Porous titanium-iron-zirconium-based hydrogen storage alloy block and preparation method thereof

Abstract

The invention relates to a porous titanium-iron-zirconium-based hydrogen storage alloy block and a preparation method thereof, the alloy block is an alloy block capable of circularly absorbing and releasing hydrogen at normal temperature, and pores and fresh surfaces without hindering hydrogen absorption are uniformly distributed inside and on the surface of the alloy block; the alloy block body comprises a Zr3Fe phase and a TiFe phase; the pores comprise three-dimensional communicating pores and isolated closed pores, and the isolated closed pores account for 1.0%-5.0% of the volume of the whole pores; and the porosity of the alloy block body is 10%-50%. A one-step sintering method is adopted, the process is simple and convenient, the cost is low, the problem that components are not uniform in a smelting method is solved, and part of holes can be defined after sintering necks are formed among powder in the sintering process. And meanwhile, the dual effects of a chloride pore-forming agent and a deoxidizing agent are fully exerted, spontaneous deoxidation is performed in the sintering process, a porous structure is formed, and the hydrogen absorption and desorption dynamic performance of an alloy block is improved through cooperation with Zr3Fe generated in situ in the material.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen storage alloys, and particularly relates to a porous titanium-iron-zirconium-based hydrogen storage alloy bulk and a preparation method thereof. Background Art

[0002] Hydrogen storage alloys are a safe and efficient way to store hydrogen. Under certain temperature and hydrogen pressure conditions, they can utilize the reversible interaction between hydrogen and metal atoms and exhibit good cycling performance. Common hydrogen storage alloys mainly include rare earth-based, magnesium-based, titanium-based, etc. Among them, titanium-based hydrogen storage alloys have the advantages of rich raw material reserves and mild hydrogen absorption and desorption conditions, and are one of the best choices for stationary hydrogen storage applications.

[0003] However, the preparation of traditional titanium-iron-based hydrogen storage alloys mainly uses melting and crushing methods, and there is also a small amount of research on powder metallurgy processes. The titanium-iron-based hydrogen storage alloys prepared by the former often have problems such as composition segregation and require long-term homogenization treatment. Moreover, due to the high affinity of titanium-iron alloys for oxygen, the oxide layer on their surface will hinder the hydrogen absorption process. Therefore, promoting activation through methods such as surface modification, mechanical ball milling, and severe plastic deformation is an effective way to improve the hydrogen absorption kinetic performance, but defects such as strain introduced by plastic deformation will also cause obvious hydrogen absorption and desorption hysteresis and poor cycling stability.

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

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a porous titanium-iron-zirconium-based hydrogen storage alloy bulk and a preparation method thereof that do not require activation and have a short preparation process.

[0006] A porous titanium-iron-zirconium-based hydrogen storage alloy bulk of the present invention, the porous titanium-iron-zirconium-based hydrogen storage alloy bulk is an alloy bulk capable of cyclic hydrogen absorption and desorption at room temperature, and pores and fresh surfaces that are not hindered in hydrogen absorption are uniformly distributed inside and on the surface of the alloy bulk; The alloy bulk includes Zr3Fe phase and TiFe phase; The pores include three-dimensional connected pores and isolated closed pores, and the isolated closed pores account for 1.0% - 5.0% of the total pore volume; the porosity of the alloy bulk is 10% - 50%.

[0007] Porosity refers to the proportion of the volume occupied by pores (including air holes, defects, etc.) in the material. Among them, the three-dimensional connected pores are formed by the connection of isolated closed pores during the removal of the pore-forming agent, and are also affected by factors such as phase interfaces and the removal of oxygen-containing gaseous products.

[0008] The porosity of the alloy block and the proportion of isolated closed pores therein should be appropriate. If the porosity is less than 10%, when the hydrogen atoms in solid solution cause lattice expansion, the generation rate of fresh surfaces will slow down, and it will affect the transport of hydrogen in the block. On the contrary, when the porosity is too high, it will increase the oxidation risk and cause a relative reduction in strength, which is not conducive to the precise control of pore shape. In addition, during the hydrogen absorption and desorption cycle process, the material is also prone to pulverization, and the cycle stability is reduced.

[0009] Furthermore, in the porous titanium-iron-zirconium-based hydrogen storage alloy block of the present invention, the Zr3Fe phase is uniformly distributed, and the proportion of the Zr3Fe phase in the alloy block is 5-30 wt.%. The Zr3Fe phase, as the second phase that undergoes hydrogen absorption reaction prior to the TiFe phase, when the content of the Zr3Fe phase is too small, the lattice expansion after hydrogen absorption caused can be not obvious, and the small amount of the second phase will also limit the number of phase interfaces. That is, the addition of Zr powder does not play an obvious role. The combination of Zr3Fe with hydrogen is stronger than that of TiFe with hydrogen. Therefore, when the mass ratio of the Zr3Fe phase in the material is higher than 30 wt.%, it will cause incomplete hydrogen desorption, and Zr is brittle, and a higher Zr3Fe phase will accelerate the fragmentation and pulverization of the hydrogen storage alloy.

[0010] Furthermore, in the porous titanium-iron-zirconium-based hydrogen storage alloy block of the present invention, the oxygen content of the alloy block is 1500-4500 ppm, and the oxygen content of the fresh surface should be less than or equal to 1500 ppm.

[0011] Furthermore, in the porous titanium-iron-zirconium-based hydrogen storage alloy block of the present invention, the alloy block has an initial hydrogen absorption incubation period of 0-30 min and a hydrogen absorption amount > 1.8 wt.%, and after 10 cycles of hydrogen absorption and desorption of the alloy block, the hydrogen absorption amount > 1.6 wt.%.

[0012] Furthermore, in the porous titanium-iron-zirconium-based hydrogen storage alloy block of the present invention, 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 invention. Vanadium powder is toxic, and the increase of vanadium will increase the enthalpy change of the hydrogen desorption reaction. The addition of manganese will increase the hydrogen absorption and desorption hysteresis of the alloy, increase the platform slope, and increase the platform pressure.

[0013] On the other hand, the present invention also provides a preparation method based on the porous titanium-iron-zirconium-based hydrogen storage alloy block described in any one of the above, including the following steps: 1) Mix titanium powder, iron powder, zirconium powder, and chlorides in an inert atmosphere to obtain a mixed powder, and control the oxygen content of the mixed powder to be 3500 - 7000 ppm. If the oxygen content of the mixed powder is too high, it will have an adverse effect on the hydrogen storage performance. However, reducing the oxygen content of the mixed powder is often limited by cost and specific preparation processes. The oxygen content of 3500 - 7000 ppm of the mixed powder is the appropriate oxygen content range allowed by the present invention under the action of the second phase and the pore-forming agent.

[0014] 2) Press the mixed powder in an inert atmosphere to form a titanium-iron-zirconium-based hydrogen storage alloy green body. 3) Sinter the titanium-iron-zirconium-based hydrogen storage alloy green body under normal pressure in an inert atmosphere protection. The sintering temperature is 900 - 1200 °C, and the sintering time is 2 - 5 h to obtain a hydrogen storage alloy block. 4) Place the hydrogen storage alloy block in a high-purity hydrogen environment for 0 - 30 min, and the hydrogen pressure is 2 - 6 MPa to obtain the alloy block that can be recycled at room temperature and has a fresh surface evenly distributed as described above.

[0015] The setting of the sintering temperature in step 3) is specifically selected according to the phase diagram of the TiFe alloy. If the sintering time is too long, the risk of oxidation will be greatly increased; conversely, if the sintering time is too short, it is difficult to ensure the full homogenization of the alloy.

[0016] For the system pressure of 2 - 6 MPa hydrogen, after the second phase absorbs hydrogen and expands, it cooperates with the stress concentration around the pore edges and pores to cause fracture, generating a fresh surface, and the hydrogen absorption rate increases rapidly. The hydrogen pressure is directly related to the plateau pressure of the hydrogen storage alloy. A lower plateau pressure will weaken the kinetic performance of the hydrogen storage alloy. If the hydrogen pressure is too high, the advantage that this system can absorb hydrogen under medium and low hydrogen pressure conditions cannot be exerted.

[0017] Furthermore, in step 1) of the preparation method of the present invention, the rotation speed of the mixing is 20 - 100 r / min, and the mixing time is 30 - 180 min.

[0018] Furthermore, in step 1) of the preparation method of the present invention, the chloride is any one or a combination of two 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.

[0019] Titanium and iron elements constitute the main phase of the hydrogen storage alloy, and their composition ratio is determined according to the phase diagram. Insufficient or excessive addition of titanium and iron elements will cause the formation of by-products of non-main phase TiFe.

[0020] Excessive addition of zirconium will increase the brittleness of the material; the combination of zirconium and hydrogen is higher than that of titanium, and a high addition amount of zirconium will cause difficulties in the hydrogen release process.

[0021] Insufficient addition of chloride will weaken the deoxidation effect and pore-forming effect. Excessive addition of chloride will result in too high porosity, unstable structure and increased oxidation risk.

[0022] Furthermore, in step 1) of the preparation method of the present invention, the powder particle sizes of the titanium powder, iron powder and zirconium powder are 100 - 300 mesh; the chloride is in powder form, and the particle size of the chloride is 100 - 200 mesh.

[0023] As raw material powders, if the particle sizes of the titanium powder, iron powder and zirconium powder are too large, it is not conducive to alloying; if the particle sizes of the raw material powders are too small, the specific surface area is relatively large, and it is difficult to ensure the low-oxygen condition of the raw material powders. When the addition amount of the chloride is constant, as the crystal particle size of the chloride increases, the quantity decreases correspondingly, increasing the non-uniformity of the chloride particle distribution and causing non-uniform pore distribution. If the size of the chloride is too small, the pore edges produced are thicker, which is not conducive to the fracture of the pore edges during the subsequent hydrogen absorption process; at the same time, the pore-forming agent with too small size makes the metal powders combine more tightly during the pressing of the green body and the alloying of the green body, resulting in a further decrease in the porosity of the material. All the above reasons will reduce the generation rate of fresh surfaces and hinder the progress of the hydrogen absorption reaction.

[0024] Furthermore, in step 2) of the preparation method of the present invention, the pressure for pressing and forming is 70 - 200 MPa, and the pressure holding time is 3 - 10 min.

[0025] The pressure range for pressing and forming needs to be appropriate. On the basis of ensuring that the powder can be formed into a green body, it is necessary to improve the contact between titanium powders as much as possible and increase the bonding force between titanium powders. The stress release during sintering promotes the sintering process, but too high pressing pressure is not conducive to the removal process of the pore-forming agent, and it is easy to cause local collapse, and at the same time, it will also reduce the opening rate of pores. Therefore, the process parameters for pressing and forming also need to be matched with the pore-forming agent, and the two have a synergistic effect.

[0026] The beneficial effects of the present invention: The porous titanium-iron-zirconium-based hydrogen storage alloy bulk of the present invention forms a composite structure of Zr3Fe phase with a suitable content (5-30 wt.%) and uniform distribution and TiFe phase by introducing zirconium element, and synergistically regulates the hydrogen storage performance. As a highly active second phase, the Zr3Fe phase preferentially absorbs hydrogen and causes lattice expansion, generating stress concentration at the phase interface, promoting the synergistic effect of three-dimensional connected pores and isolated closed pores (accounting for 1.0%-5.0%), exposing a fresh surface with an oxygen content ≤ 1500 ppm, significantly reducing the initial hydrogen absorption incubation period to within 30 minutes, and no high-temperature activation is required. The optimized porosity of 10%-50% can not only accelerate hydrogen transport and relieve the stress of hydrogen absorption lattice expansion, but also avoid the risks of oxidation and pulverization caused by excessive pores, enabling the alloy bulk to achieve a high hydrogen storage capacity of > 1.8 wt.% at room temperature and maintain a reversible cycle 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.

[0027] On the other hand, the present invention uses chlorides (such as zirconium / iron chloride) as pore formers and deoxidizers, combines low-temperature mixing (oxygen content 3500-7000 ppm) and atmospheric pressure sintering process (900-1200 °C) to synchronously realize alloy homogenization and pore structure regulation in an inert atmosphere. The gaseous products generated by the decomposition of chlorides effectively remove oxygen impurities, controlling the oxygen content of the bulk within 1500-4500 ppm, significantly lower than the conventional level of powder metallurgy process. Through the synergistic design of pressing pressure (70-200 MPa) and pore former particle size (100-200 mesh), a multi-level pore structure with moderate pore edge thickness is formed, combined with short-term hydrogen pressure treatment (2-6 MPa, ≤ 30 minutes), and the hydrogen-induced fracture effect is used to further expose the active surface. This process simplifies the traditional melting and crushing or complex powder metallurgy process, 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.

[0028] Through the synergistic innovation of composition-structure-process, the present invention realizes the rapid hydrogen absorption and release and long cycle life of the hydrogen storage alloy bulk at room temperature, while having high mechanical strength and anti-pulverization ability. The design without elements such as rare earth, vanadium and manganese reduces the raw material cost and toxicity risk, and is suitable for fixed hydrogen storage systems. The porous structure endows the material with good heat / mass transfer characteristics, meeting the dual requirements of industrial application for hydrogen storage density (> 1.8 wt.%) and cycle stability (> 1.6 wt.% after 10 times), providing an efficient and reliable technical solution for the large-scale application of titanium-iron-based hydrogen storage alloys. Brief Description of the Drawings

[0029] Figure 1 XRD analysis of the porous titanium-iron-zirconium-based hydrogen storage alloy bulk described in the present invention; Figure 2Morphology diagram of the hydrogen storage alloy block after atmospheric pressure sintering according to the present invention; Figure 3 Microscopic morphology diagram of the hydrogen storage alloy block after atmospheric pressure sintering according to the present invention; Figure 4 Microscopic morphology diagram and surface scan diagram of the alloy block after hydrogen absorption and desorption cycling of the hydrogen storage alloy block according to the present invention; Figure 5 is Figure 4 magnified view of; Figure 6 CT test results of the hydrogen storage alloy block according to the present invention, where (a) is the CT scan result, (b) is the reconstructed image of the selected area sample, (c) is the three-dimensional diagram of the isolated closed pores, and (d) is the three-dimensional diagram of the three-dimensional connected pores. Specific embodiments

[0030] In order to more clearly understand the technical features, objectives, and effects of the present invention, the specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention. Those not specified in the specific embodiments are carried out according to conventional conditions or conditions provided by the manufacturer.

[0031] When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. The terms used in the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0032] The present invention will be further described in detail below with specific embodiments. Specific embodiment one:

[0033] A porous titanium-iron-zirconium-based hydrogen storage alloy block, the porous titanium-iron-zirconium-based hydrogen storage alloy block being an alloy block capable of cyclically absorbing and desorbing hydrogen at room temperature, with pores and a fresh surface that is unobstructed for hydrogen absorption evenly distributed inside and on the surface of the alloy block; The alloy block includes a Zr3Fe phase and a TiFe phase; The pores include three-dimensional connected pores and isolated closed pores, and the isolated closed pores account for 1.0% - 5.0% of the total pore volume; the porosity of the alloy block is 10% - 50%.

[0034] In other embodiments, the Zr3Fe phase is uniformly distributed, and the proportion of the Zr3Fe phase in the alloy bulk is 5-30 wt.%.

[0035] In other embodiments, the oxygen content of the alloy bulk is 1500-4500 ppm, and the oxygen content of the fresh surface is less than or equal to 1500 ppm.

[0036] In other embodiments, the initial hydrogen absorption incubation period of the alloy bulk is 0-30 min, the hydrogen absorption amount of the alloy bulk > 1.8 wt.%, and after 10 cycles of hydrogen absorption and desorption of the alloy bulk, the hydrogen absorption amount > 1.6 wt.%.

[0037] In other embodiments, the alloy bulk is an alloy bulk that does not contain rare earth elements, vanadium elements, aluminum elements, manganese elements, and chromium elements. Specific Embodiment 2:

[0038] A preparation method of a porous titanium-iron-zirconium-based hydrogen storage alloy bulk based on any one of the above embodiments, comprising the following steps: 1) According to the raw material ratio, mix titanium powder, iron powder, zirconium powder, and chloride in an inert atmosphere to obtain a mixed powder, and control the oxygen content of the mixed powder to be 3500-7000 ppm; 2) Press the mixed powder into a shape in an inert atmosphere to obtain a titanium-iron-zirconium-based hydrogen storage alloy blank; 3) Sinter the titanium-iron-zirconium-based hydrogen storage alloy blank under the protection of an inert gas, the sintering temperature is 900-1200 °C, and the sintering time is 2-5 h to obtain a hydrogen storage alloy block; 4) Place the hydrogen storage alloy block in a high-purity hydrogen environment for 0-30 min, and the hydrogen pressure is 2-6 MPa to obtain the porous titanium-iron-zirconium-based hydrogen storage alloy bulk.

[0039] In other embodiments, the rotation speed of the mixing in step 1) is 20-100 r / min, and the mixing time is 30-180 min.

[0040] In other embodiments, the chloride in step 1) is any one or a combination of two 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.

[0041] In other embodiments, the powder particle sizes of the titanium powder, iron powder, and zirconium powder in step 1) are 100-300 mesh; the chloride is in powder form, and the particle size of the chloride is 100-200 mesh.

[0042] In other embodiments, the pressure for press forming in step 2) is 70 - 200 MPa, and the pressure holding time is 3 - 10 min. Example 1:

[0043] 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 ppm; the mixing speed is 20 - 100 r / min, and the mixing time is 30 - 180 min.

[0044] In this Example 1, the chloride is any one or a combination of two of zirconium chloride and iron chloride; the mass percentage of the 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.

[0045] The powder particle sizes of the titanium powder, iron powder, and zirconium powder are 100 - 300 mesh; the chloride is in powder form, and the particle size of the chloride is 100 - 200 mesh.

[0046] 2) The mixed powder is loaded into a hydraulic mold under the protection of an inert gas and press formed in an inert atmosphere to obtain a titanium - iron - zirconium - based hydrogen storage alloy green body; the pressure for press forming is 70 - 200 MPa, and the pressure holding time is 3 - 10 min.

[0047] 3) The titanium - iron - zirconium - based hydrogen storage alloy green body is sintered under the protection of an inert gas, the sintering temperature is 900 - 1200 °C, and the sintering time is 2 - 5 h to obtain a hydrogen storage alloy block; 4) The hydrogen storage alloy block is placed in an environment of high - purity hydrogen (≥99.999%) for 0 - 30 min, and the hydrogen pressure is 2 - 6 MPa to obtain the porous titanium - iron - zirconium - based hydrogen storage alloy block body.

[0048] The porous titanium - iron - zirconium - based hydrogen storage alloy block body is an alloy block body capable of cyclic hydrogen absorption and desorption at room temperature.

[0049] Such as Figures 1-6As shown, pores and fresh surfaces with unhindered hydrogen absorption are evenly distributed inside and on the surface of the alloy block; the oxygen content of the alloy block is 3000 - 4000 ppm, and the oxygen content of the fresh surface should be less than or equal to 1500 ppm. The alloy block does not contain rare earth elements, vanadium elements, aluminum elements, manganese elements, and chromium elements. The alloy block only includes Zr3Fe phase and TiFe phase; the Zr3Fe phase is evenly distributed, and the proportion of the Zr3Fe phase in the alloy block is 5 - 8 wt.%. The pores include three-dimensional connected pores and isolated closed pores, and the proportion of the isolated closed pores in the total pore volume is 1.0% - 3.0%; the porosity of the alloy block is 10% - 15%. Example 2:

[0050] The difference between this Example 2 and Example 1 is only that the mass percentage of chloride in the mixed powder is 0.5. Example 3:

[0051] The difference between this Example 3 and Example 1 is only that the mass percentage of chloride in the mixed powder is 1. Example 4:

[0052] The difference between this Example 4 and Example 1 is only that the mass percentage of chloride in the mixed powder is 2. Example 5:

[0053] The difference between this Example 5 and Example 1 is only that the mass percentage of chloride in the mixed powder is 2.5. Example 6:

[0054] The difference between this Example 6 and Example 3 is only that the stoichiometric ratio of zirconium in the mixed powder is 0.1. Example 7:

[0055] The difference between this Example 7 and Example 3 is only that the stoichiometric ratio of zirconium in the mixed powder is 0.15. Example 8:

[0056] The difference between this Example 8 and Example 6 is only that in step 1), the mixed powder is obtained by mixing, and the oxygen content of the mixed powder is controlled to be 5000 ppm. Example 9:

[0057] The difference between this Example 9 and Example 6 is only that in step 1), the mixed powder is obtained by mixing, and the oxygen content of the mixed powder is controlled to be 7000 ppm.

[0058] Comparative Example 1: The difference between Comparative Example 1 and Example 1 is only that: the mixed powder does not contain chlorides.

[0059] Comparative Example 2: The difference between Comparative Example 2 and Example 1 is only that the mass percentage of chlorides in the mixed powder is 3%.

[0060] Comparative Example 3: The difference between Comparative Example 3 and Example 6 is only that: the mixed powder does not contain zirconium.

[0061] Comparative Example 4: The difference between Comparative Example 4 and Example 6 is only that the stoichiometric ratio of zirconium in the mixed powder is 0.2.

[0062] Comparative Example 5: The difference between Comparative Example 5 and Example 6 is only that in step 1), when the mixed powder is obtained by mixing, the oxygen content of the mixture is controlled to be 8000 ppm.

[0063] 。

[0064] The present invention is illustrated by the above specific embodiments. Those skilled in the art should understand that various transformations and equivalent substitutions can be made to the present invention without departing from the scope of the present invention. The parts not detailed in the specification of the present invention are well-known technologies to those skilled in the art. Additionally, various modifications can be made to the present invention for specific situations or circumstances without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed, but should include all embodiments falling within the scope of the claims of the present invention.

Claims

1. A porous titanium-iron-zirconium-based hydrogen storage alloy bulk, characterized in that, The porous titanium-iron-zirconium-based hydrogen storage alloy bulk is an alloy bulk capable of cyclic hydrogen absorption and desorption at room temperature. Pores and fresh surfaces where hydrogen absorption is unhindered are uniformly distributed inside and on the surface of the alloy bulk. The alloy bulk includes 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% - 5.0% of the total pore volume; the porosity of the alloy bulk is 10% - 50%.

2. The porous titanium-iron-zirconium-based hydrogen storage alloy bulk according to claim 1, wherein The Zr3Fe phase is uniformly distributed, and the proportion of the Zr3Fe phase in the alloy bulk is 5 - 30 wt.%.

3. The porous titanium-iron-zirconium-based hydrogen storage alloy bulk according to claim 1, characterized in that, The oxygen content of the alloy bulk 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 bulk according to claim 1, characterized in that, The initial hydrogen absorption incubation period of the alloy bulk is 0 - 30 min, the hydrogen absorption amount of the alloy bulk > 1.8 wt.%, and after 10 cycles of hydrogen absorption and desorption of the alloy bulk, the hydrogen absorption amount > 1.6 wt.%.

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

6. A preparation method of a porous titanium-iron-zirconium-based hydrogen storage alloy block according to any one of claims 1 to 5, characterized in that, It includes the following steps: 1) According to the raw material ratio, mix titanium powder, iron powder, zirconium powder, and chloride in an inert atmosphere to obtain a mixed powder, and control the oxygen content of the mixed powder to be 3500 - 7000 ppm; 2) Press the mixed powder into a shape in an inert atmosphere to obtain a titanium-iron-zirconium-based hydrogen storage alloy green body; 3) Sinter the titanium-iron-zirconium-based hydrogen storage alloy green body under the protection of an inert atmosphere, the sintering temperature is 900 - 1200 °C, and the sintering time is 2 - 5 h to obtain a hydrogen storage alloy bulk; 4) Place the hydrogen storage alloy bulk in a hydrogen environment for 0 - 30 min, and the hydrogen pressure is 2 - 6 MPa to obtain the porous titanium-iron-zirconium-based hydrogen storage alloy bulk according to any one of claims 1 - 5.

7. The preparation method according to claim 6, characterized in that, In the step 1), the rotation speed of the mixing 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 the step 1), the chloride is any one or a combination of two 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.

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

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

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