HK1122545B

HK1122545B - Composite hydrogen storage material and methods related thereto

Info

Publication number: HK1122545B
Application number: HK08113636.5A
Authority: HK
Inventors: Joerg Zimmermann
Original assignee: Intelligent Energy Limited
Priority date: 2005-04-22
Filing date: 2006-04-24
Publication date: 2011-09-09

Description

Composite hydrogen storage materials and methods related thereto

Priority of invention

This non-provisional application is in accordance with clause 119(e) of U.S. 35, claiming priority from U.S. provisional patent application 60/673,859 filed on 22.4.2005, which is incorporated herein by reference.

Technical Field

Embodiments of the present invention relate to a composite hydrogen storage material. In particular, embodiments of the present invention relate to a composite hydrogen storage material for occluding and desorbing hydrogen.

Background

Typically, hydrogen can be stored in the form of metal hydride powders. During the hydrogenation/dehydrogenation cycle, the strain behavior destabilizes the particulate bed, resulting in settling and compaction of the particulate bed. Due to repeated cycling, the three-dimensional spatial relationship of the powdered particles is constantly changing, causing the strain to constantly increase. When metal hydride powders are used, inefficient heat transfer can hinder the rate and efficiency of the hydrogenation/dehydrogenation cycle.

Safety and handling issues arise when using conventional metal hydride powders because many materials are pyrophoric, or become pyrophoric upon contact with hydrogen. Furthermore, the powder may be blown into the hydrogen stream, which would require complicated filtering and introduce a pressure drop in the fuel system.

During hydrogenation/dehydrogenation, strain is created on the storage medium causing it to expand when injected and contract when released. This strain can be very large and is often addressed by designing a hydride storage container with an expansion space that can accommodate the strain. However, the instability of the particle bed causes compaction of the hydride material, rapid filling of the expansion space and significant strain to be imposed on the walls of the storage vessel. Therefore, the storage vessel must be designed to address this internally generated mechanical strain by increasing the wall thickness or developing a system of internal structures that allow the bed to self decompress as the strain is generated. These complex designs required for the storage vessel significantly reduce the hydrogen storage bulk density of the metal hydride powder.

The hydrogenation/dehydrogenation process causes the powder particles to pack more tightly, thus increasing the compactness of the system. During the hydrogenation/dehydrogenation cycle, the three-dimensional spatial relationship of the particles changes, adversely affecting the hydrogen storage capacity of the powder.

Drawings

The drawings are not necessarily to scale, and like reference numerals designate substantially similar components throughout the several views. Like numerals having different letter suffixes represent different instances of substantially similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed herein.

Fig. 1 illustrates a block flow diagram of a method of making a composite hydrogen storage material in some embodiments of the invention.

Fig. 2 illustrates a block flow diagram of a method for occluding and desorbing hydrogen using a composite hydrogen storage material in some embodiments of the invention.

Fig. 3 illustrates a graph of pressure-composition-temperature (PCT) during a hydrogenation/dehydrogenation cycle for an exemplary metal hydride hydrogen storage material that can be used in some embodiments of the invention.

Fig. 4 illustrates a perspective view of a storage vessel using a composite hydrogen storage material in communication with an apparatus, according to some embodiments of the invention.

Fig. 5 illustrates a perspective view of a storage vessel using a composite hydrogen storage material in some embodiments of the invention.

Fig. 6 illustrates a cross-sectional view of a storage vessel using a composite hydrogen storage material disposed on an interior wall of the vessel in some embodiments of the invention.

Fig. 7 illustrates a cross-sectional view of a storage vessel using a composite hydrogen storage material as a matrix that substantially fills the storage vessel in some embodiments of the invention.

Fig. 8 illustrates a cross-sectional view of a storage vessel using a composite hydrogen storage material as a multi-layered matrix in the storage vessel in some embodiments of the invention.

Fig. 9 illustrates a perspective view of a composite hydrogen storage material structure in some embodiments of the invention.

Disclosure of Invention

Embodiments of the present invention relate to a composite hydrogen storage material comprising active material particles and a binder, wherein the binder immobilizes the active material particles sufficient to maintain relative spatial relationships between the active material particles. Further, embodiments are directed to a hydrogen storage system comprising a storage vessel, a composite hydrogen storage material disposed within the storage vessel, wherein the composite hydrogen storage material comprises active material particles and a binder, wherein the binder immobilizes the active material particles sufficient to maintain relative spatial relationships between the active material particles, and at least one port for communication with an external device.

Embodiments of the present invention relate to a method of making a composite hydrogen storage material, comprising: forming a fine powder of active material particles, mixing a binder with the fine powder to form a mixture and heating the mixture sufficiently to form a composite hydrogen storage material, wherein the binder immobilizes the active material particles sufficient to maintain relative spatial relationships between the active material particles. Embodiments of the present invention also relate to a method of using a composite hydrogen storage material comprising occluding hydrogen on or in the composite hydrogen storage material and desorbing hydrogen from the composite hydrogen storage material, wherein the composite hydrogen storage material comprises active material particles and a binder, wherein the binder immobilizes the active material particles sufficient to maintain a relative spatial relationship between the active material particles.

Detailed Description

The following detailed description includes references to the accompanying drawings, which form a part hereof. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments (also referred to herein as "examples") are described in sufficient detail to enable those skilled in the art to practice the invention. These embodiments may be combined, other embodiments may be utilized, or structural or logical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents.

As used herein, the terms "a" or "an" encompass one or more, and the terms "or" are used to mean non-exclusive or unless otherwise indicated. Also, it is to be understood that the phraseology and terminology employed herein, and not otherwise defined, are for the purpose of description and should not be regarded as limiting. In addition, all publications, patents and patent documents referred to herein are incorporated by reference in their entirety as if individually incorporated by reference. The use in the documents incorporated by reference should be understood to be complementary to the use in the present specification if there is an inconsistent use between the present specification and the documents incorporated by reference; in case of conflict, the present specification, including definitions, will control.

Embodiments of the present invention provide a composite hydrogen storage material and methods related thereto. The composite hydrogen storage material allows for the reduction or elimination of particle bed compaction caused by decrepitation (decrepitation) conventionally in hydrogenation/dehydrogenation cycles during hydrogen occlusion and desorption. The composite hydrogen storage material includes active material particles and a binder, wherein the binder immobilizes the active material particles sufficient to maintain relative spatial relationships between the active material particles. The composite hydrogen storage material may deform upon hydrogenation but substantially revert to its original shape and morphology, and thus, the three-dimensional spatial relationship between the active material particles is substantially unchanged during multiple hydrogenation/dehydrogenation cycles.

The composite hydrogen storage material may also serve as a load bearing member in the storage vessel, effectively increasing the volumetric energy storage capacity of the vessel. By utilizing the composite hydrogen storage material of embodiments of the present invention, the need for filtration of loose metal hydride particles in the desorbed hydrogen stream is eliminated, and the conventional problem of powder compaction in metal hydride storage vessels is eliminated. The composite hydrogen storage material has better thermal conductivity than conventional metal hydride powders, and retains similar adsorption/desorption rates and capacity limits. The use of composite hydrogen storage materials for the storage of hydrogen is safer than conventional metal hydride powders because the risk of rupture of the storage vessel due to powder compaction is much less. In addition, the use of the composite hydrogen storage material for the storage of hydrogen better complies with national and international regulatory laws and procedures regarding the transport of hydrogen and hydrogen storage vessels.

Definition of

As used herein, "composite hydrogen storage material" refers to active material particles mixed with a binder, wherein the binder immobilizes the active material particles sufficient to maintain relative spatial relationships between the active material particles.

As used herein, "relative spatial relationship" refers to the three-dimensional spatial relationship between particles. This three-dimensional spatial relationship between the particles as described in the context of the present invention remains substantially unchanged. For example, the distance between particles may vary during a hydrogenation/dehydrogenation cycle, but the particles return to substantially the same position relative to other particles over the course of one complete cycle. The structure of the particles may have, for example, elasticity, in which the particles are movable, but they maintain substantially the same three-dimensional spatial position relative to other particles when moved. One exemplary indication of whether a material meets the above characteristics is a qualitative measurement of, for example, the volume, packing density, or porosity or size (e.g., length) of the composite material that has undergone repeated cycles. Thus, when the length of the formed composite is used as an indicator parameter, the length of the formed composite should be at least about 80% and not more than about 120% of the original length measured.

The verb or noun form of "occlusion" as used herein refers to the absorption or adsorption and retention of a substance. For example, the occluded substance may be hydrogen. A substance may be occluded chemically or physically, for example by chemisorption or physisorption.

The verb or noun form of "desorption" as used herein refers to the removal of an absorbed or adsorbed substance. For example, hydrogen may be removed from the active material particles. For example, hydrogen may be bound physically or chemically.

As used herein, "render. For example, the active material particles may be immobilized, allowing them to move, but maintaining the particles in substantially the same geometric relationship with each other over multiple hydrogenation/dehydrogenation cycles.

As used herein, "metal hydride particles" or "metal hydrides" refer to metal particles or metal alloy particles that are capable of generating metal hydrides when exposed to hydrogen. An example of such a metal or metal alloy is LaNi₅、FeTi、Mg₂Ni and ZrV₂. These compounds are representative examples of metal hydride compounds described more broadly below: AB. AB₂、A₂B、AB₅And BCC. When combined with hydrogen, these compounds form metal hydride complexes, such as MgH₂、Mg₂NiH₄、FeTiH₂And LaNi₅H₆. Examples of metals used to form metal hydrides include vanadium, magnesium, lithium, aluminum, calcium, transition metals, lanthanides, and intermetallic compounds, and solid solutions thereof.

As used herein, "active material particles" refer to material particles capable of storing hydrogen or material particles that can occlude and desorb hydrogen, such as metal hydrides. The active material may be a metal, metal alloy or metal compound capable of forming a metal hydride when exposed to hydrogen. For example, the active material may be LaNi₅FeTi, a rare earth metal mixture, a metal mixture or an ore, e.g. MmNi₅Where Mm refers to a mixture of lanthanides. The active material particles may occlude hydrogen by chemisorption, physisorption or a combination thereof. The active material particles may also include silica, alumina, zeolites, graphite, activated carbon, nano-structured carbon, micro-ceramics, nanoceramics, boron nitride nanotubes, palladium-containing materials, or combinations thereof.

As used herein, "porosity" refers to the ratio of void volume to total volume (1-volume density).

As used herein, "packing density" refers to the efficiency of active material packing. The packing density is the percentage of active material that occupies the total volume of the composite. For example, a composite material having a packing density of about 50% and a porosity of about 40% is made up of about 50% by volume active material, about 10% by volume inactive material, such as a binder or additive, and about 40% by volume voids.

As used herein, "fine powder" refers to a powder comprising particles of small size. For example, the fine powder may consist essentially of particles having a particle size of less than about 100 microns. For example, the fine powder may consist essentially of particles having a particle size of less than about 50 microns, about 10 microns, about 1 micron, or about 10 nanometers.

Referring to fig. 1, fig. 1 shows a block flow diagram of a method 100 for preparing a composite hydrogen storage material in some embodiments of the invention. The active material particles are formed 102 into a fine powder. A binder may be thoroughly mixed 104 with the fine powder to form a mixture. The mixture can be heated 106 sufficiently to form a composite hydrogen storage material wherein the binder immobilizes the active material particles sufficient to maintain relative spatial relationships between the active material particles.

The active material particles may include material particles capable of storing hydrogen or material particles that occlude and desorb hydrogen. Such as a metal hydride. An example may be LaNi₅、FeTi、Mg₂Ni and ZrV₂. The active material particles may be formed 102 into a fine powder. The fine powder may be formed, for example, by milling, such as chemical milling, ball milling, high energy ball milling, or jet milling or grinding, or by liquid metal atomization to form small particles, or a combination of these methods.

The fine powder may be mixed 104 with a binder, such as a thermoplastic binder. Examples of suitable binders include polypropylene, polyethylene, polyvinylidene fluoride (PVDF), hexafluoropropylene vinylidene fluoride copolymer, cross-linked copolymer, Polytetrafluoroethylene (PTFE), perfluoroalkoxy Polymer (PFA), thermoplastic polyester (e.g., Nylon)^TM). If a thermoplastic adhesive is used, the adhesive may, for example, be readily melt processable, and may have an elongation at break (elongation) of at least about 20%. The amount of binder may be about 50% or less by weight of the mixture. The adhesive should be flexible enough to withstand being filled inThe strain is relieved (hydrogenated/dehydrogenated) without melting or softening at the elevated temperature of the injection stage.

The mixture may be heated 106 to form a composite hydrogen storage material. For example, the porosity of the resulting composite hydrogen storage material may be from about 0.1% to about 50%. For example, the porosity of the composite hydrogen storage material may be from about 5% to about 40%, or from about 15% to about 25%. For example, the packing density of the active material added to the metal hydride composite should not be less than about 40%. For example, the packing density can be about 45% to about 90%, about 60% to about 80%, or greater than about 70%. Optionally, the composite hydrogen storage material may be pressure treated. The compression pressure can be from about 0.2MPa to about 1000MPa, or from about 100MPa to about 400 MPa. In addition, the mixture may be vibrated. Another step may also include shaping of the composite hydrogen storage material. Examples of molding include compression molding, injection molding, extrusion, or combinations thereof. The composite hydrogen storage material can be formed into a particular shape such as a prism, pellet, sheet, disc, membrane, sheet, perforated sheet, rod, or combinations thereof.

The composite hydrogen storage material may have sufficient structural strength to withstand the strain induced by the injection and release of the active material particles without causing the composite to crack through the use of a suitable binder. The structural strength of the composite hydrogen storage material allows it to be used as a load bearing member that is able to withstand the forces exerted by the metal hydride particles absorbing hydrogen. With this ability to withstand the forces generated by particle strain, the composite hydrogen storage material is able to maintain its structural integrity and remain in a solid state over multiple occlusion and desorption cycles. The composite hydrogen storage material can be made into a pellet shape, a disk shape, a sphere shape, a sheet, a rectangular sheet, or any porous shape or geometry.

Optionally, the composite hydrogen storage material may include added ingredients, additives or structures that improve the thermal or mechanical properties of the composite. Examples include graphite flakes, carbon fibers, carbon nanofibers, carbon nanotubes, polymer fibers, thermally conductive materials, metal honeycombs/lattices, metal fibers, metal wires, metal particles, glass fibers, and combinations thereof. Examples of thermally conductive materials are aluminum foil, aluminum honeycomb (aluminum honeycomb), aluminum powder, carbon fibers, carbon flakes, and the like. Examples of structural additives include carbon flakes, carbon nanotubes, glass fibers, carbon nanofibers, and combinations thereof. A lubricant may be an example of an additive. During the manufacturing process, a portion of the composite hydrogen storage material may optionally be removed to expose the added material, for example, as a thermally conductive material and structural additive.

In addition, adsorbent or absorbent materials may also be added to the composite hydrogen storage material. The adsorbent or absorbent material may adsorb or absorb materials that are toxic to the active ingredient or materials that may interfere with the hydrogenation/dehydrogenation process. Some examples may include activated carbon, calcium oxide, other readily oxidizable metals, or "oxygen getters".

Optionally, a flame retardant may also be added to the composite hydrogen storage material. Suitable specific flame retardants include, for example, ammonium phosphonium borates (i.e., phosphorus-ammonium borons); 3, 4, 5, 6-dibenzo-1, 2-oxa-phosphorus-2-oxide (3, 4, 5, 6-dibenzo-1, 2-oxa phosphine-2-oxide) or 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-Oxide (OPC) [ CAS registry No. 35948-25-5 ]; monoammonium sulfamate (ammonium sulfamate) [ CAS registry No. 7773-06-0 ]; di-n-butyltin oxide (DBTO) [ CAS registry No. 818-08-6 ]; di-n-octyltin oxide (DOTO) [ CAS registry number 780-08-6 ]; dibutyl tin diacetate and di-n-butyl tin diacetate (NS-8) [ CAS registry number 1067-33-0 ]; dibutyltin dilaurate, di-n-butyltin dilaurate (Stann BL) [ CAS registry number 77-58-7 ]; ferrocene; iron penta-carbonyl; ammonium sulfate; ammonium phosphate; zinc chloride; and mixtures thereof.

The following are examples of composite hydrogen storage materials in some embodiments of the invention and methods related thereto.

Example 1:

5 grams of LaNi having a particle size of about 1 micron or less₅The powder was mixed with 0.2 grams of 2851kyna of Atofina having a particle size of about 0.1 microns or lessrflex (polyvinylidene fluoride derivative) grade thermoplastic powders. The mixture was press molded in a mold of the desired shape at about 100MPa, 165 ℃. The mold was then cooled to room temperature while maintaining a compression pressure of 100 MPa. The resulting part removed from the mold was a porous solid composite material having a porosity of about 28%, a mass of 5.2 grams, a specific gravity of about 5.2, and LaNi₅Is about 60%.

Example 2:

5 grams of LaNi having a particle size of about 1 micron or less₅The powder was blended with 0.2 grams of graphite flake having a particle size of about 1-10 microns and 0.2 grams of an Atofina grade 2851kynarflex (polyvinylidene fluoride derivative) thermoplastic powder having a particle size of about 0.1 microns or less. The mixture was press molded in a mold of desired shape at 165 ℃ under 100 MPa. The mold was then cooled to room temperature while maintaining a compression pressure of 100 MPa. The resulting part removed from the mold was a porous solid composite material having a porosity of about 28%, a mass of 5.4 grams, a specific gravity of about 5.0, and LaNi₅Is about 56%. The addition of graphite flakes increases the strength and thermal conductivity of the composite solid. This improved performance is beneficial for improving the hydrogen injection rate and structural integrity of the component.

Example 3:

5 grams of LaNi having a particle size of about 1 micron or less₅The powder was mixed with 0.2 grams of poly-p-phenylene terephthalamide (Kevlar) fibers having a diameter of about 10 to 20 microns and a length of about 1 to 2 millimeters and 0.2 grams of a 2851kynar flex grade thermoplastic powder having an Atofina particle size of about 0.1 micron or less. The mixture was press molded in a mold of the desired shape at about 100MPa, 165 ℃. The mold was then cooled to room temperature while maintaining a compression pressure of 100 MPa. The resulting part removed from the mold was a porous solid composite material having a porosity of about 28%, a mass of 5.4 grams, a specific gravity of about 4.9, and LaNi₅The fill factor of (a) is about 53%. The addition of the poly-p-phenylene terephthalamide fiber increases the strength of the composite material.

Example 4:

5 grams of LaNi having a particle size of about 1 micron or less₅The powder was mixed with 0.2 grams of activated carbon having a particle size of about 1-10 microns and 0.2 grams of an Atofina grade 2851kynar flex (polyvinylidene fluoride derivative) thermoplastic powder having a particle size of about 0.1 microns or less. The mixture was press molded in a mold of desired shape at 165 ℃ under 100 MPa. The mold was then cooled to room temperature while maintaining a compression pressure of about 100 MPa. The resulting part removed from the mold was a porous solid composite material having a porosity of about 28%, a mass of 5.4 grams, a specific gravity of about 4.8, and LaNi₅Is about 52%. The activated carbon acts to adsorb harmful compounds that may contaminate the metal hydride during the injection process.

Referring to fig. 2, fig. 2 illustrates a block flow diagram of a method 200 for occluding and desorbing hydrogen using a composite hydrogen storage material in some embodiments of the invention. A composite hydrogen storage material 202 may be placed in a storage vessel 204 to form a composite hydrogen storage material-vessel structure 206. Hydrogen may be occluded 208 on or in a composite hydrogen storage material-vessel structure 206 sufficiently to produce a composite hydrogen storage material-vessel structure that stores hydrogen 210. The hydrogen may be desorbed 212 in preparation for another hydrogen absorption/desorption cycle for the composite hydrogen storage material-vessel structure 206. The absorption/desorption of hydrogen may be repeated many times, for example up to about 10,000 times, or up to about 100,000 times, depending on the hydride used.

The composite hydrogen storage material 202 may be placed in a storage vessel 204, such as a tank or vessel. For example, the composite hydrogen storage material 202 may be used in a porous fuel tank (cellular fuel tank), such as that described in U.S. provisional patent application 60/757,782 (attorney docket No. 2269.004PRV), entitled "cellular reserve volume and Methods related to heat", filed on 2006, 1, 9, Zimmermann, the disclosure of which is incorporated herein by reference in its entirety.

Due to its structural strength in solid form, the composite hydrogen storage material 202 serves the dual function of storing hydrogen and maintaining the hydrogen storage particles in a fixed relative spatial relationship. Thus, the composite hydrogen storage material fully fulfills the function of withstanding the strain caused by the injection of hydrogen into the material. The vessel 210 for storing hydrogen need only be designed to resist only the gas pressure of the system.

Referring to fig. 3, fig. 3 is a graphical representation of the absorption/desorption characteristics of a typical hydrogen storage material within a storage vessel. Fig. 3 shows a graph of pressure-composition-temperature (PCT) during a hydrogenation/dehydrogenation cycle for a metal hydride hydrogen storage material, such as may be used in some embodiments of the invention.

Referring to fig. 4, fig. 4 illustrates a perspective view of a storage vessel using a composite hydrogen storage material in communication with an apparatus 400 in some embodiments of the invention. The storage vessel 410 includes an outer wall 408, an optional pressure relief feature 406, and ports 404 that communicate with the external device 402. The optional pressure relief feature 406 may be a pressure relief mechanism such as a valve, spring valve, fusible trigger, rupture disk, diaphragm, or vent, which may be integral with a groove. The port 404 may be, for example, a sealable port. The external device may be, for example, a fuel cell system, a hydrogen source, a heat pump, a hydrogen compressor, or an air conditioning system. The external device 402 may also be, for example, a gas management device such as a regulator, check valve, on/off valve, or other interconnection. Alternatively, a portion of one face of the outer wall 408 may comprise, for example, a fuel cell layer, a fuel cell system, a hydrogen source, a heat pump, or a hydrogen compressor.

When used in conjunction with a fuel cell, a compact system can be formed for providing electrical power to a portable electronic device. Some examples of portable electronic devices that use the fuel cell include, but are not limited to, portable telephones, satellite telephones, portable computers, computer accessories, displays, personal audio or video players, medical devices, televisions, sensors, receivers, lighting devices including outdoor lighting or flashlights, electronic toys, or any conventional battery-operated device.

The storage vessel 410 may be small in size, and the optional pressure relief function 406 may be integrated into the design of the storage vessel 410. For larger storage vessels 410, a pressure activated or temperature activated pressure relief device may be used. For temperature activated pressure relief devices, the activation temperature may range from about 150 ℃ to about 400 ℃. For pressure activated pressure relief devices, the activation pressure may be from about 200 to about 1000psi, but also depends on the thickness and strength of the walls of the storage container 410.

Referring to fig. 5, fig. 5 illustrates a perspective view of a storage vessel 500 utilizing a composite hydrogen storage material in some embodiments of the invention. The storage vessel 500 includes an optional pressure relief feature 504 and port 506. The pressure relief function 504 is optional and can be eliminated from the design of the storage vessel, especially when the vessel is very small, or the vessel has been designed with an integral feature that can be taken out of service to allow for reasonably safe relief of internal pressure. The port 506 may be used to communicate with any number of external devices (not shown in the figures).

Referring to fig. 6, fig. 6 illustrates a cross-sectional view of a storage vessel 600 utilizing a composite hydrogen storage material disposed on an inner wall of the storage vessel in some embodiments of the invention. The storage container 600 includes an inner wall 606 and an outer wall 602. The composite hydrogen storage material 604 may be disposed within the inner wall 606 to form a space 608 between the composite hydrogen storage material 604 and the inner wall 606. The composite hydrogen storage material 604 may be in the form of a matrix that may utilize a melt processable polymer as a binder, such as polyvinylidene fluoride, polyethylene, or polypropylene. The substrate may partially or completely fill the inner space of the storage container 600.

The composite hydrogen storage material 604 may optionally be adhered to at least a portion of at least one interior wall 606 of the storage vessel 600. For example, the composite hydrogen storage material 604 may be adhered by using, for example, a melt processable polymer. Alternatively, the adhesion can be performed by gluing the composite hydrogen storage material 604 to at least a portion of at least one of the inner walls 606. For example, one example of a glue that can be used is an epoxy adhesive or a silicone glue.

Referring to fig. 7, fig. 7 illustrates a cross-sectional view of a storage vessel 700 utilizing a composite hydrogen storage material as a matrix substantially filling the storage vessel in some embodiments of the invention. The storage container 700 includes an inner wall 706 and an outer wall 702. The composite hydrogen storage material 704 may be disposed as a matrix within the inner wall 702 substantially filling the storage vessel 700.

Referring to fig. 8, fig. 8 illustrates a cross-sectional view of a storage vessel 800 utilizing a composite hydrogen storage material as multiple layers of a matrix within the storage vessel in some embodiments of the invention. The storage container 800 includes an inner wall 810 and an outer wall 802. The composite hydrogen storage material 804 may be disposed in the inner wall 802 in a plurality of layers, creating a space 806. A conductive member 808 may also optionally be placed between each layer of composite hydrogen storage material 804. In preparing the composite hydrogen storage material 804, a portion of its structure may be removed to expose the conductive member 808.

For example, the storage vessel 800 may be filled with the composite hydrogen storage material 804 to make different sized storage vessels 800 from the same base element. This allows the composite hydrogen storage material 804 to be positioned within the storage vessel 800 along with other materials, i.e., the thermally conductive member is placed around the composite hydrogen storage material 804 as shown. Some of the material may then be removed to expose portions of composite 804 having particular properties, such as exposing thermal conductive members 808 embedded within the material.

Referring to fig. 9, fig. 9 illustrates a perspective view of a composite hydrogen storage material structure 900 in some embodiments of the invention. The composite hydrogen storage material structure 900 may, for example, be formed in the shape of a rectangular sheet 902. The partial view of the cross-section illustrates the interaction of an active material 904, such as a metal hydride, and a binder 908, which may form one or more gaps or spaces 906. The voids 906 allow hydrogen to diffuse and flow between the active materials, such as metal hydride particles, to enable hydrogen to reach the interior of the formed composite hydrogen storage material.

While the invention has been particularly shown and described with reference to preferred embodiments, it will be readily understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. It is intended that the claims be interpreted to cover the disclosed embodiment, those alternatives which have been discussed above and all equivalents thereto.

The abstract is provided in accordance with c.f.r.37, clause 1.72(b) to enable the reader to quickly ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the meaning or scope of the claims.

Claims

1. A composite hydrogen storage material comprising:

active material particles capable of occluding and desorbing hydrogen; and

a thermoplastic binder;

wherein the binder elastically immobilizes the active material particles sufficient to maintain relative spatial relationships between the active material particles before, during, and after occluding and desorbing hydrogen; and is

Wherein the composite hydrogen storage material is capable of resisting forces generated by particle strain of the active material particles during occlusion and desorption of hydrogen sufficient to provide a load bearing member independent of or within the hydrogen storage vessel.

2. The composite hydrogen storage material of claim 1, wherein the active material particles occlude hydrogen by physisorption, chemisorption or combinations thereof.

3. The composite hydrogen storage material of claim 1, wherein said active material particles comprise a metal hydride.

4. The composite hydrogen storage material of claim 1, wherein the active material particles comprise AB, AB₂、A₂B、AB₅BCC type metal hydrides or combinations thereof.

5. The composite hydrogen storage material of claim 1, wherein the active material particles comprise LaNi₅FeTi or MmNi₅Where Mm refers to a mixture of lanthanide metals.

6. The composite hydrogen storage material of claim 1, wherein the active material particles comprise silica, alumina, zeolites, graphite, activated carbon, nanostructured carbon, micro-ceramics, nano-ceramics, boron nitride nanotubes, palladium containing materials or combinations thereof.

7. The composite hydrogen storage material of claim 1, wherein the thermoplastic binder is selected from the group consisting of polypropylene, polyethylene, polyvinylidene fluoride, hexafluoropropylene vinylidene fluoride copolymer, cross-linked copolymers, and combinations thereof.

8. The composite hydrogen storage material of claim 1, further comprising one or more additives.

9. The composite hydrogen storage material of claim 1, further comprising a thermally conductive additive.

10. The composite hydrogen storage material of claim 9, wherein the thermally conductive additive comprises aluminum, graphite flakes, graphite fibers, or a combination thereof.

11. The composite hydrogen storage material of claim 1, further comprising an adsorbent additive.

12. The composite hydrogen storage material of claim 11, wherein the sorbent additive is capable of adsorbing materials that would interfere with the hydrogen storage function of the active material particles.

13. The composite hydrogen storage material of claim 11, wherein the adsorbent comprises activated carbon.

14. The composite hydrogen storage material of claim 1, further comprising a structural additive.

15. The composite hydrogen storage material of claim 14, wherein the structural additive is selected from the group consisting of carbon flakes, carbon nanotubes, glass fibers, carbon nanofibers, and combinations thereof.

16. The composite hydrogen storage material of claim 1, further comprising a flame retardant.

17. The composite hydrogen storage material of claim 1, further comprising a lubricant.

18. A composite hydrogen storage material comprising:

active material particles capable of occluding and desorbing hydrogen;

a thermoplastic binder; and

one or more additives;

wherein the binder elastically immobilizes the active material particles and one or more additives sufficiently to maintain relative spatial relationships between the active material particles and the one or more additives before, during, and after occluding and desorbing hydrogen; and is

19. A composite hydrogen storage material comprising:

active material particles capable of occluding and desorbing hydrogen; and

a thermoplastic binder that elastically immobilizes the active material particles sufficient to maintain relative spatial relationships between the active material particles;

wherein the porosity of the composite hydrogen storage material is from about 0.1% to about 50%, and wherein the packing density of the active material particles is at least about 40% of the composite hydrogen storage material; and is

20. A hydrogen storage system comprising:

(A) a storage container;

(B) a composite hydrogen storage material disposed in the storage vessel, wherein said composite hydrogen storage material comprises:

active material particles capable of occluding and desorbing hydrogen; and

a thermoplastic binder;

wherein the binder elastically immobilizes the active material particles sufficient to maintain relative spatial relationships between the active material particles before, during, and after occluding and desorbing hydrogen; and

wherein the composite hydrogen storage material is capable of resisting forces generated by particle strain of the active material particles during occlusion and desorption of hydrogen sufficient to provide a load bearing member independent of or within the hydrogen storage vessel;

(C) at least one port for communicating with an external device.

21. The hydrogen storage system of claim 20, wherein said external device is a device comprising one or more of a fuel cell system, a hydrogen source, a heat pump, a hydrogen compressor, a valve, or a pressure regulator.

22. A method for preparing a composite hydrogen storage material, comprising:

(A) forming a fine powder of active material particles capable of occluding and desorbing hydrogen;

(B) mixing a thermoplastic binder with the fine powder to provide a mixture; and

(C) heating the mixture sufficiently to form a composite hydrogen storage material, wherein the binder sufficiently elastically immobilizes the active material particles to maintain a relative spatial relationship between the active material particles; and wherein the composite hydrogen storage material is capable of resisting forces generated by particle strain of the active material particles during occlusion and desorption of hydrogen sufficient to provide a load bearing member independent of or within the hydrogen storage vessel.

23. The method of claim 22, further comprising pressurizing said composite hydrogen storage material after heating said mixture.

24. The method of claim 22, further comprising applying vibration to the composite hydrogen storage material after heating the mixture.

25. The method of claim 22, further comprising mixing an additive with the binder and fine powder after milling.

26. A method of using a composite hydrogen storage material, the method comprising:

(A) occluding hydrogen on or in a composite hydrogen storage material, wherein said composite hydrogen storage material comprises:

active material particles capable of occluding and desorbing hydrogen; and

a thermoplastic binder;

wherein the binder sufficiently resiliently immobilizes the active material particles to maintain relative spatial relationships between the active material particles and the composite hydrogen storage material is capable of resisting forces generated by particle strain of the active material particles during occlusion and desorption of hydrogen sufficient to provide a load bearing member independent of or within the hydrogen storage vessel; and

(B) desorbing hydrogen from the composite hydrogen storage material.

27. The method of claim 26, further comprising occluding hydrogen on or in the composite hydrogen storage material a second time after desorbing hydrogen.

28. The method of claim 27, further comprising desorbing hydrogen from said composite hydrogen storage material a second time after occluding hydrogen on or in said composite hydrogen storage material a second time.

29. The method of claim 28, further comprising occluding and desorbing hydrogen a third or more times, up to about 100,000 times, after desorbing hydrogen from said composite hydrogen storage material a second time.

30. The method of claim 29, wherein said active material particles substantially maintain the spatial relationship between the active material particles during occlusion and desorption of hydrogen up to about 100,000 times.

31. A composite, comprising:

active material particles capable of occluding and desorbing hydrogen; and

a thermoplastic binder;

wherein the composite is formed into an unsupported shape and wherein the binder elastically immobilizes the active material particles sufficient to maintain the relative spatial relationship of the active material particles in the composite shape before, during, and after occluding and desorbing hydrogen.

32. The composite of claim 31, wherein the unsupported shape comprises a prism, a pellet, a sheet, a disk, a rod, or a combination thereof.

33. The composite of claim 31, wherein the composite is formed by heating the mixture sufficiently to sinter the binder.