A rare earth AB2 type hydrogen storage alloy and a preparation method and application thereof

Abstract

This invention relates to a rare earth AB2 type hydrogen storage alloy, its preparation method, and its application. The preparation method of the rare earth AB2 type hydrogen storage alloy includes the following steps: (1) refining the rare earth components with the Cr and / or VFe components in the Ti-Zr-Cr-Mn-VFe raw material to obtain an alloy ingot; (2) after surface treatment, the alloy ingot obtained in step (1) is smelted with the remaining components in the Ti-Zr-Cr-Mn-VFe raw material to obtain the rare earth AB2 type hydrogen storage alloy. This invention refines the Cr and / or VFe components with rare earth elements to improve their purity, and then uses the refined alloy as raw material for smelting, thereby achieving the purpose of reducing the impurity content of the alloy and improving the hydrogen storage performance.

Description

Technical Field

[0001] This invention relates to the field of solid-state hydrogen storage technology, specifically to a rare-earth AB2 type hydrogen storage alloy, its preparation method, and its application. Background Technology

[0002] With social development and population growth, human demand for energy is gradually increasing, and the excessive consumption of fossil fuels has caused serious environmental pollution problems. To achieve sustainable development, the search for new clean energy sources has become a key focus for the energy industry. Hydrogen energy, as a high-energy-density and abundant clean energy source, holds promise as a substitute for fossil fuels to solve energy shortages and environmental pollution problems. Currently, the development of hydrogen energy mainly focuses on hydrogen fuel cell vehicles and hydrogen energy storage. Solid-state hydrogen storage technology, as one of the important means of hydrogen energy storage, has advantages such as high hydrogen storage density and good safety, and has attracted much attention from researchers.

[0003] Solid-state hydrogen storage technology refers to storing hydrogen in solid materials through physical or chemical adsorption, chemical reaction, etc. Among them, AB2 type hydrogen storage alloy is a common solid-state hydrogen storage material with low cost, high hydrogen storage capacity and cycle stability, and is widely used in the field of hydrogen energy. AB2 type hydrogen storage alloy is mainly based on two categories: Ti-based and Zr-based, and is considered to be the second generation of solid-state hydrogen storage alloy with high energy density. For example, CN115377433A discloses a method for preparing a high-performance AB2 type hydrogen storage alloy, including the following steps: (1) mixing and melting the various metal raw materials that make up the AB2 type hydrogen storage alloy to obtain an alloy ingot; (2) crushing the alloy ingot and preparing alloy sheets by strip melting; (3) mixing graphene with the alloy sheets and then high-energy ball milling to obtain the AB2 type hydrogen storage alloy; wherein the various metal raw materials of the hydrogen storage alloy are two or three of Ti, Cr and Mn; the linear speed of strip melting is 5-20 m / s; the speed of high-energy ball milling is 600-900 r / min.

[0004] However, the hydrogen storage performance of AB2-type hydrogen storage alloys is greatly affected by the purity of the raw materials. The alloy is typically smelted using raw materials such as titanium, chromium, manganese, and ferrovanadium alloys. These raw materials have low purity, with chromium and ferrovanadium being the most problematic, containing large amounts of impurities such as Al, Si, C, S, and P. The inclusion of these impurities will reduce the hydrogen storage performance and cycle stability of the hydrogen storage alloy.

[0005] CN117286378A discloses a TiMnV-based hydrogen storage alloy, its preparation method, and its applications. The chemical composition of the alloy is Ti. a Mn b V x Fe y Zr cThe alloy is prepared using a combination of vacuum aluminothermic melting, vacuum arc melting, and vacuum induction melting. The alloy exhibits high homogeneity and low impurity content. However, the use of high-purity raw materials results in higher product costs, hindering mass production. The mass percentages are: 25 ≤ a ≤ 28, 50 ≤ b ≤ 52.5, 2.5 ≤ c < 4, 12 ≤ x ≤ 16, 2 ≤ y ≤ 4.5, x + y + c ≤ 22.5, x / y ≥ 4.5, and a + b + c + x + y = 100.

[0006] Therefore, in view of the shortcomings of the existing technology, there is an urgent need to provide a method for preparing hydrogen storage alloys with low impurity content, good hydrogen storage performance and suitable for mass production. Summary of the Invention

[0007] The purpose of this invention is to provide a rare earth AB2 type hydrogen storage alloy, its preparation method and application. By refining the Cr and / or VFe components to improve their purity, and then using the refined alloy as raw material for smelting, the purpose of reducing the impurity content of the alloy and improving the hydrogen storage performance is achieved.

[0008] To achieve this objective, the present invention employs the following technical solution:

[0009] In a first aspect, the present invention provides a method for preparing a rare earth AB2 type hydrogen storage alloy, the method comprising the following steps:

[0010] (1) The rare earth components are refined with the Cr and / or VFe components in the Ti-Zr-Cr-Mn-VFe raw material to obtain alloy ingots;

[0011] (2) After surface treatment, the alloy ingot obtained in step (1) is smelted with the remaining components in the Ti-Zr-Cr-Mn-VFe raw material to obtain the rare earth AB2 type hydrogen storage alloy.

[0012] The present invention provides a method for preparing a rare earth AB2 type hydrogen storage alloy. This method modifies the alloy smelting process by refining the rare earth elements with the Cr and / or VFe components in the Ti-Zr-Cr-Mn-VFe raw material. During refining, the high reactivity of rare earth elements allows them to absorb oxygen from the raw material, forming rare earth oxides. The high melting point of these oxides causes impurities to accumulate around them during smelting, or to form compounds. After refining, surface treatment removes these impurities, thereby increasing the purity of the Cr and / or VFe components. Further smelting with the remaining components yields a rare earth AB2 type hydrogen storage alloy with higher purity and effective hydrogen absorption capacity, significantly improving the alloy's hydrogen absorption / desorption performance and cycle performance. This preparation method is low-cost and simple, making it suitable for large-scale production.

[0013] Preferably, the general formula for the composition of the Cr and / or VFe components and the rare earth components in step (1) is A. m B n Where m ranges from 1 to 2, and n ranges from 0.01 to 0.03; A represents Cr and / or VFe, and B includes any one or at least two combinations of La, Ce, Pr, or Y.

[0014] The value of m is in the range of 1-2, for example, it can be 1, 1.2, 1.5, 1.8 or 2, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0015] The value of n is in the range of 0.01-0.03, for example, it can be 0.01, 0.02 or 0.03, but it is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0016] The B includes any one or at least two of La, Ce, Pr or Y. Typical but non-limiting combinations include the combination of La and Ce, the combination of Ce, Pr and Y, or the combination of La, Ce, Pr and Y.

[0017] Preferably, the refining process in step (1) is carried out in a vacuum electric arc furnace.

[0018] Preferably, the vacuum level of the vacuum arc furnace before the refining process in step (1) is ≤5×10⁻⁶. -3 Pa, for example, could be 5 × 10 -3 Pa, 4×10 -3 Pa, 3×10 -3 Pa, 2×10 -3 Pa or 1×10 -3 Pa, but not limited to the listed values, applies to other unlisted values ​​within the range as well.

[0019] Preferably, the refining process in step (1) is carried out under the protection of an inert gas.

[0020] Preferably, the current for the refining process in step (1) is 80-200A, for example, it can be 80A, 100A, 120A, 150A or 200A, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0021] Preferably, the refining process in step (1) takes 80-300 seconds per cycle, for example, 80 seconds per cycle, 120 seconds per cycle, 200 seconds per cycle, 250 seconds per cycle or 300 seconds per cycle, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0022] Preferably, the refining process in step (1) is performed 3-5 times, for example, 3 times, 4 times or 5 times.

[0023] Preferably, the surface treatment in step (2) includes mechanical polishing and / or chemical reagent treatment.

[0024] Preferably, the endpoint of the surface treatment in step (2) is to remove oxides and impurities from the surface of the alloy ingot.

[0025] Preferably, the smelting process in step (2) is carried out in an induction melting furnace.

[0026] Preferably, the vacuum degree of the smelting process in step (2) is ≤5×10 -3 Pa, for example, could be 5 × 10 -3 Pa, 4×10 -3 Pa, 3×10 -3 Pa, 2×10 -3 Pa or 1×10 -3 Pa, but not limited to the listed values, applies to other unlisted values ​​within the range as well.

[0027] Preferably, the melting process in step (2) is to continue melting for 1.5-2.5 minutes after all components have melted. For example, it can be 1.5 minutes, 1.8 minutes, 2 minutes, 2.2 minutes or 2.5 minutes, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0028] Preferably, the power supply for the smelting process in step (2) is 18-22kW, for example, it can be 18kW, 19kW, 20kW, 21kW or 22kW, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0029] The parameters of the induction melting furnace, such as the vacuum degree, time, and power supply, of the melting process described in this invention can be varied according to the adjustment of the production capacity.

[0030] As a preferred embodiment of the preparation method of the present invention, the preparation method includes the following steps:

[0031] (1) The rare earth components and the Cr and / or VFe components in the Ti-Zr-Cr-Mn-VFe raw material are refined in a vacuum arc furnace under inert gas protection. The current is 80-200A, the time is 80-300s / cycle, and the number of cycles is 3-5, to obtain an alloy ingot; before the refining process, the vacuum degree of the vacuum arc furnace is ≤5×10 -3 Pa;

[0032] The general formula for the composition of the Cr and / or VFe components and the rare earth components is A. m B n Where m ranges from 1 to 2, and n ranges from 0.01 to 0.03; A represents Cr and / or VFe, and B includes any one or at least two combinations of La, Ce, Pr, or Y.

[0033] (2) The alloy ingot obtained in step (1) is surface treated to remove oxides and impurities from the surface of the alloy ingot. Then, it is smelted with the remaining components in the Ti-Zr-Cr-Mn-VFe raw material in an induction melting furnace with a vacuum degree ≤5×10 - 3 Pa, the time is 1.5-2.5 min after all components have melted, the power supply is 18-22 kW, and the rare earth AB2 type hydrogen storage alloy is obtained.

[0034] Secondly, the present invention provides a rare earth AB2 type hydrogen storage alloy, which is prepared by the preparation method of the rare earth AB2 type hydrogen storage alloy described in the first aspect.

[0035] The rare earth AB2 type hydrogen storage alloy prepared by this invention has significantly improved effective hydrogen absorption capacity and hydrogen absorption / desorption cycle stability compared with conventional methods. Its maximum hydrogen absorption capacity increased from 1.89 wt% to 1.96 wt% compared with the direct smelting method. After 300 hydrogen absorption / desorption cycle stability tests, its cycle efficiency increased from 96.9% to 98.6%. It can better meet the usage requirements of solid-state hydrogen storage devices and fuel cells, and has high application value.

[0036] Preferably, the rare earth AB2 type hydrogen storage alloy has the general formula Ti. a Zr b Cr c Mn d (VFe) f Where a ranges from 0.6 to 0.9, b ranges from 0.1 to 0.4, c ranges from 0.5 to 1.2, d ranges from 0.8 to 1.5, and f ranges from 0.01 to 0.1.

[0037] The value of 'a' is in the range of 0.6-0.9, for example, it can be 0.6, 0.7, 0.8 or 0.9, but it is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0038] The value of b is in the range of 0.1-0.4, for example, it can be 0.1, 0.2, 0.3 or 0.4, but it is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0039] The value of c ranges from 0.5 to 1.2, for example, it can be 0.5, 0.6, 0.8, 1 or 1.2, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0040] The value of d is in the range of 0.8-1.5, for example, it can be 0.8, 1, 1.2 or 1.5, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0041] The value of f is in the range of 0.01-0.1, for example, it can be 0.01, 0.02, 0.05, 0.08 or 0.1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0042] Thirdly, the present invention provides an application of the rare earth AB2 type hydrogen storage alloy as described in the second aspect, wherein the rare earth AB2 type hydrogen storage alloy is used in solid-state hydrogen energy storage systems or hydrogen metallurgy.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The present invention provides a method for preparing a rare earth AB2 type hydrogen storage alloy. This method modifies the alloy smelting process by refining rare earth elements with the Cr and / or VFe components in the Ti-Zr-Cr-Mn-VFe raw material. During refining, the high reactivity of rare earth elements allows them to absorb oxygen from the raw material, forming rare earth oxides. The high melting point of these oxides causes impurities to accumulate around them during smelting, or to form compounds. After refining, surface treatment removes these impurities, thereby increasing the purity of the Cr and / or VFe components. Further smelting with the remaining components yields a rare earth AB2 type hydrogen storage alloy with higher purity and effective hydrogen absorption capacity. This significantly improves the alloy's hydrogen absorption and desorption performance and cycle performance. The maximum hydrogen absorption capacity increases from 1.89 wt% to 1.96 wt% compared to the direct smelting method. After 300 hydrogen absorption and desorption cycle stability tests, the cycle efficiency increases from 96.9% to 98.6%. This preparation method has the advantages of low cost and simple process, making it suitable for large-scale preparation. Detailed Implementation

[0045] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0046] Example 1

[0047] This embodiment provides a rare earth AB2 type hydrogen storage alloy, the general formula of which is Ti. 0.6 Zr 0.4 Cr 0.8 Mn1.2 (VFe) 0.02 The preparation method of the rare earth AB2 type hydrogen storage alloy includes the following steps:

[0048] (1) CrLa 0.03 (VFe)La 0.03 The refining process was carried out under argon protection in a vacuum arc furnace at a current of 150A, a time of 120s per cycle, and a total of 4 cycles, to obtain an alloy ingot. Prior to the refining process, the vacuum arc furnace was evacuated to a vacuum level of 5 × 10⁻⁶. -3 Pa;

[0049] (2) The alloy ingot obtained in step (1) is mechanically ground to remove oxides and impurities from its surface. Then, it is smelted with the remaining components in the Ti-Zr-Cr-Mn-VFe raw material in an induction melting furnace at a vacuum degree of 5×10⁻⁶. - 3 Pa, the melting time is 2 minutes after all components have melted, and the power supply is 20 kW, to obtain the rare earth AB2 type hydrogen storage alloy.

[0050] Example 2

[0051] This embodiment provides a rare earth AB2 type hydrogen storage alloy, the general formula of which is Ti. 0.6 Zr 0.4 Cr 0.8 Mn 1.2 (VFe) 0.02 The preparation method of the rare earth AB2 type hydrogen storage alloy includes the following steps:

[0052] (1) CrLa 0.03 (VFe)La 0.03 The refining process was carried out under argon protection in a vacuum arc furnace at a current of 80A, a time of 300s per cycle, and for a total of 3 cycles, to obtain an alloy ingot. Prior to the refining process, the vacuum furnace was evacuated to a vacuum level of 4×10⁻⁶. -3 Pa;

[0053] (2) The alloy ingot obtained in step (1) is mechanically ground to remove oxides and impurities from its surface. Then, it is smelted with the remaining components in the Ti-Zr-Cr-Mn-VFe raw material in an induction melting furnace at a vacuum degree of 4×10⁻⁶. - 3 Pa, the melting time is 1.5 min after all components have melted, the power supply is 18 kW, and the rare earth AB2 type hydrogen storage alloy is obtained.

[0054] Example 3

[0055] This embodiment provides a rare earth AB2 type hydrogen storage alloy, the general formula of which is Ti. 0.6 Zr 0.4 Cr 0.8 Mn 1.2 (VFe) 0.02 The preparation method of the rare earth AB2 type hydrogen storage alloy includes the following steps:

[0056] (1) CrLa 0.03 (VFe)La 0.03 The refining process was carried out under argon protection in a vacuum arc furnace at a current of 200A, a time of 80s per cycle, and a total of 5 cycles, to obtain an alloy ingot. Prior to the refining process, the vacuum furnace was evacuated to a vacuum level of 3×10⁻⁶. -3 Pa;

[0057] (2) The alloy ingot obtained in step (1) is treated with a 0.1 mol / L hydrochloric acid solution to remove oxides and impurities from the surface of the alloy ingot. Then, it is smelted with the remaining components in the Ti-Zr-Cr-Mn-VFe raw material in an induction melting furnace with a vacuum degree of 3×10⁻⁶. -3 Pa, the melting time is 2.5 min after all components have melted, the power supply is 22 kW, and the rare earth AB2 type hydrogen storage alloy is obtained.

[0058] Example 4

[0059] This embodiment provides a rare earth AB2 type hydrogen storage alloy. The difference between the preparation method of the rare earth AB2 type hydrogen storage alloy and that of Embodiment 1 is that, except for the CrLa mentioned in step (1), 0.03 (VFe)La 0.03 Adjusted to a single CrLa 0.03 Except for the above, everything else is the same as in Example 1.

[0060] Example 5

[0061] This embodiment provides a rare earth AB2 type hydrogen storage alloy. The difference between the preparation method of the rare earth AB2 type hydrogen storage alloy and that of Embodiment 1 is that, except for the CrLa mentioned in step (1), 0.03 (VFe)La 0.03 Adjusted to a single (VFe)La 0.03 Except for the above, everything else is the same as in Example 1.

[0062] Example 6

[0063] This embodiment provides a rare earth AB2 type hydrogen storage alloy. The difference between the preparation method of the rare earth AB2 type hydrogen storage alloy and that of Embodiment 1 is that, except for the CrLa mentioned in step (1), 0.03(VFe)La 0.03 Adjusted to CrCe 0.03 (VFe)Ce 0.03 Except for the above, everything else is the same as in Example 1.

[0064] Example 7

[0065] This embodiment provides a rare earth AB2 type hydrogen storage alloy. The difference between the preparation method of the rare earth AB2 type hydrogen storage alloy and that of Embodiment 1 is that, except for the CrLa mentioned in step (1), 0.03 (VFe)La 0.03 Adjusted to a single CrCe 0.03 Except for the above, everything else is the same as in Example 1.

[0066] Example 8

[0067] This embodiment provides a rare earth AB2 type hydrogen storage alloy. The difference between the preparation method of the rare earth AB2 type hydrogen storage alloy and that of Embodiment 1 is that, except for the CrLa mentioned in step (1), 0.03 (VFe)La 0.03 Adjusted to a single (VFe)Ce 0.03 Except for the above, everything else is the same as in Example 1.

[0068] Example 9

[0069] This embodiment provides a rare earth AB2 type hydrogen storage alloy. The difference between the preparation method of the rare earth AB2 type hydrogen storage alloy and that of Embodiment 1 is that, except for the CrLa mentioned in step (1), 0.03 (VFe)La 0.03 Adjusted to CrLa 0.01 (VFe)La 0.01 Except for the above, everything else is the same as in Example 1.

[0070] Example 10

[0071] This embodiment provides a rare earth AB2 type hydrogen storage alloy. The difference between the preparation method of the rare earth AB2 type hydrogen storage alloy and that of Embodiment 1 is that, except for the CrLa mentioned in step (1), 0.03 (VFe)La 0.03 Adjusted to a single CrLa 0.01 Except for the above, everything else is the same as in Example 1.

[0072] Example 11

[0073] This embodiment provides a rare earth AB2 type hydrogen storage alloy. The difference between the preparation method of the rare earth AB2 type hydrogen storage alloy and that of Embodiment 1 is that, except for the CrLa mentioned in step (1), 0.03 (VFe)La 0.03Adjusted to a single (VFe)La 0.01 Except for the above, everything else is the same as in Example 1.

[0074] Example 12

[0075] This embodiment provides a rare earth AB2 type hydrogen storage alloy. The difference between the preparation method of the rare earth AB2 type hydrogen storage alloy and that of Embodiment 1 is that, except for the CrLa mentioned in step (1), 0.03 (VFe)La 0.03 Adjusted to CrCe 0.01 (VFe)Ce 0.01 Except for the above, everything else is the same as in Example 1.

[0076] Example 13

[0077] This embodiment provides a rare earth AB2 type hydrogen storage alloy. The difference between the preparation method of the rare earth AB2 type hydrogen storage alloy and that of Embodiment 1 is that, except for the CrLa mentioned in step (1), 0.03 (VFe)La 0.03 Adjusted to a single CrCe 0.01 Except for the above, everything else is the same as in Example 1.

[0078] Example 14

[0079] This embodiment provides a rare earth AB2 type hydrogen storage alloy. The difference between the preparation method of the rare earth AB2 type hydrogen storage alloy and that of Embodiment 1 is that, except for the CrLa mentioned in step (1), 0.03 (VFe)La 0.03 Adjusted to a single (VFe)Ce 0.01 Except for the above, everything else is the same as in Example 1.

[0080] Comparative Example 1

[0081] This comparative example provides a rare earth AB2 type hydrogen storage alloy. The preparation method of the rare earth AB2 type hydrogen storage alloy differs from that of Example 1 in that the refining treatment described in step (1) is omitted, and the Ti-Zr-Cr-Mn-VFe raw materials are directly smelted. All other aspects are the same as in Example 1.

[0082] The purity of the rare earth AB2 type hydrogen storage alloys provided in Examples 1-14 and Comparative Example 1 was tested using an X-ray fluorescence spectrometer, and the results are shown in Table 1. The hydrogen storage performance was tested using a PCT testing device, and the results are shown in Table 1.

[0083] Table 1

[0084]

[0085]

[0086] As shown in Table 1, the preparation method of the rare earth AB2 type hydrogen storage alloy provided by the present invention can significantly reduce the impurity content of the alloy and improve the hydrogen storage performance. The maximum hydrogen absorption capacity of the smelted rare earth AB2 type hydrogen storage alloy increased from 1.89 wt% to 1.96 wt% compared with the direct smelting method. After 300 hydrogen absorption and desorption cycle stability tests, its cycle efficiency increased from 96.9% to 98.6%, and the hydrogen absorption and desorption capacity and cycle performance were significantly improved.

[0087] The present invention provides a method for preparing a rare earth AB2 type hydrogen storage alloy. This method modifies the alloy smelting process by refining the rare earth elements with the Cr and / or VFe components in the Ti-Zr-Cr-Mn-VFe raw material. During refining, the high reactivity of rare earth elements allows them to absorb oxygen from the raw material, forming rare earth oxides. The high melting point of these oxides causes impurities to accumulate around them during smelting, or to form compounds. After refining, surface treatment removes these impurities, thereby increasing the purity of the Cr and / or VFe components. Further smelting with the remaining components yields a rare earth AB2 type hydrogen storage alloy with higher purity and effective hydrogen absorption capacity, significantly improving the alloy's hydrogen absorption / desorption performance and cycle performance. This preparation method is low-cost and simple, making it suitable for large-scale production.

[0088] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a rare earth AB2 type hydrogen storage alloy, characterized in that, The preparation method includes the following steps: (1) The rare earth components and the Cr and VFe components in the Ti-Zr-Cr-Mn-VFe raw material are refined to obtain alloy ingots; (2) After surface treatment, the alloy ingot obtained in step (1) is smelted with the remaining components in the Ti-Zr-Cr-Mn-VFe raw material to obtain the rare earth AB2 type hydrogen storage alloy. The general formula for the composition of the Cr and VFe components and the rare earth components in step (1) is A. m B n Where m ranges from 1 to 2, and n ranges from 0.01 to 0.03; A represents Cr and VFe, and B includes any one or at least two combinations of La, Ce, Pr, or Y.

2. The preparation method according to claim 1, characterized in that, The refining process described in step (1) is carried out in a vacuum electric arc furnace.

3. The preparation method according to claim 2, characterized in that, Before the refining process in step (1), the vacuum level of the vacuum arc furnace is ≤5×10. -3 Pa.

4. The preparation method according to claim 1, characterized in that, The refining process described in step (1) is carried out under the protection of an inert gas.

5. The preparation method according to claim 1, characterized in that, The current for the refining process in step (1) is 80-200A.

6. The preparation method according to claim 1, characterized in that, The refining process in step (1) takes 80-300 seconds per cycle.

7. The preparation method according to claim 1, characterized in that, The refining process in step (1) is repeated 3-5 times.

8. The preparation method according to claim 1, characterized in that, The surface treatment in step (2) includes mechanical polishing and / or chemical treatment.

9. The preparation method according to claim 1, characterized in that, The endpoint of the surface treatment in step (2) is to remove oxides and impurities from the surface of the alloy ingot.

10. The preparation method according to claim 1, characterized in that, The smelting process described in step (2) is carried out in an induction melting furnace.

11. The preparation method according to claim 1, characterized in that, The vacuum degree of the smelting process in step (2) is ≤5×10 -3 Pa.

12. The preparation method according to claim 1, characterized in that, The melting process in step (2) takes 1.5-2.5 minutes after all components have melted.

13. The preparation method according to claim 1, characterized in that, The power supply for the smelting process in step (2) is 18-22kW.

14. The preparation method according to claim 1, characterized in that, The preparation method includes the following steps: (1) The rare earth components and the Cr and VFe components in the Ti-Zr-Cr-Mn-VFe raw material are refined in a vacuum arc furnace under the protection of an inert gas. The current is 80-200A, the time is 80-300s / cycle, and the number of cycles is 3-5, to obtain an alloy ingot; before the refining process, the vacuum degree of the vacuum arc furnace is ≤5×10 -3 Pa; The general formula for the composition of the Cr and VFe components and the rare earth components is A. m B n Where m ranges from 1 to 2, and n ranges from 0.01 to 0.03; A represents Cr and VFe, and B includes any one or at least two combinations of La, Ce, Pr, or Y. (2) The alloy ingot obtained in step (1) is surface treated to remove oxides and impurities from the surface of the alloy ingot, and then smelted with the remaining components in the Ti-Zr-Cr-Mn-VFe raw material in an induction melting furnace with a vacuum degree ≤5×10 -3 Pa, the time is 1.5-2.5 min after all components have melted, the power supply is 18-22 kW, and the rare earth AB2 type hydrogen storage alloy is obtained.

15. A rare earth AB2 type hydrogen storage alloy, characterized in that, The rare earth AB2 type hydrogen storage alloy is prepared by the preparation method of the rare earth AB2 type hydrogen storage alloy according to any one of claims 1-14.

16. The rare earth AB2 type hydrogen storage alloy according to claim 15, characterized in that, The general formula of the rare earth AB2 type hydrogen storage alloy is Ti. a Zr b Cr c Mn d (VFe) f Where a ranges from 0.6 to 0.9, b ranges from 0.1 to 0.4, c ranges from 0.5 to 1.2, d ranges from 0.8 to 1.5, and f ranges from 0.01 to 0.

1.

17. An application of the rare earth AB2 type hydrogen storage alloy as described in claim 15 or 16, characterized in that, The rare earth AB2 type hydrogen storage alloy is used in solid-state hydrogen energy storage systems or hydrogen metallurgy.

Images