generally as described with respect to FIGS. 16 and 17, having a relatively longer axial length and a relatively smaller diameter.

[0136] FIG. 19 is a CAD perspective view of a charging station assembly 1 according to an exemplary embodiment. The charging station assembly 1 comprises a charging station 2 and a hydrogen storage device 200. In this example, the charging station 2 is arranged to receive eight hydrogen storage devices, arranged in a bank of 4×2 hydrogen storage devices. In this example, the charging station 2 is arranged to charge a plurality of hydrogen storage devices 200, for example simultaneously. In this example, the charging station 2 comprises a manifold 3 coupleable to the plurality of hydrogen storage devices 200. In this example, the charging station 2 comprises a cooling system 4, arranged to cool a hydrogen storage device during charging thereof. In this example, the cooling system 2 comprises a plurality of fans.

[0137] FIG. 23A is a CAD perspective view of a hydrogen storage device 300 according to an exemplary embodiment; FIG. 23B is a CAD perspective semi-transparent view of the hydrogen storage device 300 of FIG. 23A; and FIG. 23C is a CAD axial cross-section view of the hydrogen storage device 300 of FIG. 23A.

[0138] In this example, the hydrogen storage device 300 comprises: a pressure vessel 330, having a first fluid inlet 310 and/or a first fluid outlet 320, having therein a thermally conducting network 340 optionally thermally coupled to a first heater and/or a first cooler; wherein the pressure vessel 330 is arranged to receive therein a hydrogen storage material in thermal contact, at least in part, with the thermally conducting network 340; wherein the thermally conducting network 340 has a fractal geometry in two dimensions, comprising a plurality of nodes 341, having thermally conducting arms 342 therebetween, with voids V between the arms 342; and wherein the thermally conducting network 340 comprises fluidically interconnected passageways 343 therein, within the arms 342 and the nodes 341 thereof, for flow therethough of a fluid.

[0139] The hydrogen storage device 300 is generally as described with respect to the hydrogen storage device 100A of FIG. 1.

[0140] FIG. 24A is a cutaway perspective view of a hydrogen storage device 200 according to an exemplary embodiment. The hydrogen storage device 200 comprises a pressure vessel 230, having a first fluid inlet 210 and a first fluid outlet 220, comprising therein a thermally conducting network 240 thermally coupled to a first heater 300A, wherein the pressure vessel 230 is arranged to receive therein a hydrogen storage material (not shown) in thermal contact, at least in part, with the thermally conducting network 240, wherein the first fluid inlet 210 and/or the first fluid outlet 220 are in fluid communication with the first releasable fluid inlet coupling (not shown) and/or the first releasable fluid outlet coupling (not shown), respectively;

[0141] and wherein the thermally conducting network 240 has a lattice geometry in three dimensions.

[0142] In this example, the pressure vessel 230 is generally cylindrical, having a generally internally dished first end and a flanged second end opposed thereto, and having a single aperture providing both the first fluid inlet 210 and the first fluid outlet 220. In other words, the pressure vessel 230 is can-shaped. An inner wall portion 2301 of the pressure vessel 230 provides an axial cylindrical, elongate blind passageway P, arranged to optionally receive a second heater 300B (not shown) of the set of heaters 300, particularly a cartridge heater (not shown), that extends from the first end towards the second end and that is coaxial with an outer wall portion 2300 of the pressure vessel 230. Blind passageways in the second end are arranged to receive thermocouples TC. In this example, the first heater 300A is provided by a recirculating heater, for example heated using waste heat from a fuel cell coupled thereto, and includes a double helix heating tube 350, having an inlet 310 and an outlet 320, in thermal contact with the thermally conducting network 240, which is arranged between the inner 3501 and outer 3500 helices of the heating tube 350. The double helix heating tube 350 extends from the second end towards the first end is coaxial with an outer wall portion 2300 of the pressure vessel 230. The inner 3501 and outer 3500 helices of the double helix heating tube 350 are directly in thermal contact with the inner wall portion 2301 and the outer wall portion 2300 of the pressure vessel 230, respectively. A pressure gauge PG is provided in the second end. The second end is mechanically releasably coupled to the pressure vessel 230, using mechanical fasteners.

[0143] In this example, the thermally conducting network 240 has a lattice geometry in three dimensions, in which generally each node is connected by four arms to four other nodes, respectively, in an axially adjacent preceding layer, such that generally each node is thus connected by eight arms to eight other nodes, four nodes in the axially adjacent preceding layer and four nodes in an axially adjacent proceeding layer. Nodes proximal the inner 3501 and outer 3500 helices of the heating tube 350 are in mutual thermal contact therewith. In this example, an effective density of the lattice geometry is uniform in a first dimension, particularly axially, and non-uniform in mutually orthogonal second and third dimensions, particularly radially. In this example, the thermally conducting network 240 has a porosity of at least 90%. In this example, the thermally conducting network 240 is formed from an aluminium alloy. In this example, the thermally conducting network 240 comprises inner 2401 and outer 2400 portions, having annular shapes. The outer portion 2400 is received in thermal contact with and between the inner 3501 and outer 3500 helices of the double helix heating tube 350 while the inner portion 2401 is received in thermal contact with and within the inner helix 3501.

[0144] FIG. 24B is a cutaway perspective exploded view of a related hydrogen storage device 200. In contrast with the hydrogen storage device 200 of FIG. 24A, the thermally conducting network 240 of the hydrogen storage device 200 of FIG. 24B comprises inner 2401, middle 240M and outer 2400 portions. The inner portion 2401 has a cylindrical shape and the middle 240M and outer 2400 portions have annular shapes. The outer portion 2400 is received in thermal contact and without the outer 3500 helices of the double helix heating tube 350, the middle portion 240M is received in thermal contact with and between the inner 3501 and outer 3500 helices while the inner portion 2401 is received in thermal contact with and within the inner helix 3501.

[0145] FIG. 25 is a cutaway perspective view of a hydrogen storage device according to an exemplary embodiment. The hydrogen storage device 200 is generally as described with respect to the hydrogen storage devices 200 of FIGS. 24A and 24B and like reference signs denote like features.

[0146] In contrast with the hydrogen storage device 200 of FIGS. 24A and 24B, the hydrogen storage device 200 does not include the inner wall portion 2301 of the pressure vessel 230 of FIGS. 24A and 24B and does not include blind passageways in the second end to receive thermocouples. In contrast with the hydrogen storage device 200 of FIGS. 24A and 24B, the thermally conducting network 240 is cylindrical, to be received in thermal contact with the outer wall portion 2300 of the pressure vessel 230. In contrast with the hydrogen storage device 200 of FIGS. 24A and 24B, the inner 3501 and outer 3500 helices of the double helix heating tube 350 are integrated within the thermally conducting network 240. Hence, the inner 3501 and outer 3500 helices of the double helix heating tube 350 are mutually spaced apart from and only indirectly in thermal contact with the outer wall portion 2300 of the pressure vessel 230, respectively, via the thermally conducting network 240. In this example, the hydrogen storage device 200 includes a bed compression disc 231, internal to the pressure vessel 230 proximal the first end and bed compression disc bolts 232 mechanically coupled thereto, extending through the first end, for uniaxially compressing the hydrogen storage material to improve thermal contact with the thermally conducting network. 0-rings 233 are arranged in the outer wall portion 2300 to prevent loss of the hydrogen storage material during compression thereof.

[0147] FIG. 26A is a CAD partial cutaway perspective view of a hydrogen storage device 200 according to an exemplary embodiment; FIG. 26B is a CAD longitudinal perspective cross-sectional view of the hydrogen storage device 200; and FIG. 26C is a CAD perspective view of the thermally conducting network, in more detail.

[0148] The hydrogen storage device 200 comprises a pressure vessel 230, having a first fluid inlet 210 and a first fluid outlet 220, comprising therein a thermally conducting network 240 thermally coupled to a first heater 300A, wherein the pressure vessel 230 is arranged to receive therein a hydrogen storage material (not shown) in thermal contact, at least in part, with the thermally conducting network 240, wherein the first fluid inlet 210 and/or the first fluid outlet 220 are in fluid communication with the first releasable fluid inlet coupling (not shown) and/or the first releasable fluid outlet coupling (not shown), respectively; and wherein the thermally conducting network 240 has a lattice geometry in three dimensions. In this example, the hydrogen storage material comprises and/or is a liquid organic hydrogen carrier, LOHC. In this example, the hydrogen storage device 200 is a dynamic hydrogen storage device 200. In this example, the first fluid inlet 210 and the first fluid outlet 220 are mutually spaced apart at opposed ends of the first vessel 230, thereby defining, at least in part, a path for flow of the hydrogen storage material and/or hydrogen therebetween, for example via the voids of the thermally conducting network 240. In this example, the first fluid inlet 210 and the first fluid outlet 220 comprise releasable couplings, thereby providing coupling thereto and uncoupling therefrom, for example repeatedly, of corresponding couplings. In this example, the lattice geometry is Bravais lattice particularly a cubic lattice specifically a primitive cubic lattice. In this example, the thermally conducting arms have a cross sectional dimension (for example a diameter or a width) of about 0.5 mm. In this example, the thermally conducting network 240 partially fills an internal volume of the first vessel 230, of at least 90%, by volume of the first vessel 230. In this example, the thermally conducting network 240 comprises a LOHC hydrogenation and/or dehydrogenation catalyst, for example provided on and/or in a surface thereof. In this example, the thermally conducting network 240 has a porosity in a range from 75% to 95%, by volume of the thermally conducting network 240. In this example, the thermally conducting network 240 has a specific surface area in a range from 1 m.sup.−1 to 10 m.sup.−1, particularly about 7 m.sup.−1. In this example, the thermally conducting network 240 comprises a LOHC hydrogenation and/or dehydrogenation catalyst, for example provided on and/or in a surface thereof. In this example, the first heater is arranged heat the hydrogen storage material to temperature in a range from 150° C. to 300° C. In this example, the hydrogen storage device 200 comprises a pump (not shown) arranged to flow the hydrogen storage material through the first vessel 230. In this example, the hydrogen storage device 200 is a reactor.

[0149] Generally, the first vessel 230 is an elongated cylinder formed from a Ti alloy (to withstand an operating pressure of about 2 bar at a temperature of about 260° C. for dehydrogenation), having a bore extending therethrough for the first heater, particularly a Joule cartridge heater. The first fluid inlet 210 and the first fluid outlet 220 are provided with Swagelok releasable couplings. The first fluid inlet 210 is arranged at an acute angle to the axis of the first vessel and the first fluid outlet is arranged parallel to the axis, to suit the particular application.

[0150] FIG. 27A is a CAD partial cutaway perspective view of a hydrogen storage device 300 according to an exemplary embodiment; and FIG. 27B is a CAD transverse cross-sectional view of the hydrogen storage device 300. The hydrogen storage device 300 is generally as described with respect to the hydrogen storage device 200 of FIGS. 24A and 24B. Like reference signs denote like features. In this example, the thermally conducting network 240 is provided by four extrusions 240A to 240D, for example of aluminium or copper or an alloy thereof (i.e. having a relatively high thermal conductivity), each disposed in a quadrant of the pressure vessel 230 and extending between opposed faces thereof, thereby maximising a length of the pressure vessel 230 benefiting from the thermally conducting network 240. The four extrusions 240A to 240D each comprise 22 planar fins 241 radiating from four heating tubes 350A to 350D, as described below. Ends of the fins of an extrusion are in thermal contact with corresponding fins of an adjacent extrusion or the wall of the pressure vessel 230. Voids between the fins may be filled with a hydrogen storage material. A thermally conducting network having a fractal geometry in two dimensions may similarly be provided by extrusion. In this way, the thermally conducting network 240 may be provided cost effectively, by extrusion. In this example, the first heater 300A is provided by a recirculating heater, for example heated using waste heat from a fuel cell coupled thereto, and includes four heating tubes 350A to 350D, having inlets 310A to 310D and outlets 320A to 320D (not shown) respectively, in thermal contact with the thermally conducting network 240 and extending between opposed faces of the pressure vessel 230.

[0151] FIG. 28A is a CAD partial cutaway perspective view of a hydrogen storage device 400 according to an exemplary embodiment; FIG. 28B is a CAD partial cutaway perspective view of the hydrogen storage device 400, in more detail; and FIG. 28C is a CAD exploded perspective view of a part of the hydrogen storage device 400, in more detail. The hydrogen storage device 400 is generally as described with respect to the hydrogen storage device 300 of FIGS. 27A to 27B. Like reference signs denote like features. In this example, the four extrusions 240A to 240D extend from one face of the pressure vessel 230 towards the opposed face, with a headspace H disposed thereabove proximal the opposed face for storage of hydrogen, as a buffer. In this way, hydrogen may be stored in the headspace H at a relatively low pressure, for example for start up. The headspace is delimited by a plate assembly 290, comprising a first plate 291, a second plate 292 and a gasket 293 and a mesh 294 therebetween. A central aperture A, covered by the mesh 294, allows hydrogen to flow therethrough while the mesh 294 retains the hydrogen storage material therebelow.

[0152] FIG. 29A is a CAD partial cutaway perspective view of a hydrogen storage device 500 according to an exemplary embodiment; and FIG. 29B is a CAD longitudinal cross-sectional view of the hydrogen storage device 500. The hydrogen storage device 500 is generally as described with respect to the hydrogen storage device 400 of FIGS. 28A to 28C. Like reference signs denote like features. In this example, the four extrusions 240A to 240D are spaced apart from both faces of the pressure vessel 230. In this example, the hydrogen storage device 400 includes two U-shaped heating tubes 350A to 350B, having inlets 310A to 310B and outlets 320A to 320B respectively, in thermal contact with the thermally conducting network 240 and projecting from one face towards the opposed face of the pressure vessel 230. By reducing the number of preparations in the pressure vessel 230, potential leakage points are avoided while standard off-the-shelf components may be used. However, the thermally conducting network 240 is relatively shorter.

[0153] FIG. 30 is a CAD partial cutaway exploded perspective view of a hydrogen storage device 600 according to an exemplary embodiment. The hydrogen storage device 600 is generally as described with respect to the hydrogen storage device 400 of FIGS. 28A to 28C.

[0154] Like reference signs denote like features. In this example, the thermally conducting network 240 comprises metal foam quadrants or wedges, for example manufactured by rolling a sheet of foam around a tubular core and subsequently, dividing the rolled foam cylinder. Thermal contact with the walls of the pressure vessel 230 arises from compression of the foam thereagainst.

[0155] FIG. 31 is a CAD transverse cross-sectional view of a hydrogen storage device 700 according to an exemplary embodiment. In this example, a hybrid thermally conducting network 240 is provided by an extrusion, as described with respect to FIGS. 27A and 27B, having foam, generally as described with respect to FIG. 31, arranged between the fins.

[0156] FIG. 32 is a CAD partial cutaway perspective view of a hydrogen storage device 800 according to an exemplary embodiment. The hydrogen storage device 800 is generally as described with respect to the hydrogen storage device 200 of FIGS. 24A and 24B. Like reference signs denote like features. In this example, the thermally conducting network 240 comprises an aluminium foam having a porosity of 93%. Alternatives

[0157] Although a preferred embodiment has been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims and as described above.

Summary

[0158] In summary, the invention provides a hydrogen storage device comprising: a pressure vessel, having a first fluid inlet and/or a first fluid outlet, having therein a thermally conducting network optionally thermally coupled to a first heater and/or a first cooler; wherein the pressure vessel is arranged to receive therein a hydrogen storage material in thermal contact, at least in part, with the thermally conducting network; wherein the thermally conducting network preferably has a lattice geometry, a gyroidal geometry and/or a fractal geometry in two and/or three dimensions, comprising a plurality of nodes, having thermally conducting arms therebetween, with voids between the arms; and wherein the thermally conducting network comprises fluidically interconnected passageways therein, for example within the arms and/or the nodes thereof, for flow therethough of a fluid.

[0159] In this way, control for charging and/or release of hydrogen from the hydrogen storage device is improved because the flow of the fluid through the interconnected passageways in the thermally conducting network provides for faster, more homogenous, more accurate and/or more precise heating and/or cooling of the thermally conducting network and in turn, the hydrogen storage material in thermal contact therewith. Additionally and/or alternatively, in this way, storing and/or release of the hydrogen may be accelerated since heat generated or required, respectively, may be provided by the flow of the fluid through the interconnected passageways in the thermally conducting network. Disclosure

[0160] Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

[0161] All of the features disclosed in this specification (including any accompanying claims and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at most some of such features and/or steps are mutually exclusive.

[0162] Each feature disclosed in this specification (including any accompanying claims, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[0163] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.