Hydrogen storage material

Abstract

To provide a hydrogen storage material having high hydrogen storage capacity and low hydrogen release temperature.SOLUTION: A hydrogen storage material of an embodiment includes a metal body powder and a metal-supporting powder. The metal body powder includes a metal body element as a component. The metal-supported powder contains a metal-supporting element other than the metal main body element as a component and is supported on the metal main body powder. The metal body powder is at least one of a metal Mg powder containing Mg as a metal body element and a metal Li powder containing Li as a metal body element. Here, the bonding energy E1 between the metallic main body element and the hydrogen atoms and the bonding energy E2 between the metallic main body element and the metal-supporting element have a relationship represented by "E1 <E2".SELECTED DRAWING: FIG. 1A

Description

[Technical Field]

[0001] FIELD OF THE INVENTION Embodiments of the present invention relate to hydrogen storage materials. [Background technology]

[0002] A hydrogen storage material is a material that can reversibly store and release hydrogen. An example of a hydrogen storage material is metallic magnesium (simple Mg). When metallic magnesium combines with hydrogen, a hydride (MgH2) is produced.

[0003] Metallic magnesium has a high hydrogen storage capacity. Specifically, the theoretical hydrogen storage capacity of rare earth alloys such as LaNi5 and TiFe alloys is approximately 1.4 wt%, while that of metallic magnesium is 7.5 wt%.

[0004] Metallic magnesium is a material with strong reducing power, and its reduced hydride (MgH2) is a very stable compound with a high enthalpy of hydrogenation (-74 kJ / mol). Because of this, metallic magnesium has a relatively high hydrogen release temperature (approximately 400°C), and there is a demand for a lower hydrogen release temperature. In addition, metallic magnesium (Mg) requires a relatively high activation treatment temperature when it is first used, and there is a demand for a lower activation treatment temperature.

[0005] In order to meet the above demands, various techniques have been proposed. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 1270634 [Patent Document 2] WO2008 / 032774 [Patent Document 3] Patent No. 3383692 [Non-patent literature]

[0007]

Non - Patent Document 1

Non - Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, conventionally, it has not been easy to achieve a decrease in the hydrogen release temperature while maintaining a high hydrogen storage capacity. Similarly, in the case of a hydrogen storage material containing metallic lithium as a component in addition to metallic magnesium, it has not been easy to achieve a decrease in the hydrogen release temperature while maintaining a high hydrogen storage capacity.

[0009] Therefore, the problem to be solved by the present invention is to provide a hydrogen storage material having a high hydrogen storage capacity and a low hydrogen release temperature.

Means for Solving the Problems

[0010] The hydrogen storage material of the embodiment has a metal main - body powder and a metal - supported powder. The metal main - body powder contains a metal main - body element as a component. The metal - supported powder contains a metal - supported element other than the metal main - body element as a component and is supported on the metal main - body powder. The metal main - body powder is at least one of a metal Mg powder containing Mg as the metal main - body element and a metal Li powder containing Li as the metal main - body element. Here, the binding energy E1 between the metal main - body element and a hydrogen atom and the binding energy E2 between the metal main - body element and the metal - supported element are in the relationship shown in the following (Equation 1). E1 < E2 ···(Equation 1)

Effects of the Invention

[0011] According to the present invention, it is possible to provide a hydrogen storage material having a high hydrogen storage capacity and a low hydrogen release temperature. [Brief explanation of the drawings]

[0012] [Figure 1A] FIG. 1A is a diagram schematically illustrating a hydrogen storage material 1 according to an embodiment. [Figure 1B] Figure 1B is a diagram showing the bonds between the metal body element 10a, which is a component of the metal body powder 10, the metal support element 20a, which is a component of the metal support powder 20, and the hydrogen atoms 30a stored in the hydrogen storage material 1 according to the embodiment. [Figure 2A] FIG. 2A is a graph showing the results of evaluating the interaction energy acting between the elements constituting the hydrogen storage material 1 when a hydrogen atom is extracted from a lattice site of the hydrogen storage material 1 in an embodiment. [Figure 2B] FIG. 2B is a diagram schematically showing a metallurgical bonded portion between the metal body powder 10 and the metal-supported powder 20 in the hydrogen storage material 1 of the embodiment. [Figure 3] FIG. 3 is a flow diagram showing an outline of a manufacturing method for producing the hydrogen storage material 1 of the embodiment. [Figure 4] FIG. 4 is a diagram schematically showing a state in which plasma sintering is performed in the manufacturing method for producing the hydrogen storage material 1 of the embodiment. [Figure 5A] FIG. 5A is a graph showing the relationship between temperature and the amount of released hydrogen for the hydrogen storage material 1 of the embodiment. [Figure 5B] FIG. 5B is a graph showing the relationship between temperature and hydrogen storage capacity for the hydrogen storage material 1 of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] [A] Overview of hydrogen storage material composition FIG. 1A is a diagram schematically illustrating a hydrogen storage material 1 according to an embodiment.

[0014] As shown in Fig. 1A, the hydrogen storage material 1 of the present embodiment includes a metal main body powder 10 and a metal supported powder 20.

[0015] In the hydrogen storage material 1, the metal main body powder 10 contains a metal main body element as a component. The metal main body powder 10 is, for example, a metal Mg powder containing Mg as the metal main body element. The metal Mg powder is a powder composed of Mg (magnesium) alone. Of course, the metal Mg powder may contain impurities in addition to Mg alone.

[0016] In the hydrogen storage material 1, the metal supported powder 20 is supported on the metal main body powder 10. The metal supported powder 20 contains a metal supported element as a component. The metal supported element is other than the metal main body element constituting the metal main body powder 10. The metal supported powder 20 of the present embodiment is, for example, a powder composed of Ni (nickel) alone. Of course, the metal supported powder 20 may contain impurities in addition to Ni alone.

[0017] Fig. 1B is a diagram schematically showing the bonds between the metal main body element 10a which is a component of the metal main body powder 10, the metal supported element 20a which is a component of the metal supported powder 20, and the hydrogen atoms 30a stored in the hydrogen storage material 1 in the hydrogen storage material 1 according to the embodiment. Here, the hydrogen atoms 30a constitute a hydride (for example, MgH2) of the metal main body element 10a.

[0018] When hydrogen atoms 30a are stored in the hydrogen storage material 1 (see Fig. 1A) of the present embodiment, as shown in Fig. 1B, the metal main body element 10a and the hydrogen atoms 30a are in a state of being bonded with a bonding energy E1. Also, the metal main body element 10a and the metal supported element 20a are in a state of being bonded with a bonding energy E2. The hydrogen storage material 1 of the present embodiment is configured such that the bonding energy E1 between the metal main body element 10a and the hydrogen atoms 30a and the bonding energy E2 between the metal main body element 10a and the metal supported element 20a satisfy the relationship shown in the following (Equation 1).

[0019] E1 < E2 ···(Equation 1)

[0020] In the hydrogen storage material 1 of this embodiment, the bond energy E1 between the metal body element 10a and the hydrogen atoms 30a is reduced by the action of the metal support element 20a. That is, in the hydrogen storage material 1 of this embodiment, the bond between the metal body element 10a and the hydrogen atoms 30a becomes less stable due to Coulomb interaction than in the case where the metal support element 20a is not present.

[0021] Therefore, the hydrogen storage material 1 of this embodiment can achieve a lower hydrogen release temperature while maintaining a high hydrogen storage capacity.

[0022] [B] Detailed structure of hydrogen storage material [B-1] Materials The metal body powder 10 may be a metallic Li powder containing Li as the metal body element, in addition to metallic Mg powder. The metal body powder 10 may also be a mixture of metallic Mg powder and metallic Li powder. In this case, too, the hydrogen storage capacity of the hydrogen storage material 1 can be improved.

[0023] In the metal-supported powder 20, the metal-supported element 20a is preferably Co (cobalt) or Cu (copper) in addition to the above-mentioned Ni (nickel). The metal-supported element 20 does not need to be a single element, and may be a combination of multiple elements including these elements.

[0024] The bond energy E1 between the metal body element 10a and the hydrogen atom 30a is approximately 170 kJ / mol when the metal support element 20a is also Mg (magnesium). The bond energy E1 between the metal body element 10a and the hydrogen atom 30a is approximately 35 kJ / mol when the metal support element 20a is Ni (nickel), approximately 30 kJ / mol when the metal support element 20a is Co (cobalt), and approximately 15 kJ / mol when the metal support element 20a is Cu (copper). Each value was obtained by a simple quantum chemical calculation using the density functional theory.

[0025] As can be seen from this, when the metal body element 10a is Mg (magnesium) and the metal support element 20a is Ni (nickel), Co (cobalt), or Cu (copper), the relationship shown in the above-mentioned (Equation 1) is fully satisfied, and therefore the above-mentioned actions and effects can be obtained.

[0026] FIG. 2A is a graph showing the results of evaluating the interaction energy acting between the elements constituting the hydrogen storage material 1 when a hydrogen atom is extracted from a lattice site of the hydrogen storage material 1 in an embodiment.

[0027] In Fig. 2A, the horizontal axis represents the displacement D (Å) of a hydrogen atom from its lattice position, and the vertical axis represents the interaction energy IE (kJ / mol). Fig. 2A shows the results when the metal body powder 10 is a metallic Mg powder and the metal-supported powder 20 is a metallic Ni powder (Ni-supported), a metallic Co powder (Co-supported), or a metallic Cu powder (Cu-supported). Also, Fig. 2A shows the results when the metal body powder 10 is a metallic Mg powder and there is no metal-supported powder 20 (unsupported).

[0028] When the metal-supported powder 20 is a metallic Ni powder (Ni-supported) or a metallic Co powder (Co-supported), the absolute value of the gradient of the interaction energy at the lattice site is large, and the stable position where the energy is at a minimum value is far from the lattice site, as shown in Figure 2A. Therefore, since the gradient of the energy (distance differential) corresponds to a force, the hydrogen atoms are subjected to a force in the direction from the lattice site to the stable position, and the hydrogen atoms are more likely to be released.

[0029] When the metal-supported powder 20 is a metallic Cu powder (Cu-supported), the difference between the maximum and minimum values ​​of the interaction energy is small, as shown in Fig. 2A. Therefore, the energy required to move a hydrogen atom from a lattice position to infinity is small, and the hydrogen atom is more likely to be released.

[0030] [B-2] Average particle size The average particle size R10 of the metal body powder 10 is preferably 10 μm or less (R10≦10 μm), and the average particle size R20 of the metal-supported powder 20 is preferably 100 nm or less (R20≦100 nm).

[0031] In the hydrogen storage material 1 of this embodiment, the effect of the metal support element making the bond between the metal body element and hydrogen atoms unstable is exhibited when the metal support element is in a state where it is several atomic layers, so it is more preferable that the average particle diameter R20 of the metal support powder 20 is about 10 nm. Furthermore, in consideration of the thermodynamic movement of hydrogen atoms in the metal body powder 10, it is more preferable that the average particle diameter R10 of the metal body powder 10 is about 100 nm and that it contains many crystal grain boundaries. This shortens the distance that hydrogen atoms diffuse from the interior of the powder to the surface, and increases the surface area of ​​the surface where hydrogen atoms are absorbed and released, making it easier to absorb and release hydrogen atoms.

[0032] The test method for the "average particle size" mentioned above is a method conforming to JIS Z8890.

[0033] [B-3] Loading ratio In the hydrogen storage material 1 of this embodiment, the loading ratio of the metal body powder 10 to the metal-supported powder 20 preferably satisfies the relationship that the amount of metal support element W20 in the metal-supported powder 20 is 10 atomic % or less relative to the total amount (W10 + W20) of the amount of metal body element W10 in the metal body powder 10 and the amount of metal support element W20 in the metal-supported powder 20. (100 W20 / (W10 + W20) ≦ 10 atomic %). Outside this range, aggregation of the metal-supported powder 20 may occur, resulting in a decrease in the hydrogen storage capacity per unit weight.

[0034] [B-4]Void The hydrogen storage material 1 of this embodiment is a sintered body of the metal body powder 10, and preferably contains voids. This is to accommodate the volume expansion of about 10% when the metal body powder 10 absorbs hydrogen. Here, it is preferable that the voids be at least about 10 to 20% by volume in order to maintain the shape of the sintered body.

[0035] When hydrogen is stored and released in the hydrogen storage material 1 of this embodiment, the volume of the hydrogen storage material 1 changes, which may cause the metal body powder 10 to crack and pulverize. As the metal body powder 10 pulverizes, the metal-supported powder 20 may peel off or fall off from the metal body powder 10. Furthermore, pulverization may cause the powder to be unevenly located, which may change the thermal conductivity when heat is conducted to the powder. Due to such phenomena, the hydrogen absorption / release characteristics may differ from the initial state, and if the metal body powder is localized, localized heat may be generated during hydrogen absorption. However, as described above, when voids are present, such volume changes are permitted, making it possible to prevent such problems from occurring.

[0036] The sintered body containing voids is formed by, for example, subjecting the hydrogen storage material 1 to plasma sintering.

[0037] [B-5] Removal of native oxide film In the hydrogen storage material 1 of this embodiment, it is preferable that the surface of the metal body powder 10 is not covered with a natural oxide film, and that the surface of the metal body powder 10 is exposed as a metal body element (metal Mg, etc.). Also, in the hydrogen storage material 1 of this embodiment, it is preferable that the surface of the metal-supported powder 20 is not covered with a natural oxide film, and that the surface of the metal-supported powder 20 is exposed as a metal-supported element (metal Ni, etc.). In the hydrogen storage material 1, the natural oxide film acts as a barrier when absorbing hydrogen and also acts as a barrier when releasing hydrogen, but if the material is not covered with a natural oxide film, there is no barrier, and therefore hydrogen absorption and release are carried out appropriately.

[0038] The native oxide film is removed by, for example, an activation process. For example, the native oxide film is destroyed by rapidly heating and rapidly cooling the hydrogen storage material 1 in a hydrogen atmosphere to generate a large difference in thermal expansion, or by repeatedly heating and cooling at high temperatures to generate a large difference in volume expansion. The native oxide film is also destroyed by dielectric breakdown due to a large current. Alternatively, the native oxide film is removed by plasma sintering the hydrogen storage material 1.

[0039] By removing the natural oxide film, the hydrogen storage material 1 of this embodiment includes a portion where the metal body powder 10 and the metal-supported powder 20 are joined by metal bonding.

[0040] FIG. 2B is a diagram schematically showing a metallurgical bonded portion between the metal body powder 10 and the metal-supported powder 20 in the hydrogen storage material 1 of the embodiment.

[0041] As described above, in the hydrogen storage material 1 of this embodiment, the bond energy between the metal body element 10a (e.g., Mg) and the hydrogen atoms 30a is reduced by the action of the metal support element 20a, and the bond between the metal body element 10a and the hydrogen atoms 30a is unstable. Furthermore, hydrogen diffuses quickly in the metal-supported powder 20 (e.g., metal Ni), and hydrogen absorption and release occur easily. In other words, the metal-supported powder 20 (e.g., metal Ni) serves as a pathway for hydrogen absorption and release. Therefore, at the portion AA where the metal body powder 10 and the metal-supported powder 20 come into contact and form a metal bond, hydrogen molecules dissociate or bond preferentially compared to other portions (see FIG. 2B ).

[0042] As a result, when hydrogen is released, the hydrogen concentration decreases in the part AA where the metal body powder 10 and the metal-supported powder 20 come into contact and form a metal bond, so that hydrogen present in the part adjacent to the part AA can more easily move to the part AA.

[0043] On the other hand, when hydrogen is absorbed, the hydrogen concentration increases in the part AA where the metal body powder 10 and the metal-supported powder 20 come into contact and form a metal bond, making it easier for hydrogen to move from the part AA to the part adjacent to the part AA.

[0044] Therefore, in this embodiment, hydrogen absorption and release are smoothly performed. Also, the activation process performed in the initial stage can be omitted or the conditions can be relaxed.

[0045] [B] Manufacturing method A method for producing the hydrogen storage material 1 (see FIG. 1A) of this embodiment will be described.

[0046] FIG. 3 is a flow diagram showing an outline of a manufacturing method for producing the hydrogen storage material 1 of the embodiment.

[0047] When the hydrogen storage material 1 of this embodiment is produced, for example, a preparation step (ST10), a supporting step (ST20), and a post-treatment step (ST30) are carried out in this order, as shown in Fig. 3. Each step will be described in turn.

[0048] [B-1] Preparation process (ST10) In the preparation step (ST10), raw materials for the hydrogen storage material 1 are prepared.

[0049] Here, as raw materials for the hydrogen storage material 1, for example, metallic Mg powder is prepared as the metal body powder 10 and metallic Ni powder is prepared as the metal support powder 20 shown in FIG. 1A.

[0050] [B-2] Supporting step (ST20) In the supporting step (ST20), the metal-supported powder 20 is supported on the metal body powder 10.

[0051] Here, for example, the metal body powder 10 and the metal-supported powder 20 prepared in the preparation step (ST10) are put into a solvent and mixed to prepare a slurry. The solvent is preferably a non-polar substance that does not react with the metal body powder 10 and the metal-supported powder 20.

[0052] Then, the slurry is subjected to a crushing process. The crushing process is performed using, for example, an attritor. Specifically, the above-mentioned slurry and ceramic balls are put into a tank, and the slurry and balls are stirred in the tank, thereby crushing the metal body powder 10 and the metal-supported powder 20. The crushing process is performed in an inert gas (argon (Ar) gas, etc.) atmosphere.

[0053] Thereafter, the slurry is dried to obtain the hydrogen storage material 1 in which the metal-supported powder 20 is supported on the metal-body powder 10.

[0054] The crushing process may be performed by a dry method in addition to the wet method described above. For example, stirring may be performed by colliding gas at high speed. Furthermore, cooling may be performed to improve the efficiency of the crushing process. In addition, the size of the metal body powder 10 may be reduced, or a hydride may be used as the metal body powder 10. This reduces the ductility of the metal body powder 10, allowing the crushing process to be performed efficiently.

[0055] [B-3] Post-processing process (ST30) In the post-treatment step (ST30), the hydrogen storage material 1 in which the metal-supported powder 20 is supported on the metal body powder 10 is subjected to post-treatment.

[0056] Here, for example, plasma sintering is performed as post-treatment to remove the native oxide film and form voids. The post-treatment is not essential but is optional.

[0057] FIG. 4 is a diagram schematically showing a state in which plasma sintering is performed in the manufacturing method for producing the hydrogen storage material 1 of the embodiment.

[0058] When performing plasma sintering, first, the hydrogen storage material 1 is placed in a sintering mold 100 made of, for example, carbon. Next, the hydrogen storage material 1 placed in the sintering mold 100 is pressurized and heated by passing a pulse current. This generates plasma, which destroys the natural oxide films formed on the surfaces of the metal body powder 10 and the metal-supported powder 20. Furthermore, the powders are slightly fused together, creating a sintered body.

[0059] Plasma sintering is performed, for example, in a state where voids exist in the accommodation space in the sintering mold 100 where the hydrogen storage material 1 is accommodated. For example, plasma sintering is performed under conditions where voids of about 10% exist in the accommodation space. This results in a sintered body with voids of about 10%. As a result, pulverization of the hydrogen storage material 1 due to repeated hydrogen absorption and desorption can be suppressed.

[0060] In order to prevent pulverization, sintering may be performed by impregnating the material with carbon nanofibers or the like.

[0061] [B-4] Modified manufacturing method In the above supporting step (ST20), a case has been described in which a slurry is prepared by mixing the metal body powder 10 and the metal-supported powder 20, but the present invention is not limited to this.

[0062] The supporting step (ST20) may be performed by an electric explosion method. In this case, first, fine metal wires made of a metal body element 10a (e.g., Mg) and fine metal wires made of a metal support element 20a (e.g., Ni) are prepared. The number and thickness of the fine metal wires are adjusted as needed. Then, an electric current is passed through each fine metal wire in a rare gas, causing each fine metal wire to sublimate. Then, at the timing when the sublimated substance, for example, Mg, sublimates onto the rare gas atoms, Ni sublimes onto the Mg, forming the metal body powder 10 and the metal-supported powder 20, and the hydrogen storage material 1 in which the metal-supported powder 20 is supported on the metal body powder 10 is produced.

[0063] In addition, for example, the above-mentioned loading step (ST20) may be performed by a sputtering method to produce the hydrogen storage material 1 in which the metal-supported powder 20 is supported on the metal body powder 10.

[0064] [C] Summary As described above, the hydrogen storage material 1 of the present embodiment includes a metal body powder 10 containing a metal body element as a component, and a metal-supported powder 20 containing a metal-supported element other than the metal body element as a component and supported on the metal body powder 10. Here, the metal body powder 10 is at least one of a metal Mg powder containing Mg as a metal body element and a metal Li powder containing Li as a metal body element. Here, as described above, the hydrogen storage material 1 is configured such that the binding energy E1 between the metal body element and the hydrogen atom and the binding energy E2 between the metal body element and the metal-supported element satisfy the relationship shown in the following (Equation 1). Therefore, it is possible to realize a decrease in the hydrogen release temperature while maintaining a high hydrogen storage capacity.

[0065] E1 < E2 ··· (Equation 1)

[0066] FIG. 5A is a graph showing the relationship between temperature and hydrogen release amount for the hydrogen storage material 1 of the embodiment. FIG. 5B is a graph showing the relationship between temperature and hydrogen absorption amount for the hydrogen storage material 1 of the embodiment.

[0067] In FIGS. 5A and 5B, the sample of Example 1 is an example (example) of the hydrogen storage material 1 of the present embodiment, and the metal-supported powder 20 is supported on the metal body powder 10 under the conditions shown below. In the sample of Example 1, the binding energy E1 between the metal body element, which is a component of the metal body powder 10, and the hydrogen atom, and the binding energy E2 between the metal body element, which is a component of the metal body powder 10, and the metal-supported element of the metal-supported powder 20 satisfy the relationship shown in the above (Equation 1). On the other hand, the sample of Example C1 is the same as that of Example 1 except that the metal-supported powder 20 is not supported on the metal body powder 10, and the hydrogen storage material is composed of the metal body powder 10. These samples are both Mg that have absorbed sufficient hydrogen. ·Metal body powder 10: Metal Mg powder (average particle size: 10μm) Metal-supported powder 20: Metallic Ni powder (average particle size: 100 nm) Support ratio: The amount of Ni added was 10 atomic %. The effect was also confirmed at 5% addition.

[0068] In FIG. 5A, the dashed line indicates the results when no activation treatment was performed on the sample of each example, and the solid line indicates the results when the activation treatment was performed on the sample of each example.

[0069] 5A, hydrogen is released in Example 1 at a lower temperature than in Example C1. This result confirms that the hydrogen storage material 1 of Example 1, in which the metal-supported powder 20, which is a metal Ni powder, is supported on the metal body powder 10, which is a metal Mg powder, can release hydrogen at a lower temperature than the hydrogen storage material of Example C1, in which the metal-supported powder 20, which is a metal Ni powder, is not supported.

[0070] 5A, in Example 1, the results when no activation treatment was performed (dashed line) are similar to the results when activation treatment was performed (solid line). In contrast, in Example C1, hydrogen is released at a lower temperature when activation treatment was performed (solid line) than when activation treatment was not performed (dashed line). This result confirms that the hydrogen storage material 1 of Example 1, in which metal-supported powder 20, which is metal Ni powder, is supported on metal body powder 10, which is metal Mg powder, can be used without the activation treatment, compared to the hydrogen storage material of Example C1, in which metal-supported powder 20, which is metal Ni powder, is not supported.

[0071] 5B, Example 1 has a higher hydrogen storage capacity in a lower temperature range than Example C1. This confirms that the hydrogen storage material 1 of Example 1, in which the metal-supported powder 20, which is a metal Ni powder, is supported on the metal body powder 10, which is a metal Mg powder, has excellent hydrogen storage capacity.

[0072] <Other> Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0073] 10: Metal body powder, 10a: Metal body element, 20: Metal support powder, 20a: Metal support element, 30a: Hydrogen atom

Claims

1. a metal body powder containing a metal body element as a component; a metal-supported powder containing a metal-supported element other than the metal main element as a component and supported on the metal main powder; wherein the metal body powder is at least one of a metal Mg powder containing Mg as the metal body element and a metal Li powder containing Li as the metal body element. A hydrogen storage material, The bond energy E1 between the metal main element and a hydrogen atom and the bond energy E2 between the metal main element and the metal supporting element are configured to have the relationship shown in the following (Equation 1). Hydrogen storage materials. E1<E2...(Formula 1)

2. The metal body powder and the metal-supported powder include a metal-bonded portion. The hydrogen storage material according to claim 1 .

3. In the metal-supported powder, the metal-supported element is Ni. The hydrogen storage material according to claim 1 .

4. In the metal-supported powder, the metal-supporting element is Co. The hydrogen storage material according to claim 1 .

5. In the metal-supported powder, the metal-supporting element is Cu. The hydrogen storage material according to claim 1 .

6. The average particle diameter of the metal-supported powder is 100 nm or less. The hydrogen storage material according to claim 1 .

7. The average particle size of the metal body powder is 10 μm or less. The hydrogen storage material according to claim 1 .

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