Ti-Fe series hydrogen storage alloy and preparation method thereof

Abstract

The invention relates to the technical field of hydrogen storage materials, in particular to a Ti-Fe series hydrogen storage alloy and a preparation method thereof.The general formula of the Ti-Fe series hydrogen storage alloy is Ti (1-x) RexFeyMz, x is larger than 0 and smaller than or equal to 0.1, y is larger than or equal to 0.7 and smaller than or equal to 0.9, z is larger than or equal to 0.05 and smaller than or equal to 0.1, Re is a rare earth element, and M is a transition metal element. The activation performance of the alloy can be improved to different degrees, the activation and inoculation time is shortened, and the stability of cyanide is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen storage materials, and in particular to a Ti-Fe series hydrogen storage alloy and a preparation method thereof. Background Art

[0002] At present, my country is facing two major challenges: energy security and carbon emissions. It is necessary to adjust the current energy structure that is overly dependent on fossil energy and develop in the direction of low-carbon, clean and intelligent. Incorporating hydrogen energy into my country's entire energy system will help improve my country's high-carbon energy structure and ensure energy security. Its application is not only the highly-regarded fuel cell vehicles, but also hydrogen power generation, industrial applications and construction applications. In recent years, with the support of policies, the scale of my country's hydrogen storage material market has maintained stable development, the domestic hydrogen storage material production capacity has been expanding, and the market scale has been expanding.

[0003] Compared with traditional mechanical hydrogen storage, hydrogen storage using physical adsorption and chemical reaction methods has obvious advantages and great prospects. Metal hydrogen storage technology has good application prospects because it is safe and reliable. The development of low-cost, high-capacity hydrogen storage materials suitable for room temperature conditions to ensure the safe and effective storage of hydrogen is the key to solving the large-scale application of hydrogen energy. At present, hydrogen storage materials are mainly focused on developing new materials or modifying existing materials, and the hydrogen storage mechanism of different hydrogen storage materials needs further study. Although many advances have been made in the research of hydrogen storage materials, the existing main hydrogen storage materials have defects to varying degrees, and there is still a long way to go before the large-scale application of hydrogen energy technology. Therefore, it is urgent to study safe, stable, efficient, and long-cycle hydrogen storage materials to realize the industrial preparation of metal hydrogen storage materials.

[0004] In recent years, magnesium-based materials are considered to be a type of solid-state hydrogen storage material with great application prospects due to their advantages such as high hydrogen storage capacity, abundant magnesium resources and low cost. However, their high enthalpy of hydrogen absorption and desorption and low diffusion coefficient of hydrogen in magnesium hydride result in excessively high hydrogen absorption and desorption temperatures and slow hydrogen absorption and desorption rates, which limits their application in the field of hydrogen energy.

[0005] However, titanium-based hydrogen storage alloy powder has good hydrogen storage performance, low cost, and simple hydrogen storage system design, so it has attracted much attention. Titanium-based hydrogen storage alloy powder is abundant in resources, low in cost, and the alloy powder design is relatively simple, but it is not easy to be activated. Hydrogen absorption and desorption need to be carried out at higher temperatures and pressures. It is also susceptible to poisoning by gas impurities such as CO and O2, has serious hysteresis, short cycle life, and performance degradation after repeated hydrogen absorption. Therefore, there is an urgent need for a titanium-based alloy powder ratio with high activation efficiency and low reaction temperature and its preparation method. Summary of the invention

[0006] In order to solve the technical problems of difficulty in activating Ti-Fe series hydrogen storage alloy powder, unstable hydride and high reaction temperature, an embodiment of the present invention provides a Ti-Fe series hydrogen storage alloy and a preparation method thereof.

[0007] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0008] In one aspect, the present invention provides a Ti-Fe series hydrogen storage alloy, wherein the general formula of the Ti-Fe series hydrogen storage alloy is: Ti (1-x) Re x Fe y M z , wherein 0<x≤0.1, 0.7≤y≤0.9, 0.05≤z≤0.1, Re is a rare earth element, and M is a transition metal element.

[0009] In some embodiments, the Re is La, Ce or Cd.

[0010] In some embodiments, M is Co, Mn, Ni, V or Zr.

[0011] In some embodiments, the purity of the raw material of the Ti—Fe based hydrogen storage alloy is ≥ 99.8%.

[0012] In another aspect, the present invention provides a method for preparing a Ti-Fe based hydrogen storage alloy, comprising the following steps:

[0013] The Ti-Fe series hydrogen storage alloy is obtained by mixing the metal raw materials according to their contents in the composition, and performing 3D printing, heat treatment and crushing through laser melting deposition equipment.

[0014] In some embodiments, the purity of each metal raw material in the composition of the Ti-Fe series hydrogen storage alloy is

[0015] ≥99.8%.

[0016] In some embodiments, the parameters of the laser melting deposition 3D printing are laser power 800-1200W, scanning speed 600-1000mm / min, scanning spacing 1-3mm, and layer height 0.2-0.5mm.

[0017] In some embodiments, the specific process of crushing is first crushing and passing through a 200-mesh sieve, and then ball milling under the protection of inert gas. The ball milling conditions are a ball-to-material ratio of 40:1, a rotation speed of 350 rpm, and a 1-hour shutdown for every 2 hours of ball milling.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects:

[0019] (1) The present invention adds transition metal elements to replace part of Fe or Ti in the Ti-Fe alloy, which can improve the activation performance of the alloy to varying degrees, shorten its activation incubation time, and greatly enhance the stability of cyanide.

[0020] (2) The present invention adds rare earth elements, and a large number of cracks are generated in the Ti-Fe alloy due to volume expansion. A large number of fresh unoxidized surfaces are exposed to hydrogen, which facilitates hydrogen to enter the alloy matrix, thereby reducing the hydrogen evolution temperature of the alloy to room temperature.

[0021] (3) The present invention adopts additive manufacturing combined with crushing processing technology to make the composition of the alloy more uniform, increase the relative surface area of ​​the alloy, improve the reaction rate, and reduce the reaction temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a scanning electron microscope image of the powder of the Ti-Fe based hydrogen storage alloy after ball milling in Example 1 of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present disclosure.

[0024] Example 1

[0025] The hydrogen storage alloy is prepared according to the chemical formula Ti 0.97 Ce 0.03 Fe 0.9 Mn 0.05 The determined weight percentage weighs a total of 100g of metal raw materials, mixes them evenly, and then uses laser melting deposition manufacturing equipment to 3D print them. The parameters of 3D printing are: laser power 800W, scanning speed 600mm / min, scanning spacing 1mm, layer height 0.2mm, and the Ti-Fe alloy after printing is crushed and passed through a 200-mesh sieve, and ball milled under inert gas protection. The ball milling conditions are a ball-to-material ratio of 40:1, a speed of 350 rpm, and a shutdown of 1 hour for every 2 hours of ball milling. The reactor is placed at 300K and vacuumed for 1.5h, and 2.5MPa of hydrogen is flushed in. The alloy can react directly with hydrogen, and the alloy can be fully activated after repeated absorption and release of hydrogen 3 times. It is measured that the maximum hydrogen storage capacity of the alloy at 300K and 2.5MPa is 1.92wt%.

[0026] Example 2

[0027] The hydrogen storage alloy is prepared according to the chemical formula Ti 0.94 Ce 0.06Fe 0.8 Mn 0.08 The determined weight percentage weighs a total of 100g of metal raw materials, mixes them evenly, and then uses laser melting deposition manufacturing equipment to perform 3D printing. The parameters of 3D printing are: laser power 1000W, scanning speed 800mm / min, scanning spacing 2mm, layer height 0.4mm, and the Ti-Fe alloy after printing is crushed and passed through a 200-mesh sieve, and ball milled under inert gas protection. The ball milling conditions are a ball-to-material ratio of 40:1, a speed of 350 rpm, and a 1-hour stop for every 2 hours of ball milling. The reactor is placed at 300K and vacuumed for 1.5h, and 2.5MPa of hydrogen is flushed in. The alloy can react directly with hydrogen, and the alloy can be fully activated after repeated absorption and release of hydrogen 3 times. It is measured that the maximum hydrogen storage capacity of the alloy at 300K and 2.5MPa is 2.00wt%.

[0028] Example 3

[0029] The hydrogen storage alloy is prepared according to the chemical formula Ti 0.91 Ce 0.09 Fe 0.7 Mn 0.1 The determined weight percentage weighs a total of 100g of metal raw materials, mixes them evenly, and then uses laser melting deposition manufacturing equipment to 3D print them. The parameters of 3D printing are: laser power 1200W, scanning speed 1000mm / min, scanning spacing 3mm, layer height 0.5mm, and the Ti-Fe alloy after printing is crushed and passed through a 200-mesh sieve, and ball milled under inert gas protection. The ball milling conditions are a ball-to-material ratio of 40:1, a speed of 350 rpm, and a stop of 1 hour for every 2 hours of ball milling. The reactor is placed at 300K and vacuumed for 1.5h, and 2.5MPa of hydrogen is flushed in. The alloy can react directly with hydrogen, and the alloy can be fully activated after repeated absorption and release of hydrogen 3 times. It is measured that the maximum hydrogen storage capacity of the alloy at 300K and 2.5MPa is 1.85wt%.

[0030] Table 1 Hydrogen storage capacity and cycle stability of hydrogen storage alloys with different alloy powder compositions

[0031]

[0032] ——Hydrogen absorption within 5 minutes at an initial hydrogen pressure of 3.5 MPa and 300 K (wt.%);

[0033] ——At the initial pressure of 1×10 -4 The amount of hydrogen released within 30 minutes at MPa and 300K;

[0034] S 100 =C 100 / C max× 100%, where C max is the saturated hydrogen absorption capacity of the alloy, C 100 is the amount of hydrogen absorbed after the 100th cycle.

[0035] The results in Table 1 show that the alloy powder proposed in the present invention has a high hydrogen absorption and desorption capacity and excellent dynamic performance. Compared with similar alloys studied at home and abroad, the hydrogen storage performance of the alloy of the present invention at low temperature has been significantly improved, and the alloy has good hydrogen absorption and desorption cycle stability.

[0036] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0037] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A Ti-Fe based hydrogen storage alloy, characterized in that: The general formula of the Ti-Fe series hydrogen storage alloy is: Ti (1-x) Re x Fe y M z , wherein 0<x≤0.1, 0.7≤y≤0.9, 0.05≤z≤0.1, Re is a rare earth element, and M is a transition metal element.

2. A Ti-Fe based hydrogen storage alloy according to claim 1, characterized in that: The Re is La, Ce or Cd.

3. The Ti-Fe based hydrogen storage alloy according to claim 1, characterized in that: The M is Co, Mn, Ni, V or Zr.

4. The Ti-Fe based hydrogen storage alloy according to claim 1, characterized in that: The purity of the raw materials of the Ti-Fe series hydrogen storage alloy is ≥99.8%.

5. A method for preparing a Ti-Fe based hydrogen storage alloy as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: The Ti-Fe series hydrogen storage alloy is obtained by mixing the metal raw materials according to their contents in the composition, and performing 3D printing, heat treatment and crushing through laser melting deposition equipment.

6. The preparation method according to claim 5, characterized in that: The purity of each metal raw material in the composition of the Ti-Fe series hydrogen storage alloy is ≥99.8%.

7. The preparation method according to claim 5, characterized in that: The parameters of the laser melting deposition 3D printing are laser power 800-1200W, scanning speed 600-1000mm / min, scanning spacing 1-3mm, and layer height 0.2-0.5mm.

8. The preparation method according to claim 5, characterized in that: The specific process of the crushing is first crushing and passing through a 200-mesh sieve, and then ball milling under the protection of inert gas. The ball milling conditions are a ball-to-material ratio of 40:1, a rotation speed of 350 rpm, and a 1-hour stop for every 2 hours of ball milling.

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