A multi-component high magnesium alloy hydrogen storage material and preparation method thereof

Abstract

The present invention relates to a multi-component high-magnesium alloy hydrogen storage material and a preparation method thereof. The structure of the material is Mg 90 Ni 2.5 Cu 2.5 La 2.5 LN 2.5 , where LN = Ce, Sm, Gd or Pr; the preparation method includes the following steps: weighing elemental materials with corresponding atomic ratios and performing three smelting operations. The first smelting temperature is about 1200-1400 °C; the second smelting temperature is about 1400-1600 °C; when the third smelting temperature is 1500 °C, a strip casting operation is carried out to obtain an alloy ingot strip material Mg 90 Ni 2.5 Cu 2.5 La 2.5 LN 2.5 . The hydrogen storage capacity of the present invention can reach a high capacity of 5.83 wt%, and the kinetic performance of the material is significantly improved. Hydrogen evolution can start at 160 °C at a heating rate of 3 °C / min, greatly reducing the initial hydrogen evolution temperature of magnesium hydride. The material prepared by the present invention is easy to obtain, has a low cost, the preparation method is simple to operate, has low energy consumption, and is suitable for large-scale industrial production.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrogen storage materials and relates to a multi-component high-magnesium-containing alloy hydrogen storage material and a preparation method thereof. Background Art

[0002] The unstoppable trend of rapid development of the global society has also led to a rapid increase in energy demand. The current global energy supply demand is mainly carried out by fossil energy. Hydrogen energy is currently one of the most promising alternative energy sources. In the process of utilizing hydrogen energy, the storage and transportation of hydrogen is the biggest difficulty in the use of hydrogen energy. Solid-state hydrogen storage is the most effective hydrogen storage method among various hydrogen storage methods. Hydride solid hydrogen storage is the best hydrogen storage method with the characteristics of large hydrogen storage capacity, good hydrogen absorption thermodynamics, high purity, and good safety performance. At present, the theoretical hydrogen storage capacity of magnesium-based hydrogen storage materials is 7.6wt%, and the hydrogen absorption and desorption platform is stable. However, due to the material defects of magnesium hydride itself, the stability of the Mg-H bond is strong, the Mg / MgH2 kinetic energy barrier is high, and the high pressure and high temperature during the hydrogen absorption and desorption process cause the particles to agglomerate. From these aspects, the temperature of magnesium hydride during the hydrogen absorption and desorption process is high, the rate is slow, and the hydrogen storage capacity is greatly reduced during the cycle.

[0003] Application No. 201510505521.7 discloses a high-capacity Mg-Ni-Cu-La hydrogen storage alloy, which is composed of four components: Mg, Ni, Cu, and La. The atomic percentage of each component in the hydrogen storage alloy is as follows: Mg, 77%; Ni, 10-15%; Cu, 5-10%; La, 3%. The problems are: 1. Due to the low content of Mg and the large amount of transition elements added, the high hydrogen storage characteristics of magnesium hydride materials are affected, resulting in a small hydrogen storage capacity; 2. Due to the lack of significant improvement in the kinetic properties of the material, the initial dehydrogenation temperature is not further reduced.

[0004] In summary, continuous optimization of hydrogen storage materials and methods has become a key research direction for researchers in this field. Summary of the invention

[0005] The present invention provides a high-magnesium alloy hydrogen storage material and a preparation method thereof, so as to solve the problems in the prior art that magnesium hydride has a high temperature and a slow rate during hydrogen absorption and desorption, and the hydrogen storage capacity is greatly reduced during the circulation process.

[0006] In order to achieve the above object, the present invention is implemented by the following technical scheme: a multi-component high magnesium alloy hydrogen storage material, the material is Mg 90 Ni 2.5 Cu 2.5 La 2.5 LN 2.5, wherein LN=Ce, Sm, Gd or Pr.

[0007] Furthermore, the preparation method of the above-mentioned multi-component high magnesium-containing alloy hydrogen storage material comprises the following steps:

[0008] S1, according to Mg 90 Ni 2.5 Cu 2.5 La 2.5 Ln 2.5 The stoichiometric ratio is set, and the element materials with the corresponding atomic ratio are weighed, wherein the Mg particles need to have an excess of 10wt.% of the mass of the Mg element. The selected four elements are pressed into tablets, and the Mg particles and the sheet materials are placed in a graphite nozzle crucible.

[0009] S2, after the suspension smelting belt-spinning machine is evacuated, it is filled with protective atmosphere, and smelting is performed three times. During the third smelting, the belt-spraying operation is performed to obtain the alloy ingot material Mg 90 Ni 2.5 Cu 2.5 La 2.5 LN 2.5 .

[0010] Furthermore, the Mg used is Mg particles with a purity of 99.99%, and the other elements are powders with a purity greater than 99.9%, and are pressed into cylindrical blocks.

[0011] Furthermore, during the belt spraying operation in the above step S2, the protective gas in the chamber of the suspension smelting belt-spinning machine is 0.05-0.2 MPa argon gas, and the spraying gas pressure is 0.2-0.4 MPa.

[0012] Furthermore, in the above step S2, when the spray belt is operated, the rotation speed of the copper roller is 16-64 m / s.

[0013] Furthermore, in the above step S2, the first melting temperature is about 1200-1400°C; the second melting temperature is about 1400-1600°C; and when the third melting temperature is 1500-1600°C, a belt spraying operation is performed.

[0014] Furthermore, the above preparation method produces a multi-component high-magnesium alloy hydrogen storage material.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The main phase of the hydrogen storage material of the present invention is Mg 17The La2-type phase has a Mg content of up to 90at%, and the hydrogen storage performance is significantly improved. At the same time, the content of the transition metal elements added by the present invention is relatively low. Since transition metals have been proven to greatly improve the hydrogen storage performance of magnesium hydride, the present invention adopts the background of maintaining high Mg content and adding trace transition metals, so that multiple transition metals play a synergistic role in hydrogen absorption and desorption, and greatly improve its hydrogen desorption temperature and hydrogen desorption rate. The present invention improves the hydrogen storage performance of Mg / magnesium hydride materials from these two aspects. The alloy hydrogen storage capacity can reach a high capacity of 5.8wt%, and the four transition elements provided by the present invention play the role of catalytic phases in the alloy. The kinetic performance of the material is significantly improved. Hydrogen can be desorbed at 160°C at a heating rate of 3°C / min, which greatly reduces the initial hydrogen desorption temperature of magnesium hydride.

[0017] 2. The materials prepared by the present invention are easy to obtain and low in cost, and are suitable for industrial preparation needs.

[0018] 3. The present invention improves magnesium hydride by using alloying direction, performs three smeltings, and performs belt throwing during the third smelting. The preparation method is simple to operate, consumes less energy, and is suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 1 is the X-ray diffraction diagram of the hydrogen storage material of Examples 1-4 of the present invention.

[0020] Figure 2 This is a scanning electron microscope image of the hydrogen storage material of Example 3 of the present invention.

[0021] Figure 3 This is the first non-isothermal hydrogen release diagram of the hydrogen storage material of Examples 1-4 of the present invention.

[0022] Figure 4 This is the second non-isothermal hydrogen release diagram of the hydrogen storage material of Examples 1-4 of the present invention. DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Embodiment 1, a method for preparing a multi-component high magnesium-containing alloy hydrogen storage material, specifically comprising the following steps:

[0025] S1. Weigh 0.46g Ni, 0.498g Cu, 1.088g La, and 1.098g Ce powders, mix them evenly, and press them into columnar shapes using a tablet press. Since the boiling point of Mg is 1090°C, the Mg element needs to be weighed 10wt.% more than the original Mg mass. In this example, 7.541g Mg particles are weighed.

[0026] S2. Put the mixed flake material and Mg particles into the graphite nozzle, close the hatch, evacuate the belt spinning machine, fill it with 0.15Mpa argon atmosphere, adjust the copper roller rotation speed to 1500r / min, adjust the nozzle spray pressure to 0.3Mpa argon, and perform three smeltings:

[0027] The first time, the melting temperature is 1250℃, so that Mg, Cu, La and Ce are evenly mixed; the second time, the melting temperature is raised to 1350℃, and Ni is mixed; the third time, the melting temperature reaches 1550℃, the material is completely melted, the elements are fully mixed, and the gas is ejected to spray the material out of the nozzle. Through the rapid cooling of the copper roller, the material is subjected to the rapid quenching effect, so that the material produces an amorphous structure, forming an alloy ingot with hydrogen storage alloy;

[0028] S3, the strip sample is made of alloy ingot material Mg 90 Ni 2.5 Cu 2.5 La 2.5 Ce 2.5 .

[0029] Embodiment 2, a method for preparing a multi-component high magnesium-containing alloy hydrogen storage material, specifically comprising the following steps:

[0030] S1. Weigh 0.456 g Ni, 0.494 g Cu, 1.080 g La, and 1.169 g Sm powder, mix them evenly, and press them into columnar form using a tablet press. In this embodiment, 7.481 g Mg particles are weighed.

[0031] S2. Put the mixed flake material and Mg particles into the graphite nozzle, close the hatch, evacuate the belt spinning machine, fill it with 0.1Mpa argon atmosphere, adjust the copper roller rotation speed to 2500r / min, adjust the nozzle spray pressure to 0.25Mpa argon, and perform three smeltings:

[0032] In the first process, the melting temperature is 1300°C to evenly mix Mg, Cu, La and Sm; in the second process, the melting temperature is raised to 1400°C to mix Ni; in the third process, the melting temperature reaches 1500°C and the gas is ejected to eject the material out of the nozzle;

[0033] S3, the strip sample is made of alloy ingot material Mg 90 Ni 2.5 Cu 2.5 La 2.5 Sm 2.5 .

[0034] Embodiment 3, a method for preparing a multi-component high magnesium-containing alloy hydrogen storage material, specifically comprising the following steps:

[0035] S1. Weigh 0.454 g Ni, 0.491 g Cu, 1.074 g La, and 1.216 g Gd powders, mix them evenly, and press them into columnar shapes using a tablet press. In this embodiment, 7.442 g Mg particles are weighed.

[0036] S2. Put the mixed flake material and Mg particles into the graphite nozzle, close the hatch, evacuate the belt spinning machine, fill it with 0.05Mpa argon atmosphere, adjust the copper roller rotation speed to 2000r / min, adjust the nozzle spray pressure to 0.2Mpa argon, and perform three smeltings:

[0037] In the first process, the melting temperature is 1200°C to evenly mix Mg, Cu, La and Ce. In the second process, the melting temperature is raised to 1450°C to mix Ni. In the third process, the melting temperature reaches 1550°C and the gas is ejected to eject the material out of the nozzle.

[0038] S3, the strip sample is made of alloy ingot material Mg 90 Ni 2.5 Cu 2.5 La 2.5 G 2.5 .

[0039] Embodiment 4, a method for preparing a multi-component high magnesium-containing alloy hydrogen storage material, specifically comprising the following steps:

[0040] S1. Weigh 0.46 g Ni, 0.498 g Cu, 1.088 g La, and 1.103 g Pr powder, mix them evenly, and use a tablet press to press them into a columnar shape. In this example, 7.537 g Mg particles are weighed.

[0041] S2. Put the mixed flake material and Mg particles into the graphite nozzle, close the hatch, evacuate the belt spinning machine, fill it with 0.2Mpa argon atmosphere, adjust the copper roller rotation speed to 3000r / min, adjust the nozzle spray pressure to 0.35Mpa argon, and perform three smeltings:

[0042] In the first process, the melting temperature is 1300°C to evenly mix Mg, Cu, La and Ce. In the second process, the melting temperature is raised to 1600°C to mix Ni. In the third process, the melting temperature reaches 1600°C and the gas is ejected to eject the material out of the nozzle.

[0043] S3, the strip sample is made of alloy ingot material Mg 90 Ni 2.5 Cu 2.5 La 2.5 Pr 2.5 .

[0044] As shown in Tables 1 and 2, in the performance comparison of Mg-Ni-Cu-La based alloys with the addition of Ce, Sm, Gd and Pr, Ce has the lowest improved initial dehydrogenation temperature, which can start dehydrogenation at 160°C, but in the second dehydrogenation, the amount of dehydrogenation decreases rapidly to only 4.29wt.%; Gd has the best improved hydrogen storage performance, which starts dehydrogenation at 160°C and can reach 5.8wt.%, and can reach 5.34wt.% in the second dehydrogenation, and the hydrogen storage capacity is well maintained.

[0045] Table 1

[0046]

[0047] Table 2

[0048] Material Initial hydrogen release temperature (℃) Total amount of hydrogen released (wt.%) <![CDATA[MgH2]]> 320 6.8 <![CDATA[Mg 90 us 2.5 With 2.5 to 2.5 What 2.5 ]]> 220 4.29 <![CDATA[Mg 90 us 2.5 With 2.5 to 2.5 Sm 2.5 ]]> 220 4.16 <![CDATA[Mg 90 us 2.5 With 2.5 to 2.5 Gd 2.5 ]]> 220 5.34 <![CDATA[Mg 90 us 2.5 With 2.5 to 2.5 Fr. 2.5 ]]> 215 4.26

[0049] See also Figure 1 , you can see the alloy ingot material Mg 90 Ni 2.5 Cu 2.5 La 2.5 LN 2.5 The phase composition of the alloy ingot is Mg. 17 La2 and Mg phases are formed. This indicates that the Ni, Cu and LN elements in the prepared alloy ingot material fully form a solid solution in the material.

[0050] See also Figure 2 , you can see the alloy ingot material Mg 90 Ni 2.5 Cu 2.5 La 2.5 G 2.5 The surface morphology is smooth and flat. After melting, the material fully contacts with the surface of the copper roller, and the rapid quenching effect is fully achieved.

[0051] See also Figure 3 , you can see the alloy ingot material Mg 90 Ni 2.5 Cu 2.5 La 2.5 LN 2.5 (LN=Ce, Sm, Gd, Pr) The first non-isothermal dehydrogenation performance of heating to 400℃ at 3℃ / min, LN=Gd has the best performance, starting to release hydrogen at 170℃, and completely releasing 5.8wt.% hydrogen at 360℃. Compared with the initial dehydrogenation temperature of magnesium hydride at around 320℃, it is greatly improved.

[0052] See also Figure 4, you can see the alloy ingot material Mg 90 Ni 2.5 Cu 2.5 La 2.5 LN 2.5 (LN=Ce, Sm, Gd, Pr) The second non-isothermal dehydrogenation performance when the temperature was increased to 400℃ at 3℃ / min, LN=Gd had the best performance, starting to dehydrogenate at 220℃ and completely releasing 5.34wt.% of hydrogen at 320℃.

[0053] Among the above embodiments, the comprehensive performance of embodiment 3 is the best.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. All equivalent structural changes made using the contents of the description and drawings of the present invention should be included in the patent protection scope of the invention.

Claims

1. A multi-component high magnesium alloy hydrogen storage material, characterized by: The material is Mg 90 Ni 2.5 Cu 2.5 La 2.5 LN 2.5 , where LN = Ce or Sm or Gd or Pr; The preparation method of the material comprises the following steps: S1, according to Mg 90 Ni 2.5 Cu 2.5 La 2.5 Ln 2.5 The stoichiometric ratio of the elements is obtained by weighing the element materials with the corresponding atomic ratio. Mg particles with a purity of 99.99% are used, and the other four elements are powders with a purity greater than 99.9%, wherein the Mg particles are additionally added with 10wt.% of the mass of the Mg element. The other four selected elements are pressed into tablets, and the Mg particles and the flake materials are placed in a graphite nozzle crucible; S2, after the suspension smelting belt-spinning machine is evacuated, it is filled with protective atmosphere, and smelting is performed three times. During the third smelting, the belt-spraying operation is performed to obtain the alloy ingot material Mg 90 Ni 2.5 Cu 2.5 La 2.5 LN 2.5 ;The first smelting temperature is 1200-1400℃; the second smelting temperature is 1400-1600℃; when the third smelting temperature is 1500-1600℃, the spraying operation is carried out.

2. A multi-component high magnesium alloy hydrogen storage material according to claim 1, characterized in that: During the belt spraying operation in step S2, the protective gas in the chamber of the suspension smelting belt-spinning machine is 0.05-0.2 MPa argon gas, and the spraying gas pressure is 0.2-0.4 MPa.

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