A method for activating deactivated Ti-Mn-based AB2-type hydrogen storage alloy

Abstract

The present application belongs to the field of inorganic metal hydrogen storage material preparation and processing technology, and particularly relates to an activation method of deactivated Ti-Mn-based AB2 type hydrogen storage alloy. The present application co-dopes a small amount of LaNi5 alloy and metal V in the long-stored and deactivated Ti-Mn-based AB2 type hydrogen storage alloy, grinds and mixes, manually press-molds, smelts, and then crushes to obtain a new type of high-performance Ti-Mn-based AB2 type composite hydrogen storage alloy, which can efficiently activate the existing deactivated Ti-Mn-based AB2 type hydrogen storage alloy, restore good initial kinetics and hydrogen storage capacity, and activate a large amount of long-stored and deactivated Ti-Mn-based AB2 type alloy without significantly affecting the cost of the alloy, thereby promoting the wide use of Ti-Mn-based AB2 type alloy in solid-state hydrogen storage devices.

Description

Technical Field

[0001] This invention belongs to the field of inorganic metal hydrogen storage material preparation and processing technology, specifically relating to a method for activating a deactivated Ti-Mn based AB2 type hydrogen storage alloy. Background Technology

[0002] The hydrogen energy industry comprises three key segments: production, storage, transportation, and utilization. Hydrogen gas has a density of only 0.0899 kg / m³ under standard conditions. 3 Hydrogen is difficult to compress and liquefy, and efficient hydrogen storage remains a bottleneck for the large-scale development of the hydrogen energy industry. Currently, the main hydrogen storage methods include high-pressure gaseous, cryogenic liquid, and solid-state hydrogen storage. Compared with high-pressure gaseous and cryogenic liquid hydrogen storage, solid-state hydrogen storage has lower storage pressure and energy consumption, higher safety and volumetric hydrogen storage density, and has good prospects for practical application.

[0003] Solid-state hydrogen storage typically achieves reversible hydrogen absorption and desorption through metallic alloys. Common hydrogen storage alloy types include A2B, AB, AB2, AB5, and vanadium-based BCC solid solutions. Among them, Ti-Mn-based alloys are an important type of AB2 hydrogen storage alloy, characterized by high hydrogen storage capacity (≥1.80 wt.%), fast hydrogen absorption and desorption rates, relatively low absorption and desorption temperatures and pressures (60-120℃, 0.1-1 MPa), low enthalpy change (approximately -37.62 kJ / g H2), and low cost, making them well-suited for practical applications.

[0004] However, Ti-Mn-based AB2 alloys are easily oxidized and prone to surface poisoning upon contact with air, which weakens or even eliminates their hydrogen storage activity. They are typically made to order, on a need-to-use basis, to minimize material transfer or storage time and avoid oxidation deactivation. Even so, solid-state hydrogen storage materials, especially Ti-based materials, are susceptible to oxidation deactivation during transfer and transportation. Even prolonged storage under high-purity inert gas protection will result in slow deactivation. Long-term storage in ordinary packaging further exacerbates the initial kinetics and overall hydrogen absorption capacity of Ti-Mn-based AB2 alloys, eventually leading to complete deactivation. Activation requires repeated hydrogen circulation under high temperature and pressure. The high-temperature and high-pressure alloy activation process is time-consuming and labor-intensive. Furthermore, the activated alloy poses flammable and explosive safety risks and is difficult to pack. Existing solid-state hydrogen storage devices primarily employ a method of encapsulating the alloy within the device before activation. This method is difficult to operate and significantly increases the practical application cost of Ti-Mn-based AB2 alloys, posing a significant challenge to their practical application.

[0005] In conclusion, exploring new technologies for large-scale activation of Ti-Mn-based AB2-type hydrogen storage alloys is an urgent task for promoting the industrial application of solid-state hydrogen storage technology and will be of great significance. Summary of the Invention

[0006] One objective of this invention is to provide a method for activating deactivated Ti-Mn-based AB2-type hydrogen storage alloys. This method is simple, safe, and low-cost, achieving efficient activation of existing deactivated Ti-Mn-based AB2-type hydrogen storage alloys and restoring good initial kinetics and hydrogen storage capacity.

[0007] To achieve the above objectives, the present invention employs the following technical solution: a method for activating a deactivated Ti-Mn-based AB2-type hydrogen storage alloy, comprising the following steps:

[0008] S1. Take deactivated Ti-Mn-based AB2 type hydrogen storage alloy, LaNi5 alloy powder and metallic V powder, grind and mix them in a glove box under protective atmosphere at a mass ratio of (90-100):(1-5):(1-5), and then press them into blocks to obtain bulk materials;

[0009] S2. Place the block material in a vacuum electric arc furnace and melt it at a temperature of 1500-2000℃. After melting, crush it in an Ar-protected glove box to obtain a high-performance Ti-Mn-based AB2 type multiphase hydrogen storage alloy, thus completing the activation process of the deactivated Ti-Mn-based AB2 type hydrogen storage alloy.

[0010] Further improvements to the activation method for deactivated Ti-Mn-based AB2-type hydrogen storage alloys:

[0011] Preferably, the grinding time in step S1 is 5 minutes or more.

[0012] Preferably, the protective atmosphere is one of He, Ar, or N2 gas.

[0013] Preferably, the pressure of the pressure block in step S1 is 10MPa-40MPa.

[0014] Preferably, the block is cylindrical with a diameter of 8mm-40mm and a height of 4mm-30mm.

[0015] Preferably, in step S2, when the block is being melted, after one side is melted and cooled, it is flipped and melted again to ensure that each geometric face of the block is melted at least once, and the melting time for each face is 5-6 minutes.

[0016] Preferably, in step S2, the vacuum degree of the vacuum arc furnace is P0≤10Pa, and the melting time is 5-6min.

[0017] Preferably, the diameter of the particles after the block material is 0.1mm-1mm after melting and crushing in step S2.

[0018] The advantages of this invention compared to the prior art are as follows:

[0019] 1) This invention obtains a novel high-performance Ti-Mn-based AB2-type multiphase hydrogen storage alloy by co-doping a small amount of LaNi5 alloy and metallic V into a long-term deactivated Ti-Mn-based AB2-type hydrogen storage alloy. The second phase in the multiphase alloy is more uniformly distributed. The multiphase alloy has more lattice interstices, providing more channels for hydrogen diffusion and promoting the hydrogen absorption and desorption kinetics of the alloy. After Ni and La separate and are uniformly distributed in the multiphase alloy, more Ni atoms provide a catalytic environment for H2 to dissociate into H atoms on the alloy surface or for H atoms to combine into H2 molecules on the alloy surface, further enhancing the hydrogen absorption and desorption activity. After introducing 10 wt.% LaNi5 and V, the main phase of the TM-LN-V multiphase alloy remains the C14Laves phase of the AB2-type alloy, without affecting the overall crystal structure of the alloy. This method enables the efficient activation of existing deactivated Ti-Mn-based AB2 hydrogen storage alloys, restoring good initial kinetics and hydrogen storage capacity. Without significantly affecting the alloy cost, it can activate large quantities of long-term deactivated Ti-Mn-based AB2 alloys, promoting the widespread use of Ti-Mn-based AB2 alloys in solid-state hydrogen storage devices.

[0020] 2) Specifically, in the activation process of this invention, the grinding step aims to ensure thorough alloy mixing and prevent elemental segregation, thereby guaranteeing the accuracy and repeatability of the sampling test results. Compacting the powdered sample before remelting avoids the loss of some elements due to their lower melting point caused by powder metallurgy during the remelting process, ensuring the reliability of the test results. Multiple flipping and remelting during the remelting process aims to improve the uniformity of the alloy melting and prevent the phenomenon where the outside is melted while the inside remains solid. Throughout the entire process, except for the brief sample transfer step in air, all other steps are performed in a glove box under an Ar protective atmosphere to minimize sample contact with air, thus reducing air interference with the test results. During the testing process, vacuuming is performed before volume calibration and relevant performance tests to eliminate the influence of impurity gases that may be present inside the testing device and the sample spoon on the test results, ensuring the accuracy of the test results.

[0021] 3) The preparation process of this invention only requires physical mixing followed by simple pressing and melting in an electric arc furnace. It eliminates the need for prolonged high-temperature heat treatment to obtain the novel multiphase alloy TM-LN-V with excellent activity. This improves the activation efficiency of deactivated Ti-Mn-based AB2 alloys, saves activation costs, and provides a new strategy for activating commercially viable solid-state hydrogen storage materials that have been deactivated over time. Results show that co-doping with 5wt.% LaNi5 + 5wt.% V can efficiently activate long-deactivated Ti-Mn-based AB2 hydrogen storage alloys. The newly formed multiphase alloy TM-LN-V exhibits both good kinetic properties and hydrogen storage capacity. Attached Figure Description

[0022] Figure 1 These are the hydrogen absorption kinetics test curves of the products from five long-stored Ti-Mn-based AB2 alloys in Example 1 after being treated in different ways;

[0023] Figure 2 (a)-(b) are the hydrogen adsorption / desorption curves of the 1st and 5th cycles of the 5 samples of long-stored Ti-Mn-based AB2 alloys after different treatments in Example 1, respectively.

[0024] Figure 3 These are the XRD patterns of the five samples of long-stored Ti-Mn-based AB2 alloys from Example 1 after being treated in different ways;

[0025] Figure 4 This is a SEM morphology and elemental distribution mapping of the TM-LN-V alloy prepared in Example 1;

[0026] Figure 5 These are the PCT test results of the TM-LN-V alloy prepared in Example 1 after 1, 5, 10, and 20 cycles.

[0027] Figure 6 The images show the XRD patterns of the TM-LN-V alloy prepared in Example 1 before hydrogen absorption / desorption and after 5, 10, and 20 hydrogen charge / desorption cycles. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0029] Example 1

[0030] This embodiment provides a method for reactivating a deactivated Ti-Mn-based AB2-type hydrogen storage alloy, specifically including the following steps:

[0031] 1) Take a commercially available Ti-Mn-based AB2 hydrogen storage alloy that has been stored in air for one year without being opened in its original packaging. The alloy composition is TiMn. 1.5 Cr 0.4 V 0.2 Zr 0.1 Fe 0.05 Marked as TM, the hydrogen storage alloy was divided into 5 equal parts;

[0032] 2) Keep the first copy as is, without any processing, and name it TM;

[0033] The second part was remelted in a vacuum arc furnace at 1800℃. After one side was melted and cooled, it was flipped and melted again. This process was repeated multiple times to ensure that each geometric face of the block was melted once. The melting time for each face was 5 minutes. After melting, the block was crushed and recycled in an Ar protective glove box to obtain the remelted Ti-Mn-based AB2 hydrogen storage alloy, denoted as TM-remelt.

[0034] The third batch was mixed with LaNi5 alloy powder in an Ar protective glove box, with a mixing mass ratio of Ti-Mn-based AB2 alloy to LaNi5 of 90:10. After grinding for 30 minutes until uniformly mixed, the mixture was manually pressed into blocks using a pressure of 25 MPa to obtain bulk materials. The blocks were then melted in a vacuum arc furnace at 1800°C. After one side was melted, the blocks were cooled and then flipped to melt the other side. This process was repeated multiple times to ensure that each geometric face of the block was melted once, with each face being melted for 5 minutes. After melting, the blocks were crushed and recycled in an Ar protective glove box to obtain a Ti-Mn-based AB2 hydrogen storage alloy doped with LaNi5 alloy, denoted as TM-LN.

[0035] The fourth batch was mixed with metallic V powder in an Ar protective glove box, with a mixing mass ratio of Ti-Mn-based AB2 alloy to V of 90:10. After grinding for 30 minutes until homogeneous, the mixture was manually pressed into blocks using a pressure of 25 MPa to obtain bulk materials. The blocks were then melted in a vacuum arc furnace at 1800°C. After one side was melted, the blocks were cooled and then flipped to melt the other side. This process was repeated multiple times to ensure that each geometric face of the block was melted once, with each face being melted for 5 minutes. After melting, the blocks were crushed and recycled in an Ar protective glove box to obtain a Ti-Mn-based AB2 hydrogen storage alloy doped with metallic V, denoted as TM-V.

[0036] The fifth batch was mixed with LaNi5 alloy powder and metallic V powder in an Ar protective glove box. The mass ratio of Ti-Mn-based AB2 alloy to LaNi5 and V was 90:5:5. After grinding for 30 minutes until homogeneous, the mixture was manually pressed into blocks using a pressure of 25 MPa to obtain bulk materials. The blocks were then melted in a vacuum arc furnace at 1800°C. After one side was melted, the blocks were cooled and then flipped to melt the other side. This process was repeated multiple times to ensure that each geometric face of the block was melted once, with each face being melted for 5 minutes. After melting, the blocks were pulverized and recycled in an Ar protective glove box to obtain a Ti-Mn-based AB2 hydrogen storage alloy doped with LaNi5 alloy and metallic V, denoted as TM-LN-V.

[0037] Performance testing

[0038] 1) Five samples of long-stored Ti-Mn-based AB2 alloy were treated in different ways, and hydrogen absorption kinetics were tested at 6 MPa hydrogen pressure and room temperature (303 K). The results are as follows: Figure 1As shown in curve (1), by Figure 1 It can be known that:

[0039] At 6 MPa hydrogen pressure and room temperature, Ti-Mn-based AB2 hydrogen storage alloy (TM) stored for one year completely lost its activity and had no hydrogen absorption capacity. In contrast, the remelted Ti-Mn-based AB2 hydrogen storage alloy (TM-remelt) began to slowly absorb hydrogen at 303 K and 6 MPa hydrogen pressure, reaching a hydrogen absorption capacity of 0.50 wt.% after 1.5 hours.

[0040] The hydrogen absorption kinetics of the Ti-Mn-based AB2 hydrogen storage alloy (TM-LN) doped with LaNi5 alloy (10 wt.%) were significantly accelerated, reaching 0.75 wt.% within 90 seconds, indicating that the addition of a small amount of LaNi5 alloy significantly enhanced the hydrogen absorption kinetics of the deactivated Ti-Mn-based AB2 hydrogen storage alloy. After 90 seconds, the hydrogen absorption rate of the TM-LN alloy slowed down, and the total hydrogen absorption increased from 0.75 wt.% to 1.12 wt.% within 1.5 hours.

[0041] In the Ti-Mn-based AB2 hydrogen storage alloy (TM-V) doped with 10 wt.% V, the initial hydrogen absorption kinetics gradually increased, exhibiting a parabolic absorption curve. However, compared to the TM-LN alloy, its early kinetics were slower, absorbing only 0.10 wt.% hydrogen within 90 seconds, reaching a comparable hydrogen absorption capacity within 1100 seconds. After 1100 seconds, the TM-V alloy continued to absorb hydrogen, reaching a maximum of 2.05 wt.% after 1.5 hours. This indicates that the addition of V not only enhanced the alloy's kinetics to some extent but also increased or restored the hydrogen absorption capacity of the deactivated Ti-Mn-based AB2 alloy.

[0042] The Ti-Mn-based AB2 hydrogen storage alloy (TM-LN-V), co-doped with LaNi5 (5 wt.%) and metallic V (5 wt.%), combines the advantages of both TM-LN and TM-V alloys, exhibiting not only rapid initial hydrogen absorption kinetics but also a high hydrogen storage capacity. Within 360 seconds, the hydrogen absorption rapidly reached over 1.60 wt.%, followed by continued hydrogen absorption, albeit at a slower rate. After 1.5 hours, the hydrogen absorption reached 2.00 wt.%. These experimental results demonstrate that co-doping with LaNi5 and V is a highly efficient strategy for recovering / enhancing long-term deactivated Ti-Mn alloys.

[0043] 2) The hydrogen adsorption and desorption curves of five Ti-Mn-based AB2 alloys treated differently in Example 1 at room temperature (303K) were tested for one and five cycles. The specific test method was as follows: Initial kinetic performance tests were performed on the five samples using a Sievert high-pressure hydrogen adsorption analyzer (GASPRO) manufactured by SETARAM, France. 0.5 g of the TM sample from Example 1 was filled into a sample test spoon. The test temperature was set to 303K, and after evacuation for 30 minutes, volume calibration was performed using high-purity helium. Then, initial kinetic tests were conducted at a hydrogen pressure of 6 MPa. After the test, samples treated in other ways were used, and the above test steps were repeated. Long-cycle PCT tests were performed at 303K. The test scheme was as follows: hydrogen adsorption process: single pressure increase of 0.8 MPa, upper limit pressure of 6 MPa, and longest single-point test time of 60 minutes; hydrogen desorption process: single pressure decrease of 1.2 MPa, lower limit pressure of 0.01 MPa, and longest single-point test time of 30 minutes. The results are as follows: Figure 2 As shown in (a)-(b), where (a) is the hydrogen adsorption / desorption curve for one cycle, and (b) is the hydrogen adsorption / desorption curve for five cycles. Figure 2 It can be known that:

[0044] The PCT curve of the untreated Ti-Mn-based AB2 alloy(TM) is almost linear, and it remains linear even after 5 cycles, indicating that the Ti-Mn-based AB2 alloy stored for 1 year no longer has reversible hydrogen absorption and desorption properties.

[0045] The remelted Ti-Mn-based AB2 hydrogen storage alloy (TM-remelt) showed a slight improvement in hydrogen absorption and desorption performance, but it remained very low, with the initial maximum hydrogen absorption reaching only 0.50 wt.%. Simultaneously, its reversibility was significantly poor; after five cycles, its PCT curve tended towards a straight line with no obvious hydrogen absorption / desorption plateau, and the reversible hydrogen absorption decreased to less than 0.10 wt.%, indicating that even after remelting, the long-stored Ti-Mn-based AB2 alloy still does not possess true hydrogen storage performance.

[0046] In contrast, Ti-Mn alloys treated with LaNi5 and / or V all exhibited recovered or significantly enhanced reversible hydrogen absorption and desorption properties. The doped Ti-Mn-based AB2 alloys all showed distinct hydrogen absorption and desorption plateaus, with the absorption plateau ranging from 1.74 to 5.10 MPa and the desorption plateau from 0.68 to 2.25 MPa. The hydrogen absorption and desorption capacities are as follows: the TM-LN alloy exhibited an initial hydrogen absorption capacity of 1.60 wt.%, and even after 5 cycles, it maintained a reversible hydrogen storage capacity of over 1.45 wt.%, with a capacity retention of 90.63%. The TM-V alloy exhibited the largest initial hydrogen absorption capacity, reaching 2.05 wt.%, but its reversibility was relatively poor, maintaining only 1.75 wt.% of the reversible hydrogen storage capacity after 5 cycles, with a capacity retention of 85.37%. The TM-LN-V alloy achieved a maximum initial hydrogen absorption capacity of 1.80 wt.%, and after five cycles, it maintained a reversible hydrogen storage capacity of 1.55 wt.%, with a capacity retention rate of 86.11%. The Ti-Mn-based AB2 hydrogen storage alloy, co-doped with LaNi5 and metallic V, not only has high hydrogen absorption and desorption capacity but also relatively good cycle stability.

[0047] 3) XRD pattern structure analysis was performed on five samples of Ti-Mn-based AB2 alloys that had been treated in different ways during long-term storage, as shown in the results. Figure 3 As shown. By Figure 3 It can be known that:

[0048] All five alloys consisted of the Laves phase (TiMnCr), indicating that a small amount of doping (10 wt.%) did not generate a new crystal structure. However, new diffraction peaks (26.22°, 29.18°, 30.06°, 35.74°, 46.22°, 52.26°, 62.60°) appeared in TM-LN and TM-LN-V. This indicates that the addition of alloy LaNi5 generated a new phase in the Ti-Mn-based AB2 hydrogen storage alloy, forming a multiphase alloy. Further analysis revealed that the diffraction peaks at 26.22°, 29.18°, 30.06°, 46.22°, and 52.26° originated from La₂O₃, while the diffraction peaks at 35.74° and 62.60° originated from NiFe₂O₄. No diffraction peaks of LaNi₅ were detected, indicating that La and Ni separated in the new multiphase alloy, forming La and NiFe₂. During the preparation for SEM testing, they underwent an oxidation reaction to form La₂O₃ and NiFe₂O₄.

[0049] 4) SEM morphology and elemental distribution mapping of the TM-LN-V alloy prepared in Example 1, wherein: (a) is a 500X magnified view of a portion of the TM-LN-V alloy; (b) is a 1000X magnified view of a portion of the TM-LN-V alloy; (c) is a 5000X magnified view of a portion of the TM-LN-V alloy; (d) is a Ti elemental distribution mapping of a portion of the TM-LN-V alloy at 5000X magnification; (e) is a Mn elemental distribution mapping of a portion of the TM-LN-V alloy at 5000X magnification; (f) is a La elemental distribution mapping of a portion of the TM-LN-V alloy at 5000X magnification; (g) is a... (h) is a mapping diagram of Ni element distribution in a 5000X magnified view of the TM-LN-V alloy; (i) is a mapping diagram of Zr element distribution in a 5000X magnified view of the TM-LN-V alloy; (j) is a mapping diagram of Cr element distribution in a 5000X magnified view of the TM-LN-V alloy; (k) is a mapping diagram of Fe element distribution in a 5000X magnified view of the TM-LN-V alloy; (l) is a mapping diagram of O element distribution in a 5000X magnified view of the TM-LN-V alloy.

[0050] from Figure 4 As can be seen, TM-LN-V exhibits a clear morphology of a multiphase alloy. In SEM, the gray matrix phase is TM, and the white portion is the newly formed La-rich phase, which is interspersed within the TM matrix phase. Mapping results show that a small amount of Ti segregation occurs in the alloy, forming a Ti-rich phase. The elemental distribution of the matrix phase, La-rich phase, Ti-rich phase, and the entire mapping region in the TM-LN-V multiphase alloy is shown in Table 1 below. This confirms that the multiphase alloy of this invention introduces new phases and phase interfaces, providing more catalytically active sites and hydrogen diffusion channels for the matrix alloy, which is an effective strategy to improve the hydrogen storage performance of the alloy.

[0051] Table 1

[0052]

[0053] 5) To verify the cycling stability of the LaNi5 and V co-doped TM-LN-V multiphase alloy, 20 PCT tests were conducted at room temperature (303 K) and a hydrogen pressure of 6 MPa. The specific test method was as follows: 0.5 g of TM-LN-V alloy powder sample was placed in a sample test spoon, and the test temperature was set to 303 K. After evacuating for 30 minutes and calibrating the volume using high-purity helium, hydrogen absorption and desorption cycle tests were performed. The test scheme was as follows: hydrogen absorption process: single pressure increase of 0.8 MPa, upper limit pressure of 6 MPa, and a maximum test time of 60 minutes at a single point; hydrogen desorption process: single pressure decrease of 1.2 MPa, lower limit pressure of 0.01 MPa, and a maximum test time of 30 minutes at a single point. The PCT test results for the first, 5th, 10th, and 20th cycles are shown below. Figure 5 As shown, the different curves represent the following meanings: 1 st ab represents the hydrogen absorption curve of the TM-LN-V alloy during the first PCT cycle; 1 st de represents the hydrogen desorption curve of the TM-LN-V alloy during the first PCT cycle; 5 th ab represents the hydrogen absorption curve of the TM-LN-V alloy during the fifth PCT cycle; 5 th de represents the hydrogen desorption curve of the TM-LN-V alloy during the fifth PCT cycle; 10 th ab represents the hydrogen absorption curve of the TM-LN-V alloy after the tenth PCT cycle; 10 th de represents the hydrogen desorption curve of the TM-LN-V alloy during the tenth PCT cycle; 20 th ab represents the hydrogen absorption curve of the TM-LN-V alloy after the 20th PCT cycle; 20 th de represents the hydrogen desorption curve of the TM-LN-V alloy during the twentieth PCT cycle.

[0054] from Figure 5 It can be seen that the maximum hydrogen absorption capacity of the TM-LN-V multiphase alloy in the initial PCT cycle can reach 1.80 wt.%, after 5 cycles its reversible hydrogen absorption capacity is about 1.50 wt.%, after 10 cycles its reversible hydrogen absorption capacity is 1.45 wt.%, and after 20 cycles its reversible hydrogen absorption capacity remains at 1.45 wt.% and no longer decreases. This indicates that the TM-LN-V alloy remains stable after 5 cycles and has practical value.

[0055] 6) XRD analysis was performed on the collected TM-LN-V samples before and after hydrogen absorption and desorption. The results are as follows: Figure 6 As shown. Figure 6The XRD patterns of TM-LN-V alloy before hydrogen absorption / desorption and after 5, 10, and 20 hydrogen absorption / desorption cycles are shown. Specifically: (a) is the XRD pattern of TM-LN-V alloy before hydrogenation; (b) is the XRD pattern of TM-LN-V alloy after 5 PCT cycles; (c) is the XRD pattern of TM-LN-V alloy after 10 PCT cycles; and (d) is the XRD pattern of TM-LN-V alloy after 20 PCT cycles. Figure 6 It can be seen that all TM-LN-V alloys exhibit the TiMnCr-Laves phase regardless of whether they are before or after hydrogenation, indicating that TM-LN-V has good cycle stability. Furthermore, after 5 and 20 hydrogen adsorption / desorption cycles, the intensity and position of its diffraction peaks hardly change. This further verifies the high cycle stability of this alloy in a hydrogen environment, highlighting the great potential of TM-LN-V multiphase alloys in practical applications.

[0056] Those skilled in the art should understand that the above descriptions are merely several specific embodiments of the present invention, and not all embodiments. It should be noted that many modifications and improvements can be made by those skilled in the art, and all modifications or improvements not exceeding the scope of the claims should be considered within the protection scope of the present invention.

Claims

1. A method for activating a deactivated Ti-Mn-based AB2-type hydrogen storage alloy, characterized in that, Includes the following steps: S1. Take deactivated Ti-Mn-based AB2 type hydrogen storage alloy, LaNi5 alloy powder and metallic V powder, grind and mix them in a glove box under protective atmosphere at a mass ratio of (90-100):(1-5):(1-5), and then press them into blocks to obtain bulk materials; S2. Place the block material in a vacuum electric arc furnace and melt it at a temperature of 1500-2000℃. After melting, crush it in an Ar-protected glove box to obtain a high-performance Ti-Mn-based AB2 type multiphase hydrogen storage alloy, thus completing the activation process of the deactivated Ti-Mn-based AB2 type hydrogen storage alloy.

2. The activation method for a deactivated Ti-Mn-based AB2-type hydrogen storage alloy according to claim 1, characterized in that, The grinding time in step S1 is more than 5 minutes.

3. The activation method for a deactivated Ti-Mn-based AB2-type hydrogen storage alloy according to claim 1, characterized in that, The protective atmosphere is one of He, Ar, or N2 gas.

4. The activation method for a deactivated Ti-Mn-based AB2-type hydrogen storage alloy according to claim 1, characterized in that, The pressure of the pressure block in step S1 is 10MPa-40MPa.

5. The activation method for a deactivated Ti-Mn-based AB2-type hydrogen storage alloy according to claim 1 or 4, characterized in that, The block is cylindrical, with a diameter of 8mm-40mm and a height of 4mm-30mm.

6. The activation method for a deactivated Ti-Mn-based AB2-type hydrogen storage alloy according to claim 1, characterized in that, In step S2, when the block is being melted, after one side is melted and cooled, it is flipped over to melt the other side. This process is repeated multiple times to ensure that each geometric face of the block is melted at least once, with each face taking 5-6 minutes to melt.

7. The activation method for a deactivated Ti-Mn-based AB2-type hydrogen storage alloy according to claim 1, characterized in that, In step S2, the vacuum degree of the vacuum arc furnace is P0≤10Pa, and the melting time is 5-6min.

8. The activation method for a deactivated Ti-Mn-based AB2-type hydrogen storage alloy according to claim 1, characterized in that, In step S2, the diameter of the particles after the block material is 0.1mm-1mm after melting and crushing.

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