JP2007229588A - Hydrogen storage material, its manufacturing method, hydrogen absorber, hydrogen storage apparatus and fuel cell-powered vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrogen storage material, its manufacturing method, a hydrogen absorber, a hydrogen storage apparatus and a fuel cell-powered vehicles. <P>SOLUTION: The hydrogen storage material 1 contains a mixed composition of a particulate inorganic material (a first inorganic material) 7 for releasing hydrogen when heated to room temperature or higher with a linear inorganic material (a second inorganic material) 8 having the thermal conductivity higher than that of the particulate inorganic material 7. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hydrogen storage material, a method for producing the hydrogen storage material, a hydrogen storage body, a hydrogen storage device, and a fuel cell vehicle.

In recent years, development competition for solid polymer fuel cells to be installed in fuel cell vehicles has been actively developed. In order to put such fuel cell vehicles into practical use, it is desired to develop an efficient hydrogen storage method using a hydrogen storage material that is low-cost, lightweight, and has a high storage density. In particular, in recent years, research on the use of a heated hydrogen-releasing type hydrogen storage material capable of releasing or absorbing hydrogen by heating to a high temperature of 100 [° C.] or more has attracted attention. Examples of the hydrogen storage material of the heated hydrogen release type include alanate materials (see Patent Documents 1 and 2) that are salts of tetrahydride aluminum ions (AlH ₄ −) that are complex ions and alkali metals, and metal amides and metal hydrogens. Amide-based materials (see Patent Documents 3 and 4) that release hydrogen by reacting a chemical compound are known.
Japanese National Patent Publication No. 11-510133 Special Table 2002-522209 Japanese Patent Laying-Open No. 2005-112698 JP 2005-95869 A

  However, in the case of using a heated hydrogen-releasing hydrogen storage material, it is necessary to heat to room temperature or higher in order to release hydrogen. In this case, it is difficult to uniformly heat the material in a short time. . In particular, when applied as an in-vehicle hydrogen storage material, it is extremely difficult to follow the amount of hydrogen released by heating, and there is a problem that sufficient hydrogen cannot be supplied during vehicle acceleration.

  Furthermore, since the heated hydrogen release type material requires a temperature higher than room temperature when hydrogen is absorbed and released, repeated use of the material causes sintering of the material particles, leading to a reduction in the surface area of the material. Such a decrease in the surface area of the material significantly reduces the hydrogen absorption / release capability and the rate of hydrogen absorption / release, and there is a problem that when applied to a vehicle, the durability against hydrogen absorption / release is reduced and the hydrogen release rate is reduced.

  The present invention has been made to solve the above problems, and a hydrogen storage material according to the present invention includes a particulate first inorganic material that is heated to room temperature or higher to release hydrogen, and the first inorganic material. It contains a mixed composition with a linear second inorganic material having higher thermal conductivity than the material.

  In the method for producing a hydrogen storage material according to the present invention, a particulate first inorganic material that releases hydrogen by heating to room temperature or higher is prepared, and a linear first material having higher thermal conductivity than the first inorganic material is prepared. The second inorganic material is prepared, and a mixture of the first inorganic material and the second inorganic material is obtained.

  The hydrogen storage body according to the present invention includes the hydrogen storage material according to the present invention.

  The hydrogen storage device according to the present invention includes the hydrogen storage body according to the present invention.

  A fuel cell vehicle according to the present invention is equipped with the hydrogen storage device according to the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the hydrogen storage material with the high responsiveness of the hydrogen release rate accompanying a heating and the improvement in repetition performance is obtained.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to manufacture reliably the hydrogen occlusion material with the high responsiveness of the hydrogen discharge | release rate accompanying heating, and the improvement in repetition performance with a simple method.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to implement | achieve the hydrogen occlusion body and the hydrogen storage apparatus with high responsiveness of the hydrogen discharge | release speed | rate accompanying heating, and high repetition performance.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel cell vehicle which is excellent in acceleration performance and can be used for a long term is obtained.

  Hereinafter, a hydrogen storage material, a method for producing a hydrogen storage material, a hydrogen storage body, a hydrogen storage device, and a fuel cell vehicle according to the best embodiment of the present invention will be described with reference to the accompanying drawings. The same members or elements are denoted by the same reference numerals, and description thereof is omitted.

  First, with reference to FIGS. 1-5, the hydrogen storage material, hydrogen storage body, and hydrogen storage apparatus which concern on embodiment of this invention are demonstrated.

  FIG. 1 is a sectional view showing an in-vehicle hydrogen storage body 2 and a hydrogen storage device 3 according to an embodiment of the present invention, FIG. 2 is a schematic view of a hydrogen storage material 1 according to an embodiment of the present invention, and FIG. 4 is a schematic diagram of a hydrogen storage material 11 according to an embodiment of the present invention, FIG. 4 is a schematic diagram of a hydrogen storage material 21 according to an embodiment of the present invention, and FIG. 5 is a hydrogen storage material 31 according to an embodiment of the present invention. FIG.

  The hydrogen storage material 1 according to the embodiment of the present invention is solidified or thinned by pressure molding and used as the hydrogen storage body 2. The hydrogen occlusion body 2 is enclosed in a pressure-resistant container 6 having a hydrogen outlet 4 shown in FIG. 1 and a heating element 5 inserted from the hydrogen outlet 4, and can be used as an in-vehicle hydrogen storage device 2. The heating element 5 is heated by electricity or a heat medium, and is connected to a heat source (not shown) disposed outside the pressure vessel 6 to heat the hydrogen storage material 1. The heating element 5 may be a resistance heating element. In this case, the heating element 5 is connected to a power source (not shown) arranged outside the pressure vessel 6. This heating element may be provided with fins or the like in order to improve the heat transfer performance, or may have a shape with irregularities on the surface.

  Such a hydrogen storage device 3 can be used by being mounted on a vehicle and incorporated in a fuel cell system or a hydrogen engine system. The shape of the pressure vessel 6 may be a shape having a simple closed space and a rib or a column inside. The material of the pressure vessel 6 is preferably selected from materials having strength and chemical stability that can withstand the absorption and release of hydrogen, such as aluminum, stainless steel, and carbon structural material. The pressure molding of the hydrogen storage material 1 may be performed before the hydrogen storage material 1 is filled in the pressure resistant container 6, or may be performed simultaneously while filling the hydrogen storage material 1.

  The hydrogen storage material 1 which concerns on embodiment of this invention is demonstrated in detail. As shown in FIG. 2, the hydrogen storage material 1 according to the embodiment of the present invention has a particulate inorganic material 7 that is heated to room temperature or higher and releases hydrogen, and has a thermal conductivity higher than that of the particulate inorganic material 7. A mixed composition with a linear inorganic material 8 having a high height is included. This hydrogen storage material 1 is sealed inside the pressure vessel 6 as a hydrogen occlusion body 2, a part of which contacts the wall surface 5 a of the electric heating material 5 in the pressure vessel 6 and is heated by the electric heating material 5.

  The particulate inorganic material 7 preferably contains an alkali metal aluminum hydride containing a metal selected from alkali metals and alkaline earth metal elements and hydrogen. Moreover, the alkali metal boron hydride or alkali metal nitrogen hydride containing the metal chosen from an alkali metal and an alkaline-earth metal element, hydrogen, and either boron or nitrogen may be sufficient. Further, it may be a mixed composition containing any one or more selected from alkali metal aluminum hydride, alkali metal boron hydride and alkali metal nitrogen hydride. More preferably, the high hydrogen absorption / release capability is obtained by mixing a compound of a transition metal of Group 3, 4 or 5 and any metal compound of a metal compound group including a rare earth compound and a hydrogen storage alloy. , And in terms of lowering the absorption / release temperature.

  The linear inorganic material 8 connects the particulate inorganic material 7 and another particulate inorganic material 7. One end 8 a of a part of the linear inorganic material 8 is in contact with the wall surface 5 a of the electric heating material 5. Further, since the linear inorganic material 8 has higher thermal conductivity than the particulate inorganic material 7, the linear inorganic material 8 acts as a medium for transferring the heat of the electric heating material 5 to the particulate inorganic material 7. Heat transfer from the vicinity of the surface of the particulate inorganic material 7 to the inside of the particulate inorganic material 7 is facilitated. For this reason, a hydrogen storage material with high responsiveness to a temperature change due to heating can be realized. In order to obtain this effect, the linear inorganic material 8 is preferably in contact with at least two particulate inorganic materials 7. Moreover, it is preferable that the heat conductivity of the linear inorganic material 8 is twice or more the heat conductivity of the particulate inorganic material 7 because a sufficient heat transfer rate and heat transfer amount can be obtained.

The linear inorganic material 8 preferably has a covalent bond, an ionic bond or a metal bond along the longitudinal direction of the linear inorganic material 8 from the viewpoint of thermal conductivity. It preferably contains mainly carbon. When the linear inorganic material 8 mainly contains carbon, the higher the thermal conductivity of the linear inorganic material 8 is, the higher the response of the hydrogen release rate with the change in heating temperature. It preferably has a good crystallinity and consists of a bond mainly composed of sp ² or sp ³ bonds. For example, examples of the linear inorganic material 8 include single-walled carbon nanotubes or multi-walled carbon nanotubes with high crystallinity. When these linear inorganic materials 8 are added, the thermal conductivity is improved as the amount added is increased, but when the amount is excessively added, the storage amount of the entire hydrogen storage material is reduced. For this reason, it is preferable to adjust the addition amount in consideration of the storage amount of the entire hydrogen storage material.

  It is preferable that the linear inorganic material 8 can store hydrogen mainly by physical adsorption or chemical adsorption. As a result, the linear inorganic material 8 has a role of storing hydrogen in addition to functioning as a heat conduction medium, and further suppresses a decrease in the hydrogen storage capacity of the entire hydrogen storage material 1 and has high thermal conductivity for heating. A hydrogen storage material having high responsiveness of the hydrogen release rate is obtained. At this time, in order to avoid that the linear inorganic material 8 itself generates heat or absorbs heat, it is desirable that the linear inorganic material 8 has a small amount of heat generation or heat absorption necessary for absorbing and releasing hydrogen.

  The linear inorganic material 8 needs to be stable at a temperature of room temperature to 400 [° C.] in a hydrogen atmosphere. Thereby, even if it heats to temperature higher than room temperature, since the particulate inorganic material 7 and the linear inorganic material 8 do not react with each other, it is possible to repeatedly absorb and release hydrogen.

Further, in order to facilitate heat transfer from the vicinity of the surface of the particulate inorganic material 7 to the inside of the particulate inorganic material 7, the length of the linear inorganic material 8 in at least one direction is a particulate inorganic material. It is preferably larger than the average particle diameter of 7. The cosine component of the linear inorganic material 8, that is, the projection length in direct irradiation is the length of the linear inorganic material 8, the average length is d _t , the cosine component of the plane perpendicular to the axis is the radius, the average radius and _{r t.} In this case, the ratio of length to mean radius of the linear inorganic material 8 can be expressed as d _{t /} r _t. In addition, when the average particle radius of the particulate inorganic material 7 is r, the linear inorganic material 8 is fastened between the particles of the adjacent particulate inorganic material 7 to promote heat conduction between the particles. Needs to satisfy d _t ≧ r.

In order for the linear inorganic material 8 to come into contact with the particulate inorganic material 7 and the entire hydrogen storage material 1 has good thermal conductivity, the hydrogen storage material 1 is composed of two particles of the inorganic inorganic material 7. On the other hand, it is preferable to contain one or more particles of the linear inorganic material 8. More preferably, the particulate inorganic material 7 contains the linear inorganic material 8 in a ratio of 12 particles or more to one particle in order to cause sufficient heat conduction. That is, the linear inorganic material 8 is 12 · π · r _t ² · dt · µ _t / ((4/3) · π · r ³ · µ _MH ) or more with respect to the particulate inorganic material 7, that is, ( it is preferably incorporated in ^{_{9r t 2 · d t / r}} 3) · (μ t / μ MH) above mass ratio. Here, μ _t and μ _MH indicate the material densities of the linear inorganic material 8 and the particulate inorganic material 7, respectively. For example, when r = 30 [μm], r _t = 1 [μm], μ _t = 0.5 [g / cm ³ ], μ _MH = 1.0 [g / cm ³ ] It is preferable that the inorganic material 7 is mixed at a mass ratio of about 0.5 [wt%] or more.

  When the particulate inorganic material is used alone as the hydrogen storage material, the particulate inorganic material 7 aggregates (sinters) because the hydrogen storage reaction of the particulate inorganic material is performed at a relatively high temperature. . For this reason, hydrogen storage ability falls and it cannot endure repeated use. On the other hand, since the hydrogen storage material 1 according to the embodiment of the present invention is composed of a mixed composition of the particulate inorganic material 7 and the linear inorganic material 8, the linear inorganic material 8 is particulate. Aggregation of the inorganic material 7 is suppressed. For this reason, the repetition performance of the hydrogen storage material 1 is improved.

  The linear inorganic material is for efficiently transferring heat from the surface of the hydrogen storage material to the inside of the hydrogen storage material, and is not limited to the linear inorganic material 8 shown in FIG. Other shapes may be used as long as the shape is an inorganic material. For example, like the hydrogen storage material 11 shown in FIG. 3, the inorganic material 18 may have a dendritic shape that branches in a dendritic manner from one end 18 a in contact with the wall surface 5 a of the heating element 5. Moreover, like the hydrogen storage material 21 shown in FIG. 3, the one end 28a may be a two-dimensional or three-dimensional network network in contact with the wall surface 5a of the heating element 5, and the hydrogen storage material 31 shown in FIG. Thus, the one end 38 a of the inorganic material 38 may have a spiral shape when it contacts the wall surface 5 a of the heating element 5.

  As described above, the hydrogen storage material according to the embodiment of the present invention includes a particulate inorganic material that is heated to room temperature or more to release hydrogen, and a linear inorganic material that has higher thermal conductivity than the particulate inorganic material. The hydrogen storage material with high responsiveness of the hydrogen release rate accompanying heating and improved repeatability can be obtained.

  Further, the hydrogen storage body according to the embodiment of the present invention uses a hydrogen storage material that is easy to transfer heat to the inside of the hydrogen storage material, has a high responsiveness of the hydrogen release rate accompanying heating, and has improved repeatability. Therefore, a hydrogen occlusion body having high responsiveness with heat application to the heat exchanger or the heater and high repeatability can be obtained. In addition, since the hydrogen storage device includes the hydrogen storage device, the hydrogen storage device according to the embodiment of the present invention realizes a hydrogen storage device that has high responsiveness with heat application to the heat exchanger or the heater and high repetition performance. Is possible.

  Next, the manufacturing method of the hydrogen storage material which concerns on embodiment of this invention is demonstrated. This method for producing a hydrogen storage material is prepared by preparing a particulate inorganic material that releases hydrogen when heated to room temperature or higher, preparing a linear inorganic material having higher thermal conductivity than the particulate inorganic material, A mixture of a linear inorganic material and a linear inorganic material is obtained. This method for producing a hydrogen storage material includes a mixed composition of a particulate inorganic material that releases hydrogen when heated to room temperature or higher and a linear inorganic material that has higher thermal conductivity than the particulate inorganic material. It becomes possible to reliably manufacture the hydrogen storage material by a simple method.

  When obtaining a mixture, it is preferable to physically mix two or more kinds of particulate inorganic materials and linear inorganic materials simultaneously. This physical mixing includes ball milling with a grinding medium, and ball milling is preferably performed in an inert atmosphere or a hydrogen atmosphere in order to prevent a rapid reaction.

  As described above, according to the method for producing a hydrogen storage material according to the embodiment of the present invention, the particulate inorganic material that is heated to room temperature or more to release hydrogen and the thermal conductivity is higher than that of the particulate inorganic material. By including a mixed composition with a linear inorganic material, it is possible to reliably produce a hydrogen storage material with high responsiveness of the hydrogen release rate upon heating and improved repeatability by a simple method. .

  Next, a fuel cell vehicle according to an embodiment of the present invention will be described. FIG. 6 shows a fuel cell vehicle 40 equipped with the hydrogen storage device 3 according to the embodiment of the present invention. At this time, the hydrogen storage device 3 installed and mounted on the fuel cell vehicle 40 may be divided into one or two or more, and the shapes of the plurality of hydrogen storage devices may be different. In addition to the interior of the engine room or the trunk room or the interior of the vehicle compartment such as the floor portion under the seat, the hydrogen storage device 3 can be installed outside the interior of the vehicle compartment such as the upper part of the roof.

  The fuel cell vehicle according to the present embodiment is equipped with a hydrogen storage device that is highly responsive to heat application to the heat exchanger or heater and has high repeatability, so that hydrogen can be generated quickly during acceleration. This makes it possible to sufficiently supply the hydrogen necessary for vehicle acceleration to the fuel cell, thereby obtaining a fuel cell vehicle that has excellent acceleration performance and can be used for a long time.

  Hereinafter, the present invention will be described more specifically with reference to Examples 1 to 6 and Comparative Examples 1 to 2, but the scope of the present invention is not limited thereto. In Examples 1 to 6 and Comparative Examples 1 to 2, the addition ratio of the linear inorganic material having high thermal conductivity is changed.

1. Sample Preparation Example 1
NaAlH ₄ was used as the particulate inorganic material. Under an Ar atmosphere, titanium chloride and NaAlH ₄ were suspended in an ether solution to remove the ether. The addition amount of Ti ions was 2 [mol%]. The obtained Ti-added NaAlH ₄ and single-walled carbon nanotubes, which are linear inorganic materials, were physically mixed in an agate mortar under an Ar atmosphere. The amount of single-walled carbon nanotube added was 3 [wt%].

Example 2
NaAlH ₄ was used as the particulate inorganic material. Under an Ar atmosphere, titanium chloride and NaAlH ₄ were suspended in an ether solution to remove the ether. The addition amount of Ti ions was 2 [mol%]. The obtained Ti-added NaAlH ₄ and single-walled carbon nanotubes, which are linear inorganic materials, were physically mixed in an agate mortar under an Ar atmosphere. The addition amount of the single-walled carbon nanotube was 5 [wt%].

Example 3
NaAlH ₄ was used as the particulate inorganic material. Under an Ar atmosphere, titanium chloride and NaAlH ₄ were suspended in an ether solution to remove the ether. The addition amount of Ti ions was 2 [mol%]. The obtained Ti-added NaAlH ₄ and single-walled carbon nanotubes, which are linear inorganic materials, were physically mixed in an agate mortar under an Ar atmosphere. The addition amount of the single-walled carbon nanotube was 10 [wt%].

Example 4
LiNH ₂ and LiH were used as particulate inorganic materials. The mixture was mixed so that the mixing ratio of LiNH ₂ and LiH was 2: 1, and single-walled carbon nanotubes, which are linear inorganic materials, were added by 3 [wt%] and then physically mixed by a ball mill for 5 [hours].

Example 5
LiNH ₂ and LiH were used as particulate inorganic materials. The mixture was mixed so that the mixing ratio of LiNH ₂ and LiH was 2: 1, and single-walled carbon nanotubes, which are linear inorganic materials, were added 5 wt%, and then physically mixed by a ball mill for 5 hours.

Example 6
LiNH ₂ and LiH were used as particulate inorganic materials. The mixture was mixed so that the mixing ratio of LiNH ₂ and LiH was 2: 1, and single-walled carbon nanotubes, which are linear inorganic materials, were added by 10 [wt%], and then physically mixed by a ball mill for 5 [hours].

Comparative Example 1
NaAlH ₄ was used as the particulate inorganic material. Under an Ar atmosphere, titanium chloride and NaAlH ₄ were suspended in an ether solution to remove the ether. The addition amount of Ti ions was 2 [mol%]. The obtained Ti-added NaAlH ₄ was physically pulverized in an agate mortar under an Ar atmosphere.

Comparative Example 2
LiNH ₂ and LiH were used as particulate inorganic materials. The mixture was mixed so that the mixing ratio of LiNH ₂ and LiH was 2: 1, and physical mixing was performed by a ball mill for 5 hours.

2. Measurement of hydrogen storage capacity of hydrogen storage materials
Hydrogen release performance was measured for the samples obtained in Examples 1 to 6 and Comparative Examples 1 to 2. First, the hydrogen storage material was subjected to absorption / release treatment by the PCT method (JIS H 7201). The hydrogen releasing reaction was 100 [° C.], and the hydrogen storage reaction was 300 [° C.]. The hydrogen release-storage reaction was repeated for 3 cycles, and then kept at room temperature, and the hydrogen release rate was measured by differential thermogravimetry. The differential thermogravimetry was performed in an Ar atmosphere, and the rate of temperature increase was set to 1 [° C./min] to 50 [° C./min], and the maximum temperature was 300 [° C.]. Sample 20 [mg] was used for the measurement.

Table 1 shows the relationship between the heating rate of Examples 1 to 3 and Comparative Example 1 using NaAlH ₄ as the particulate inorganic material and the hydrogen releasing ability when reaching 300 [° C.]. .

In Comparative Example 1, the hydrogen release amount tends to decrease rapidly as the temperature increase rate increases, but in Examples 1 to 3, the hydrogen release amount increases rapidly even when the temperature increase rate increases. It was found that the decrease in hydrogen releasing ability was suppressed without decreasing. In addition, a decrease in hydrogen releasing ability was suppressed when the amount of single-walled carbon nanotubes added as a linear inorganic material was large. From this, it is considered that the single-walled carbon nanotube has high thermal conductivity and facilitates heat transfer of NaAlH ₄ , so that the responsiveness to the temperature change due to heating of the hydrogen storage material is increased.

Table 2 shows the relationship between the rate of temperature increase in Examples 4 to 6 and Comparative Example 2 and the hydrogen releasing ability when reaching 300 [° C.].

Even when LiNH ₂ and LiH were used as the particulate inorganic material, the same result as that obtained when NaAlH ₄ was used as the particulate inorganic material was obtained. That is, in Comparative Example 2, the hydrogen release amount tends to decrease rapidly as the temperature increase rate increases, but in Examples 4 to 6, the hydrogen release amount is increased even when the temperature increase rate increases. It turned out that it did not fall rapidly and the fall of hydrogen releasing ability was suppressed. In addition, a decrease in hydrogen releasing ability was suppressed when the amount of single-walled carbon nanotubes added as a linear inorganic material was large.

  From the above results, it was found that the hydrogen storage materials obtained in Examples 1 to 6 had improved hydrogen release response performance.

  Although the embodiment of the present invention has been described above, it should not be understood that the description and drawings that constitute part of the disclosure of the embodiment limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

It is sectional drawing which shows the hydrogen storage body and hydrogen storage apparatus which concern on embodiment of this invention. It is a schematic diagram which shows an example of the hydrogen storage material which concerns on embodiment of this invention. It is a schematic diagram which shows an example of the hydrogen storage material which concerns on embodiment of this invention. It is a schematic diagram which shows an example of the hydrogen storage material which concerns on embodiment of this invention. It is a schematic diagram which shows an example of the hydrogen storage material which concerns on embodiment of this invention. 1 is a side view showing a fuel cell vehicle according to an embodiment of the present invention.

Explanation of symbols

1 Hydrogen storage material 7 Particulate inorganic material (first inorganic material)
8 Linear inorganic material (second inorganic material)

Claims (20)

A particulate first inorganic material that is heated above room temperature and releases hydrogen;
A hydrogen storage material comprising a mixed composition with a linear second inorganic material having higher thermal conductivity than the first inorganic material.   2. The hydrogen storage material according to claim 1, wherein the thermal conductivity of the second inorganic material is twice or more that of the first inorganic material.   The hydrogen storage material according to claim 1, wherein the second inorganic material mainly contains carbon.   The hydrogen storage material according to any one of claims 1 to 3, wherein the second inorganic material is capable of storing hydrogen.   The hydrogen storage material according to any one of claims 1 to 4, wherein the second inorganic material includes a one-dimensional manifold-like inorganic material.   The hydrogen storage material according to claim 5, wherein the second inorganic material has a covalent bond, an ionic bond, or a metal bond along a longitudinal direction of the one-dimensional manifold-like inorganic material. .   The hydrogen storage material according to claim 5, wherein the second inorganic material includes single-walled carbon nanotubes or multi-walled carbon nanotubes.   8. The hydrogen according to claim 5, wherein the second inorganic material has a length in at least one direction larger than an average particle diameter of the first inorganic material. 9. Storage material.   9. The hydrogen storage material according to claim 5, wherein the hydrogen storage material contains one or more particles of the second inorganic material with respect to two particles of the first inorganic material. 10. Hydrogen storage material.   The first inorganic material includes a first material containing a metal selected from an alkali metal and an alkaline earth metal element, and hydrogen. 2. A hydrogen storage material according to 1.   The first inorganic material includes a second material containing a metal selected from an alkali metal and an alkaline earth metal element, hydrogen, and either boron or nitrogen. Item 11. The hydrogen storage material according to any one of Items 9.   The first inorganic material includes a metal selected from an alkali metal and an alkaline earth metal element, a first material containing hydrogen, a metal selected from an alkali metal and an alkaline earth metal element, hydrogen, The hydrogen storage material according to any one of claims 1 to 9, comprising a mixed composition with a second material containing either boron or nitrogen. Preparing a particulate first inorganic material that releases hydrogen by heating above room temperature;
Preparing a linear second inorganic material having higher thermal conductivity than the first inorganic material;
A method for producing a hydrogen storage material, wherein a mixture of the first inorganic material and the second inorganic material is obtained.   The method for producing a hydrogen storage material according to claim 13, wherein two or more kinds of the first inorganic material and the second inorganic material are simultaneously physically mixed to obtain the mixture.   The method for producing a hydrogen storage material according to claim 14, wherein the physical mixing includes ball milling using a grinding medium.   The method for producing a hydrogen storage material according to claim 15, wherein the ball milling is performed in an inert atmosphere or a hydrogen atmosphere.   A hydrogen storage material comprising the hydrogen storage material according to any one of claims 1 to 12.   A hydrogen storage device comprising the hydrogen storage body according to claim 17.   The hydrogen storage device according to claim 18, wherein the hydrogen storage body is sealed in a pressure tank.   A fuel cell vehicle equipped with the hydrogen storage device according to claim 19.

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