A porous titanium-iron-zirconium-based hydrogen storage alloy block and a preparation method thereof

Abstract

The present application relates to a kind of porous titanium iron zirconium base hydrogen storage alloy block and its preparation method, wherein alloy block is the alloy block capable of cyclic hydrogen absorption and hydrogen release at room temperature, the inside and surface of the alloy block are uniformly distributed with porosity and fresh surface that hydrogen absorption is not hindered;The alloy block includes Zr3Fe phase and TiFe phase;The porosity includes three-dimensional communication hole and isolated closed pore, and the isolated closed pore accounts for 1.0%~5.0% of the total pore volume ratio;The porosity of the alloy block is 10%~50%.The present application adopts one-step sintering method, process is simple, low in cost, solve the problem of uneven composition in smelting method, and after forming sintering neck between powder in sintering process, part of hole can be surrounded.Meanwhile, give full play to the dual role of chloride pore-forming agent and deoxidizer, spontaneously deoxidize and form porous structure in sintering process, and the hydrogen absorption and hydrogen release kinetics performance of alloy block is improved in coordination with Zr3Fe in situ generated in material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen storage alloy, and particularly relates to a porous titanium-iron-zirconium-based hydrogen storage alloy block and a preparation method thereof. BACKGROUND

[0002] Hydrogen storage alloy is a safe and efficient hydrogen storage method, which can exhibit good cycle capacity under certain temperature and hydrogen pressure conditions by using the reversible interaction between hydrogen and metal atoms. Common hydrogen storage alloys mainly include rare earth series, magnesium series, titanium series, etc., wherein the titanium-based hydrogen storage alloy has the advantages of abundant raw material reserves and mild hydrogen absorption and desorption conditions, and is one of the best choices for fixed hydrogen storage applications.

[0003] However, the preparation of the traditional titanium-iron-based hydrogen storage alloy mainly adopts the methods of smelting and crushing, and a small amount of research on powder metallurgy process. The titanium-iron-based hydrogen storage alloy prepared by the former method often has problems such as composition segregation, and needs to be treated for a long time. Moreover, due to the high affinity of titanium-iron alloy to oxygen, the oxidation layer on the surface will hinder the hydrogen absorption process. Therefore, promoting activation by surface modification, mechanical ball milling and large plastic deformation is an effective way to improve the hydrogen absorption kinetics, but the strain and other defects introduced by plastic deformation will cause obvious hydrogen absorption and desorption hysteresis and poor cycle stability.

[0004] Although the powder metallurgy process is an effective way to solve the segregation of high melting point elements in the smelting process. However, the oxygen content of the hydrogen storage alloy prepared by this method is much higher than the oxygen content requirement of pure titanium in industry, and high-temperature activation is required to occur hydrogen absorption reaction. SUMMARY

[0005] The present application aims to overcome the shortcomings of the prior art, and provides a porous titanium-iron-zirconium-based hydrogen storage alloy block and a preparation method thereof without activation and short preparation process.

[0006] The porous titanium-iron-zirconium-based hydrogen storage alloy block of the present application is an alloy block capable of cyclic hydrogen absorption and desorption at room temperature, and the inside and surface of the alloy block are uniformly distributed with pores and fresh surfaces that are not hindered by hydrogen absorption.

[0007] The alloy block comprises Zr3Fe phase and TiFe phase.

[0008] The pores comprise three-dimensional interconnected pores and isolated closed pores, and the isolated closed pores account for 1.0 % to 5.0 % of the total pore volume ratio. The porosity of the alloy block is 10 % to 50 %.

[0009] Porosity refers to the proportion of the volume occupied by pores (including pores, defects, etc.) in the material. Among them, the three-dimensional interconnected pores are formed by the connection of isolated closed pores during the removal of pore-forming agents, and are also affected by factors such as phase interface and oxygen-containing gaseous product removal.

[0010] The porosity of the alloy block and the proportion of isolated closed pores therein need to be appropriate. If the porosity is less than 10%, the generation rate of fresh surface will slow down when the lattice expansion caused by the solid-solved hydrogen atoms, and the hydrogen transport in the block will be affected. On the contrary, when the porosity is too high, the oxidation risk will increase, and the strength will be relatively reduced, which is not conducive to the accurate control of the hole type. In addition, the material is easy to pulverize during the hydrogen absorption and release cycle, and the cycle stability is reduced.

[0011] Further, in the porous titanium-iron-zirconium-based hydrogen storage alloy block of the present application, the Zr3Fe phase is uniformly distributed, and the proportion of the Zr3Fe phase in the alloy block is 5-30wt.%. The Zr3Fe phase as the second phase that absorbs hydrogen before the TiFe phase, when the content of the Zr3Fe phase is too small, the lattice expansion after hydrogen absorption is not obvious, and the fewer second phases will also limit the number of phase interfaces. That is, the addition of Zr powder does not play an obvious role. The Zr3Fe phase binds with hydrogen more strongly than the TiFe phase, so when the mass ratio of the Zr3Fe phase in the material is higher than 30wt.%, it will cause incomplete hydrogen release, and the high brittleness of Zr will accelerate the crushing and pulverization of the hydrogen storage alloy.

[0012] Further, in the porous titanium-iron-zirconium-based hydrogen storage alloy block of the present application, the oxygen content of the alloy block is 1500-4500 ppm, and the oxygen content of the fresh surface is less than or equal to 1500 ppm.

[0013] Further, in the porous titanium-iron-zirconium-based hydrogen storage alloy block of the present application, the alloy block has a first hydrogen absorption incubation period of 0-30 min, and a hydrogen absorption amount of >1.8 wt.%,

[0014] And the hydrogen absorption amount of the alloy block after 10 cycles of hydrogen absorption and release is >1.6 wt.%.

[0015] Further, in the porous titanium-iron-zirconium-based hydrogen storage alloy block of the present application, the alloy block is an alloy block that does not contain rare earth elements, vanadium elements, aluminum elements, manganese elements and chromium elements. The use of rare earth elements will increase the preparation cost of the hydrogen storage alloy in the present application. Vanadium powder is toxic, and the increase of vanadium will increase the hydrogen release reaction enthalpy. The addition of manganese will increase the hydrogen absorption and release hysteresis of the alloy, increase the platform slope, and increase the platform pressure.

[0016] In another aspect, the present application also provides a preparation method of the porous titanium-iron-zirconium-based hydrogen storage alloy block as described above, comprising the following steps:

[0017] 1) mixing titanium powder, iron powder, zirconium powder, and chloride in an inert atmosphere to obtain a mixed powder, and controlling the oxygen content of the mixed powder to be 3500-7000 ppm; the oxygen content of the mixed powder is too high, which will adversely affect the hydrogen storage performance, but reducing the oxygen content of the mixed powder is often limited by the cost and the specific preparation process. The oxygen content of the mixed powder is 3500-7000 ppm, which is the appropriate oxygen content range allowed by the present application under the action of the second phase and the pore-forming agent.

[0018] 2) pressing the mixed powder in an inert atmosphere to obtain a titanium-iron-zirconium-based hydrogen storage alloy blank;

[0019] 3) sintering the titanium-iron-zirconium-based hydrogen storage alloy blank in an inert atmosphere at a sintering temperature of 900-1200℃ for 2-5 h to obtain a hydrogen storage alloy block;

[0020] 4) placing the hydrogen storage alloy block in a high-purity hydrogen environment for 0-30 min under a hydrogen pressure of 2-6 MPa to obtain the alloy block as described above, which can be used cyclically at room temperature and has a fresh surface uniformly distributed.

[0021] The sintering temperature in step 3) is selected according to the phase diagram of TiFe alloy. If the sintering time is too long, the risk of oxidation will be greatly increased; on the contrary, if the sintering time is too short, it is difficult to ensure the full homogenization of the alloy.

[0022] The system pressure of 2-6 MPa hydrogen causes the second phase to expand after absorbing hydrogen, which cooperates with the stress concentration around the pores and edges to cause fracture and generate fresh surfaces, and the hydrogen absorption rate is rapidly increased. The hydrogen pressure is directly related to the plateau pressure of the hydrogen storage alloy. Lower plateau pressure will weaken the kinetic performance of the hydrogen storage alloy. Too high hydrogen pressure cannot take advantage of the system that can absorb hydrogen under medium and low hydrogen pressure.

[0023] Further, the rotation speed of the mixing in step 1) of the preparation method is 20-100 r / min, and the mixing time is 30-180 min.

[0024] Further, the chloride in step 1) of the preparation method is any one or a combination of zirconium chloride and iron chloride; the mass percentage of the chloride in the mixed powder is 0.25-2.5; the atomic ratio of iron to titanium in the mixed powder is 0.8-1.0, and the stoichiometric ratio of zirconium in the mixed powder is 0.025-0.15.

[0025] Titanium and iron elements constitute the main phase of the hydrogen storage alloy, and the component ratio is determined according to a phase diagram; insufficient or excessive addition of titanium and iron elements will cause the formation of by-products of non-main phase TiFe.

[0026] Excessive addition of zirconium will increase the brittleness of the material; the combination of zirconium and hydrogen is higher than that of titanium, and high addition of zirconium will cause difficulties in the hydrogen release process.

[0027] Insufficient addition of chlorides will weaken the oxygen removal effect and the pore forming effect; excessive addition of chlorides will cause excessively high porosity, unstable structure and increased oxidation risk.

[0028] Further, in step 1) of the preparation method, the powder particle size of the titanium powder, the iron powder and the zirconium powder is 100-300 mesh; the chlorides are in powder form, and the particle size of the chlorides is 100-200 mesh.

[0029] If the particle size of the titanium powder, the iron powder and the zirconium powder as raw material powder is too large, it is not conducive to alloying; if the particle size of the raw material powder is too small, the specific surface area is large, and it is difficult to ensure the low oxygen condition of the raw material powder. Under the condition that the addition amount of chlorides is constant, with the increase of the particle size of the chloride crystal, the number is correspondingly reduced, which increases the non-uniformity of the distribution of the chloride particles, causing uneven distribution of pores. If the size of the chlorides is too small, the generated pore edges are thick, which is not conducive to the fracture of the pore edges in the subsequent hydrogen absorption process; at the same time, the small-sized pore-forming agent makes the metal powder combine more closely during the alloying process of the green body, which further reduces the porosity of the material. The above reasons will reduce the generation rate of fresh surface and hinder the hydrogen absorption reaction.

[0030] Further, in step 2) of the preparation method, the pressure of the pressing forming is 70-200 MPa, and the pressure holding time is 3-10 min.

[0031] The pressure range of the pressing forming needs to be appropriate, on the basis of ensuring that the powder can be formed into a green body, the contact between the titanium powders is improved as much as possible, and the bonding force between the titanium powders is improved. The stress release during sintering promotes the sintering process, but excessive pressing pressure is not conducive to the removal process of the pore-forming agent, but easy to cause local collapse, and also reduces the opening rate of the pores. Therefore, the process parameters of the pressing forming also need to be matched with the pore-forming agent, and the two have a synergistic effect.

[0032] The beneficial effects of the present application are as follows:

[0033] The porous titanium-iron-zirconium based hydrogen storage alloy of this invention introduces zirconium to form a composite structure of Zr3Fe and TiFe phases with appropriate content (5~30 wt.%) and uniform distribution, synergistically regulating hydrogen storage performance. The Zr3Fe phase, as a highly active second phase, preferentially absorbs hydrogen, inducing lattice expansion and generating stress concentration at the phase interface. This promotes the synergistic effect of three-dimensional interconnected pores and isolated closed pores (accounting for 1.0%~5.0%), exposing a fresh surface with oxygen content ≤1500 ppm, significantly reducing the initial hydrogen absorption incubation period to within 30 minutes, and eliminating the need for high-temperature activation. The optimized porosity of 10%~50% accelerates hydrogen transport, alleviates lattice expansion stress during hydrogen absorption, and avoids the risks of oxidation and pulverization caused by excessive porosity. This enables the alloy bulk to achieve a high hydrogen absorption capacity of >1.8 wt.% at room temperature and maintain a reversible cycling performance of >1.6 wt.% after 10 cycles, solving the problems of difficult activation, poor kinetics, and short cycle life of traditional titanium-iron based alloys.

[0034] On the other hand, this invention uses chlorides (such as zirconium chloride / iron) as pore-forming agents and deoxidizers, combined with low-temperature mixing (oxygen content 3500~7000 ppm) and atmospheric pressure sintering (900~1200℃), to simultaneously achieve alloy homogenization and pore structure control in an inert atmosphere. The gaseous products generated by chloride decomposition effectively remove oxygen impurities, controlling the bulk oxygen content at 1500~4500 ppm, significantly lower than the conventional levels of powder metallurgy processes. Through the synergistic design of pressing pressure (70~200 MPa) and pore-forming agent particle size (100~200 mesh), a multi-level pore structure with moderate pore thickness is formed. Combined with short-time hydrogen pressure treatment (2~6 MPa, ≤30 minutes), the active surface is further exposed by utilizing the hydrogen-induced fracture effect. This process simplifies traditional smelting and crushing or complex powder metallurgy processes, avoids the addition of high-cost rare earth elements and toxic vanadium, and takes into account the advantages of high efficiency, environmental protection and low cost.

[0035] This invention achieves rapid hydrogen absorption and desorption at room temperature and long cycle life for hydrogen storage alloy blocks through synergistic innovation in composition, structure, and process, while also possessing high mechanical strength and resistance to pulverization. The design, free of rare earth elements, vanadium, and manganese, reduces raw material costs and toxicity risks, making it suitable for stationary hydrogen storage systems. The porous structure endows the material with excellent heat / mass transfer properties, meeting the dual requirements of industrial applications for hydrogen storage density (>1.8 wt.%) and cycle stability (>1.6 wt.%) after 10 cycles, providing an efficient and reliable technical solution for the large-scale application of titanium-iron-based hydrogen storage alloys. Attached Figure Description

[0036] Figure 1 XRD analysis of the porous titanium-iron-zirconium based hydrogen storage alloy block of the present invention;

[0037] Figure 2This is a morphological image of the hydrogen storage alloy block after atmospheric pressure sintering according to the present invention;

[0038] Figure 3 This is a microscopic morphology diagram of the hydrogen storage alloy block after atmospheric pressure sintering according to the present invention;

[0039] Figure 4 These are microscopic morphology images and surface scan images of the hydrogen storage alloy block after hydrogen absorption and desorption cycles as described in this invention.

[0040] Figure 5 for Figure 4 Enlarged image;

[0041] Figure 6 The results are CT test results of the hydrogen storage alloy block described in this invention, where (a) is the CT scan result, (b) is the reconstructed image of the sample in the selected area, (c) is the three-dimensional image of the isolated closed hole, and (d) is the three-dimensional image of the three-dimensional interconnected hole. Detailed Implementation

[0042] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments are now described in detail with reference to the accompanying drawings. The described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the detailed embodiments, conventional conditions or conditions provided by the manufacturer shall apply.

[0043] In the following description, when referring to the accompanying drawings, the same numbers in different drawings denote the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure.

[0044] The present invention will be further described in detail below with reference to specific embodiments. Specific implementation method one:

[0046] A porous titanium-iron-zirconium-based hydrogen storage alloy block, wherein the porous titanium-iron-zirconium-based hydrogen storage alloy block is an alloy block capable of cyclically absorbing and releasing hydrogen at room temperature, and the interior and surface of the alloy block are uniformly distributed with pores and a fresh surface that allows unimpeded hydrogen absorption.

[0047] The alloy bulk comprises Zr3Fe phase and TiFe phase;

[0048] The pores include three-dimensional interconnected pores and isolated closed pores, and the isolated closed pores account for 1.0% to 5.0% of the total pore volume; the porosity of the alloy block is 10% to 50%.

[0049] In other embodiments, the Zr3Fe phase is uniformly distributed, and the Zr3Fe phase accounts for 5 to 30 wt.% of the total alloy bulk.

[0050] In other embodiments, the oxygen content of the alloy block is 1500~4500 ppm, and the oxygen content of the fresh surface is less than or equal to 1500 ppm.

[0051] In other embodiments, the initial hydrogen absorption incubation period of the alloy block is 0-30 min, and the hydrogen absorption amount of the alloy block is >1.8 wt.%.

[0052] Furthermore, after 10 cycles of hydrogen absorption and release, the hydrogen absorption amount of the alloy block is >1.6 wt.%.

[0053] In other embodiments, the alloy block is an alloy block that does not contain rare earth elements, vanadium elements, aluminum elements, manganese elements, and chromium elements. Specific Implementation Method Two:

[0055] A method for preparing a porous titanium-iron-zirconium-based hydrogen storage alloy block according to any of the above embodiments includes the following steps:

[0056] 1) According to the raw material ratio, titanium powder, iron powder, zirconium powder and chloride are mixed in an inert atmosphere to obtain a mixed powder, and the oxygen content of the mixed powder is controlled to be 3500~7000 ppm.

[0057] 2) The mixed powder is pressed into shape in an inert atmosphere to obtain a titanium-iron-zirconium based hydrogen storage alloy billet;

[0058] 3) The titanium-iron-zirconium based hydrogen storage alloy billet is sintered under inert gas protection at a temperature of 900~1200 ℃ for 2~5 h to obtain hydrogen storage alloy block.

[0059] 4) Place the hydrogen storage alloy block in a high-purity hydrogen environment for 0~30 min at a hydrogen pressure of 2~6 MPa to obtain the porous titanium-iron-zirconium based hydrogen storage alloy block.

[0060] In other embodiments, the mixing speed in step 1) is 20~100 r / min, and the mixing time is 30~180 min.

[0061] In other embodiments, the chloride in step 1) is any one or a combination of two of zirconium chloride and ferric chloride; the mass percentage of chloride in the mixed powder is 0.25 to 2.5; the atomic ratio of iron to titanium in the mixed powder is 0.8 to 1.0; and the stoichiometric ratio of zirconium in the mixed powder is 0.025 to 0.15.

[0062] In other embodiments, the particle size of the titanium powder, iron powder and zirconium powder in step 1) is 100~300 mesh; the chloride is in powder form and the particle size of the chloride is 100~200 mesh.

[0063] In other embodiments, the pressing pressure in step 2) is 70~200 MPa, and the holding time is 3~10 min. Example 1:

[0064] 1) According to the raw material ratio, titanium powder, iron powder, zirconium powder and chloride are mixed in an inert atmosphere to obtain a mixed powder, and the oxygen content of the mixed powder is controlled to be 3500ppm; the mixing speed is 20~100 r / min and the mixing time is 30~180min.

[0065] In this Example 1, the chloride is any one or a combination of two of zirconium chloride and ferric chloride; the mass percentage of chloride in the mixed powder is 0.25; the atomic ratio of iron to titanium in the mixed powder is 0.8~1.0; and the stoichiometric ratio of zirconium in the mixed powder is 0.025.

[0066] The titanium powder, iron powder, and zirconium powder have a particle size of 100-300 mesh; the chloride is in powder form, and the chloride has a particle size of 100-200 mesh.

[0067] 2) The mixed powder is loaded into a hydraulic mold under inert gas protection and pressed in an inert atmosphere to obtain a titanium-iron-zirconium based hydrogen storage alloy billet; the pressing pressure is 70~200 MPa and the holding time is 3~10 min.

[0068] 3) The titanium-iron-zirconium based hydrogen storage alloy billet is sintered under inert gas protection at a temperature of 900~1200 ℃ for 2~5 h to obtain hydrogen storage alloy block.

[0069] 4) Place the hydrogen storage alloy block in a high-purity hydrogen (≥99.999%) environment for 0~30 min at a hydrogen pressure of 2~6 MPa to obtain the porous titanium-iron-zirconium based hydrogen storage alloy block.

[0070] The porous titanium-iron-zirconium based hydrogen storage alloy block is an alloy block capable of cyclically absorbing and releasing hydrogen at room temperature.

[0071] likeFigures 1-6 As shown, the alloy block has uniformly distributed pores and fresh surfaces that allow for unimpeded hydrogen absorption both internally and on its surface; the oxygen content of the alloy block is 3000~4000 ppm, and the oxygen content of the fresh surfaces is less than or equal to 1500 ppm. The alloy block does not contain rare earth elements, vanadium, aluminum, manganese, or chromium. The alloy block only includes Zr3Fe and TiFe phases; the Zr3Fe phase is uniformly distributed, and its proportion within the alloy block is 5~8 wt.%. The pores include three-dimensional interconnected pores and isolated closed pores, with the isolated closed pores accounting for 1.0%~3.0% of the total pore volume; the porosity of the alloy block is 10%~15%. Example 2:

[0072] The only difference between Example 2 and Example 1 is that the mass percentage of chloride in the mixed powder is 0.5%. Example 3:

[0073] The only difference between Example 3 and Example 1 is that the mass percentage of chloride in the mixed powder is 1%. Example 4:

[0074] The only difference between Example 4 and Example 1 is that the mass percentage of chloride in the mixed powder is 2%. Example 5:

[0075] The only difference between Example 5 and Example 1 is that the mass percentage of chloride in the mixed powder is 2.5%. Example 6:

[0076] The only difference between Example 6 and Example 3 is that the stoichiometric ratio of zirconium in the mixed powder is 0.1. Example 7:

[0077] The only difference between Example 7 and Example 3 is that the stoichiometric ratio of zirconium in the mixed powder is 0.15. Example 8:

[0078] The only difference between Example 8 and Example 6 is that in step 1), the mixed powder is obtained by mixing the materials, and the oxygen content of the mixed powder is controlled to be 5000 ppm. Example 9:

[0079] The only difference between Example 9 and Example 6 is that in step 1), the mixed powder is obtained by mixing the materials, and the oxygen content of the mixed powder is controlled to be 7000 ppm.

[0080] Comparative Example 1:

[0081] The only difference between Comparative Example 1 and Example 1 is that the mixed powder does not contain chloride.

[0082] Comparative Example 2:

[0083] The only difference between Comparative Example 2 and Example 1 is that the mass percentage of chloride in the mixed powder is 3%.

[0084] Comparative Example 3:

[0085] The only difference between Comparative Example 3 and Example 6 is that the mixed powder does not contain zirconium.

[0086] Comparative Example 4:

[0087] The only difference between Comparative Example 4 and Example 6 is that the stoichiometric ratio of zirconium in the mixed powder is 0.2.

[0088] Comparative Example 5:

[0089] The only difference between Comparative Example 5 and Example 6 is that in step 1), the mixed powder is obtained by mixing the materials, and the oxygen content of the mixture is controlled to be 8000 ppm.

[0090] .

[0091] This invention has been described through the specific embodiments described above. Those skilled in the art should understand that various modifications and equivalent substitutions can be made to this invention without departing from its scope. Parts not described in detail in this specification are well-known to those skilled in the art. Furthermore, various modifications can be made to this invention for specific situations or circumstances without departing from its scope. Therefore, this invention is not limited to the specific embodiments disclosed, but should include all embodiments falling within the scope of the claims.

Claims

1. A porous titanium-iron-zirconium based hydrogen storage alloy block, characterized in that, The porous titanium-iron-zirconium based hydrogen storage alloy block is an alloy block that can cyclically absorb and release hydrogen at room temperature. The interior and surface of the alloy block are uniformly distributed with pores and a fresh surface that allows for unimpeded hydrogen absorption. The alloy bulk comprises Zr3Fe phase and TiFe phase; The pores include three-dimensional interconnected pores and isolated closed pores, and the isolated closed pores account for 1.0% to 5.0% of the total pore volume; the porosity of the alloy block is 10% to 50%. The method for preparing the porous titanium-iron-zirconium-based hydrogen storage alloy bulk material includes the following steps: 1) According to the raw material ratio, titanium powder, iron powder, zirconium powder and chloride are mixed in an inert atmosphere to obtain a mixed powder, and the oxygen content of the mixed powder is controlled to be 3500~7000 ppm. 2) The mixed powder is pressed into shape in an inert atmosphere to obtain a titanium-iron-zirconium based hydrogen storage alloy billet; 3) The titanium-iron-zirconium based hydrogen storage alloy billet is sintered under an inert atmosphere at a temperature of 900~1200 ℃ for 2~5 h to obtain a hydrogen storage alloy block. 4) Place the hydrogen storage alloy block in a hydrogen environment for 0-30 minutes at a hydrogen pressure of 2-6 MPa to obtain the porous titanium-iron-zirconium based hydrogen storage alloy block. Furthermore, the chloride mentioned in step 1) is any one or a combination of two of zirconium chloride and ferric chloride; the mass percentage of chloride in the mixed powder is 0.25~2.5; the atomic ratio of iron to titanium in the mixed powder is 0.8~1.0; and the stoichiometric ratio of zirconium in the mixed powder is 0.025~0.

15.

2. The porous titanium-iron-zirconium based hydrogen storage alloy block according to claim 1, characterized in that, The Zr3Fe phase is uniformly distributed, and the Zr3Fe phase accounts for 5~30 wt.% of the total alloy bulk.

3. The porous titanium-iron-zirconium based hydrogen storage alloy block according to claim 1, characterized in that, The oxygen content of the alloy block is 1500~4500 ppm, and the oxygen content of the fresh surface is less than or equal to 1500 ppm.

4. The porous titanium-iron-zirconium based hydrogen storage alloy block according to claim 1, characterized in that, The initial hydrogen absorption incubation period of the alloy block is 0-30 min, and the hydrogen absorption capacity of the alloy block is >1.8 wt.%. Furthermore, after 10 cycles of hydrogen absorption and release, the hydrogen absorption amount of the alloy block is >1.6 wt.%.

5. The porous titanium-iron-zirconium based hydrogen storage alloy block according to claim 1, characterized in that, The alloy block is an alloy block that does not contain rare earth elements, vanadium elements, aluminum elements, manganese elements, and chromium elements.

6. A method for preparing a porous titanium-iron-zirconium based hydrogen storage alloy block according to any one of claims 1 to 5, characterized in that, Includes the following steps: 1) According to the raw material ratio, titanium powder, iron powder, zirconium powder and chloride are mixed in an inert atmosphere to obtain a mixed powder, and the oxygen content of the mixed powder is controlled to be 3500~7000 ppm. 2) The mixed powder is pressed into shape in an inert atmosphere to obtain a titanium-iron-zirconium based hydrogen storage alloy billet; 3) The titanium-iron-zirconium based hydrogen storage alloy billet is sintered under an inert atmosphere at a temperature of 900~1200 ℃ for 2~5 h to obtain a hydrogen storage alloy block. 4) Place the hydrogen storage alloy block in a hydrogen environment for 0-30 minutes at a hydrogen pressure of 2-6 MPa to obtain the porous titanium-iron-zirconium based hydrogen storage alloy block as described in any one of claims 1-5. Furthermore, the chloride mentioned in step 1) is any one or a combination of two of zirconium chloride and ferric chloride; the mass percentage of chloride in the mixed powder is 0.25~2.5; the atomic ratio of iron to titanium in the mixed powder is 0.8~1.0; and the stoichiometric ratio of zirconium in the mixed powder is 0.025~0.

15.

7. The preparation method according to claim 6, characterized in that, In step 1), the mixing speed is 20~100 r / min and the mixing time is 30~180 min.

8. The preparation method according to claim 6, characterized in that, In step 1), the particle size of titanium powder, iron powder and zirconium powder is 100~300 mesh; the chloride is in powder form and the particle size of the chloride is 100~200 mesh.

9. The preparation method according to claim 6, characterized in that, In step 2), the pressing pressure is 70~200 MPa, and the holding time is 3~10 min.

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