Rapid quenching Mg-Ni-Y-Si series hydrogen storage alloy as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of hydrogen storage materials, and relates to a rapid quenching Mg-Ni-Y-Si series hydrogen storage alloy and a preparation method and application thereof.The hydrogen storage alloy is prepared from, by weight, not more than 20% of nickel, not more than 20% of yttrium, not more than 5% of silicon and the balance magnesium, the content of each element is not 0%; the rapidly-quenched Mg-Ni-Y-Si series hydrogen storage alloy is prepared through smelting, rapid quenching and ball milling in sequence, an as-cast alloy obtained after smelting has an Mg phase, an Mg2Ni phase, an LPSO phase and a YNiSi phase, a rapidly-quenched alloy strip obtained after rapid quenching only has the Mg phase, and the rapidly-quenched Mg-Ni-Y-Si series hydrogen storage alloy obtained after ball milling has the Mg phase, the Mg2Ni phase, the LPSO phase and the YNiSi phase. The hydrogen storage alloy has the advantages of being easy to activate, high in hydrogen storage capacity, high in hydrogen storage rate, moderate in hydrogen storage temperature, low in cost and the like, is extremely suitable for a solid hydrogen storage device in a hydrogen energy industry chain, is simple in preparation method, is easy to control an alloy structure, 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 rapid-quenching Mg-Ni-Y-Si series hydrogen storage alloy and a preparation method and application thereof. Background Art

[0002] Human prosperity has always been inseparable from the support of natural resources. For example, natural resources such as oil and natural gas have played an important role in the rapid development of recent decades. However, limited natural resources are facing the problem of over-consumption, resulting in a serious shortage of these energy sources. Therefore, finding new sustainable energy is an urgent problem to be solved.

[0003] Hydrogen energy is considered to be the ultimate energy form of the future as a highly efficient energy source with diverse production methods, no pollution and high calorific value. The hydrogen energy industry chain includes hydrogen production, hydrogen storage, hydrogen transportation and hydrogen application. Among them, hydrogen storage is the most important link in the hydrogen energy industry chain, and the development of hydrogen storage technology plays a vital role in the industrialization of hydrogen energy.

[0004] Common hydrogen storage methods include high-pressure gaseous hydrogen storage, low-temperature liquid hydrogen storage, and solid-state material hydrogen storage. The first two hydrogen storage methods are mature and have been industrialized, while solid-state material hydrogen storage is still in the theoretical research stage and lacks supporting industries, making it difficult to apply on a large scale in a short period of time. Practice has shown that the high-pressure gaseous hydrogen storage method has a low hydrogen storage density and is suitable for short-distance hydrogen transportation. However, with the increase in hydrogen usage and the increase in transportation distance, its transportation cost and safety are difficult to meet the requirements; low-temperature liquid hydrogen storage requires special ultra-low temperature containers, hydrogen is easy to volatilize, and the equipment cost is high. These problems are difficult to solve and difficult to commercialize; in contrast, solid-state material hydrogen storage has the advantages of high hydrogen storage density, good safety, and low energy consumption, and has a good development prospect.

[0005] There are many kinds of solid-state hydrogen storage materials. Metal hydrides can store hydrogen in the form of hydrogen atoms in the material, which is safe and has good reversible and cyclic hydrogen storage performance. They have good application value in business. Among them, magnesium-based hydrogen storage alloys have the highest hydrogen storage density (the theoretical mass hydrogen storage capacity of Mg is as high as 7.6wt.%, and the volume hydrogen storage density is 110kg / m 3 ), and its raw material resources are abundant, the price is low and it is environmentally friendly, so it is considered to be one of the most promising hydrogen storage materials. However, the currently developed magnesium-based hydrogen storage alloys generally have problems such as high thermodynamic stability of hydrogen absorption and desorption and slow kinetics of hydrogen absorption and desorption, which greatly limits their practical application in the field of hydrogen energy. Therefore, it is necessary to develop a new magnesium-based hydrogen storage alloy. Summary of the invention

[0006] In view of this, one of the objects of the present invention is to provide a rapid-quenching Mg-Ni-Y-Si series hydrogen storage alloy; a second object of the present invention is to provide a method for preparing a rapid-quenching Mg-Ni-Y-Si series hydrogen storage alloy; a third object of the present invention is to provide applications of the rapid-quenching Mg-Ni-Y-Si series hydrogen storage alloy in the fields of hydrogen transportation, separation and purification, hydrogen fuel cells or heat storage.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] 1. A rapid quenching Mg-Ni-Y-Si series hydrogen storage alloy, wherein the content of each element in the rapid quenching Mg-Ni-Y-Si series hydrogen storage alloy is as follows, by weight percentage: the content of nickel element does not exceed 20%, the content of yttrium element does not exceed 20%, the content of silicon element does not exceed 5%, and the balance is magnesium element, and the content of each element is not 0%, and the rapid quenching Mg-Ni-Y-Si series hydrogen storage alloy is obtained by smelting, rapid quenching and ball milling in sequence, and the cast alloy obtained after smelting has Mg phase, Mg2Ni phase, LPSO phase, and YNiSi phase, the rapid quenching alloy strip obtained after rapid quenching has only Mg phase, and the rapid quenching Mg-Ni-Y-Si series hydrogen storage alloy obtained after ball milling has Mg phase, Mg2Ni phase, LPSO phase, and YNiSi phase.

[0009] Furthermore, in terms of weight percentage, the content of each element in the Mg-Ni-Y-Si series hydrogen storage alloy is as follows: the content of nickel element is 13.4-16%, the content of yttrium element is 3-5%, the content of silicon element is 0.25-0.35%, and the balance is magnesium element.

[0010] 2. A method for preparing a rapidly quenched Mg-Ni-Y-Si series hydrogen storage alloy, comprising the following steps:

[0011] S1: weighing and mixing raw materials containing four elements of Mg, Ni, Y and Si according to the weight percentage of each element in the rapid quenching Mg-Ni-Y-Si series hydrogen storage alloy described in any one of claims 1 to 2, and then smelting and cooling to obtain a cast alloy;

[0012] S2: cutting the as-cast alloy in step S1 into blocks and subjecting them to rapid quenching treatment to obtain rapid quenching alloy strips;

[0013] S3: Mechanically crushing the rapidly quenched alloy strips in step S2 and then ball milling them to obtain rapidly quenched Mg-Ni-Y-Si series hydrogen storage materials.

[0014] Furthermore, the raw materials containing the four elements of Mg, Ni, Y and Si are metallic Mg, Mg-Ni alloy, Mg-Y alloy and Mg-Si alloy respectively.

[0015] Furthermore, the Mg-Ni alloy is a Mg-30Ni alloy, the Mg-Y alloy is a Mg-30Y alloy, and the Mg-Si alloy is a Mg-5Si alloy.

[0016] Further, in step S2, a rapid quenching treatment is performed by a rapid quenching device arranged under inert atmosphere conditions.

[0017] Further, in step S3, ball milling is performed in an inert atmosphere by using a ball mill.

[0018] Furthermore, the ball-to-material ratio of the ball mill is 20-40:1, the rotation speed is 250-300 rpm / min, and the time is 1-20 hours.

[0019] Furthermore, the ball milling method is: forward ball milling and reverse ball milling are performed alternately, the ball milling is operated for 5 to 15 minutes, and the ball milling is left to stand for 5 to 10 minutes during the alternation.

[0020] 3. Application of the rapidly quenched Mg-Ni-Y-Si series hydrogen storage alloy in the fields of hydrogen transportation, separation and purification, hydrogen fuel cells or thermal storage.

[0021] The beneficial effects of the present invention are:

[0022] 1. The present invention provides a rapid quenching Mg-Ni-Y-Si series hydrogen storage alloy. The Ni, Y and Si elements contained in the hydrogen storage alloy not only have good catalytic dissociation effects, but also can form a large amount of second phases in the alloy, which is helpful to further improve the hydrogen absorption and desorption performance of the magnesium-based hydrogen storage alloy. The experimental results show that after adding rapid quenching in the preparation process of the Mg-Ni-Y-Si alloy with the same composition, the performance is greatly improved. The rapid quenching Mg-Ni-Y-Si alloy completes hydrogen desorption in 35 minutes at 220°C, while the Mg-Ni-Y-Si alloy with the same other conditions that has not been rapidly quenched completes hydrogen desorption in 55 minutes at 220°C. In addition, under the same magnesium content, the hydrogen storage alloy can basically complete the hydrogen desorption process within 3 minutes at 300°C and within 15 minutes at 240°C, while the known Mg-Ni-Y series alloy needs 7 minutes to complete the hydrogen desorption process at 300°C, and the known Mg-Ni-Si series alloy needs 30 minutes to complete the hydrogen desorption process at 240°C. In addition, the hydrogen storage alloy has a high hydrogen storage capacity and can store a large amount of hydrogen in a hydrogen storage tank at a pressure of 3MPa, which is beneficial to reducing the manufacturing cost of equipment such as hydrogen storage tanks. It can store a large amount of hydrogen even at 220°C, solving the problem that existing magnesium-based alloys cannot maintain a high hydrogen storage capacity below 300°C. At the same time, it also has the advantages of easy activation, fast hydrogen storage rate, suitable hydrogen storage temperature, moderate hydrogen absorption and desorption platform pressure, and high safety. It is suitable for solid-state hydrogen storage equipment in the hydrogen energy industry chain, and is more conducive to promoting the large-scale industrialization of hydrogen energy storage.

[0023] 2. The present invention also provides a method for preparing a rapidly quenched Mg-Ni-Y-Si series hydrogen storage alloy. The method has simple operations and has an obvious effect on homogenization of the structure. The Mg-Ni-Y-Si series hydrogen storage alloy is heated to about 800°C in a rapid quenching device, and argon gas is injected to make the molten alloy fall onto a rapidly rotating copper roller. The copper roller rapidly cools the alloy into an alloy strip at a linear speed of 20 m / s and quickly throws it out. This rapid cooling method allows other elements to be dissolved in Mg to form a supersolid solution. This metastable structure becomes more stable after ball milling. The second phases Mg2Ni, LPSO, YNiSi and other second phases are dissolved out from the Mg phase. Compared with the second phase of the alloy before rapid quenching, the dissolved second phases are smaller and more dispersed. The smaller and more dispersed second phases have a better catalytic effect in the subsequent hydrogen absorption and desorption processes, so that the rapid quenching Mg-Ni-Y-Si hydrogen storage alloy has a faster hydrogen storage rate. In addition, in the preparation process, the alloy material is prepared by melting, rapid quenching and finally ball milling, which makes the process operation simple and controllable, the required equipment is easy to obtain, the preparation cost is low, and it is conducive to large-scale industrial production.

[0024] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0026] Figure 1 The Mg-Ni-Y-Si hydrogen storage alloy MgNi prepared in step S2 of the embodiment 7.8 Y 1.7 Si 0.3 (abbreviated as Melt-spinning MgNi 7.8 Y 1.7 Si 0.3 -1) Comparative Example Step S1 prepared Mg-Ni-Y-Si system hydrogen storage alloy MgNi 7.8 Y 1.7 Si 0.3 (abbreviated as MgNi 7.8 Y 1.7 Si 0.3 -1) Corresponding XRD pattern;

[0027] Figure 2 The Mg-Ni-Y-Si hydrogen storage alloy MgNi prepared in step S3 of the embodiment 7.8 Y 1.7 Si 0.3 (abbreviated as Melt-spinning MgNi 7.8 Y 1.7 Si 0.3 -2), the cast alloy MgNi prepared in step S2 of the comparative example 7.8 Y 1.7 Si 0.3 (abbreviated as MgNi 7.8 Y 1.7 Si 0.3 -2) Corresponding XRD pattern;

[0028] Figure 3 For rapid quenching MgNi 7.8 Y 1.7 Si 0.3 Isothermal hydrogen absorption and desorption curves of hydrogen storage alloys at 300°C, 280°C, 260°C, 240°C and 220°C, where (a) is the hydrogen absorption curve and (b) is the hydrogen desorption curve.

[0029] Figure 4 MgNi 7.8 Y 1.7 Si 0.3 Isothermal hydrogen absorption and desorption curves of hydrogen storage alloys at 300°C, 280°C, 260°C, 240°C and 220°C, where (a) is the hydrogen absorption curve and (b) is the hydrogen desorption curve.

[0030] Figure 5 For rapid quenching MgNi 7.8 Y 1.7 Si 0.3 Capacity bar graph of hydrogen storage alloy after 230 cycles at 300 °C. DETAILED DESCRIPTION

[0031] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0032] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0033] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0034] Example

[0035] A rapidly quenched Mg-Ni-Y-Si series hydrogen storage alloy, wherein the content of Ni element in the hydrogen storage alloy is 15%, the content of Y element is 5%, the content of Si element is 0.3%, and the balance is Mg element (abbreviated as MgNi 7.8 Y 1.7 Si 0.3 ). The preparation method thereof is specifically as follows:

[0036] S1: prepare pure Mg metal, master alloys Mg-30Ni, Mg-30Y and Mg-5Si, and then weigh and batch the ingredients according to the above requirements for the content of each element in the alloy (since Si element is difficult to dissolve, a proper amount of Mg-5Si master alloy is added during weighing and batching, so that the final prepared alloy can meet the predetermined content of each element), and then melt them in a 35Kg medium frequency electromagnetic induction furnace;

[0037] Specifically, 1144 g of pure Mg metal was first put into the furnace, followed by 2520 g of master alloy Mg-30Ni, 916 g of master alloy Mg-30Y, and 420 g of master alloy Mg-5Si. The furnace was evacuated to 10 -1 Pa, stop evacuating, fill with protective gas argon, and adjust the power for heating when the pressure in the furnace is -0.06atm. After heating at 20KW for 10min, adjust to 40KW, and observe the furnace until the alloy is completely melted (about 5min). After the alloy in the furnace is completely melted, keep it warm for 3min, then cast it into a stainless steel mold, cool it under vacuum for 40min, and then take it out to obtain the cast alloy MgNi 7.8 Y 1.7 Si 0.3 (abbreviated as MgNi 7.8 Y 1.7 Si 0.3 -1);

[0038] S2: The cast alloy MgNi prepared in step S1 7.8 Y 1.7 Si 0.3 The blocks were cut and then transferred to a rapid quenching device for rapid quenching. The copper roller speed was set to 20 m / s (linear speed). The rapid quenching device was placed in a glove box (to prevent oxidation of the prepared alloy) for rapid quenching to obtain rapid quenching MgNi 7.8 Y 1.7 Si 0.3 Alloy strip (abbreviated as Melt-spinning MgNi 7.8 Y 1.7 Si 0.3 -1).

[0039] S3: The rapidly quenched MgNi prepared in step S2 7.8 Y1.7 Si 0.3 The alloy strips were mechanically crushed and then transferred to a high-energy ball mill for ball milling under argon conditions (the ball mill was in an inert gas atmosphere to prevent oxidation of the prepared alloy). During ball milling, the mass ratio of stainless steel grinding balls to the rapidly quenched alloy was 20:1, the rotation speed was 250 rpm / min, and the mill rotated forward for 5 minutes, paused for 5 minutes, and then reversed for 5 minutes (this ball milling method can avoid the problem of excessive alloy temperature during ball milling and help improve ball milling efficiency). After ball milling for 6 hours, the rapidly quenched Mg-Ni-Y-Si hydrogen storage alloy MgNi 7.8 Y 1.7 Si 0.3 (abbreviated as Melt-spinning MgNi 7.8 Y 1.7 Si 0.3 -2).

[0040] Comparative Example

[0041] A Mg-Ni-Y-Si series hydrogen storage alloy, wherein the content of Ni element in the hydrogen storage alloy is 15%, the content of Y element is 5%, the content of Si element is 0.3%, and the balance is Mg element (abbreviated as MgNi 7.8 Y 1.7 Si 0.3 ). The preparation method thereof is specifically as follows:

[0042] S1: prepare pure Mg metal, master alloys Mg-30Ni, Mg-30Y and Mg-5Si, and then weigh and batch the ingredients according to the above requirements for the content of each element in the alloy (since Si element is difficult to dissolve, a proper amount of Mg-5Si master alloy is added during weighing and batching, so that the final prepared alloy can meet the predetermined content of each element), and then melt them in a 35Kg medium frequency electromagnetic induction furnace;

[0043] Specifically, 1144 g of pure Mg metal was first put into the furnace, followed by 2520 g of master alloy Mg-30Ni, 916 g of master alloy Mg-30Y, and 420 g of master alloy Mg-5Si. The furnace was evacuated to 10 -1 Pa, stop evacuating, fill with protective gas argon, and adjust the power for heating when the pressure in the furnace is -0.06atm. After heating at 20KW for 10min, adjust to 40KW, and observe the furnace until the alloy is completely melted (about 5min). After the alloy in the furnace is completely melted, keep it warm for 3min, then cast it into a stainless steel mold, cool it under vacuum for 40min, and then take it out to obtain the cast alloy MgNi 7.8 Y 1.7 Si 0.3 (abbreviated as MgNi 7.8 Y1.7 Si 0.3 -1);

[0044] S2: The cast alloy prepared in step S1 is cut into pieces, and then filed into powder with a file, and then transferred to a high-energy ball mill for ball milling under argon conditions (to prevent oxidation of the prepared alloy). During ball milling, the mass ratio of stainless steel grinding balls to cast alloy particles is 20:1, the rotation speed is 250 rpm / min, and the forward rotation is 5 minutes, then paused for 5 minutes and then reversed for 5 minutes (this ball milling method can avoid the problem of excessive alloy temperature during ball milling and help improve ball milling efficiency). After ball milling for 6 hours, the Mg-Ni-Y-Si hydrogen storage alloy MgNi 7.8 Y 1.7 Si 0.3 (abbreviated as MgNi 7.8 Y 1.7 Si 0.3 -2).

[0045] Performance Testing

[0046] 1. Testing the composition and structure of the Mg-Ni-Y-Si series hydrogen storage alloys prepared in the examples and comparative examples;

[0047] Figure 1 Melt-spinning MgNi alloy prepared in step S2 of the embodiment 7.8 Y 1.7 Si 0.3 -1 and the cast alloy MgNi prepared in step S1 in the comparative example 7.8 Y 1.7 Si 0.3 -1 XRD pattern corresponding to the cut sample;

[0048] Figure 2 Melt-spinning MgNi alloy prepared in step S3 of the embodiment 7.8 Y 1.7 Si 0.3 -2 and the alloy MgNi prepared in step S2 in the comparative example 7.8 Y 1.7 Si 0.3 -2 corresponding XRD pattern;

[0049] Combination Figure 1-2 It can be seen that: cast alloy MgNi 7.8 Y 1.7 Si 0.3 -1 contains Mg phase, Mg2Ni phase, LPSO phase, and YNiSi phase. After rapid quenching, the rapidly quenched cast alloy Melt-spinning MgNi 7.8 Y 1.7Si 0.3 -1 only has Mg phase. This is because the second phase does not precipitate due to rapid solidification. Ni, Y, and Si elements are dissolved in the Mg matrix. This supersaturated solid solution is a metastable phase. After ball milling, the alloy MgNi 7.8 Y 1.7 Si 0.3 -2 phase did not transform, while the rapidly quenched alloy Melt-spinningMgNi 7.8 Y 1.7 Si 0.3 -2, the second phases such as Mg2Ni phase, LPSO phase, and YNiSi phase precipitate from the Mg matrix, and the precipitated second phases are finer than those before rapid quenching. Figure 2 This is reflected in the XRD peak of the rapidly quenched alloy after ball milling.

[0050] 2. The hydrogen storage performance of the Mg-Ni-Y-Si series hydrogen storage alloys prepared in the examples and comparative examples was tested;

[0051] First, the rapidly quenched MgNi prepared in the embodiment 7.8 Y 1.7 Si 0.3 The hydrogen storage alloy was placed at 350℃ for 4 activation cycles of hydrogen absorption and desorption. 7.8 Y 1.7 Si 0.3 The hydrogen storage alloy was placed at 300℃, 280℃, 260℃, 240℃ and 220℃ for isothermal hydrogen absorption and desorption tests. The experimental results are shown in Figure 3 As shown. Among them, Figure 3 (a) is the hydrogen absorption curve. Figure 3 (b) is a hydrogen release curve. 7.8 Y 1.7 Si 0.3 The hydrogen storage alloy was subjected to isothermal hydrogen absorption and desorption tests at 300°C, 280°C, 260°C, 240°C and 220°C. The test results of the two activated alloys were plotted into a table, as shown in Table 1.

[0052] Table 1 Comparison of the activated Mg-15Ni-5Y-0.3Si hydrogen storage alloy (rapidly quenched MgNi 7.8 Y 1.7 Si 0.3 ) and the isothermal hydrogen absorption and desorption rates of the activated Mg-5Ni-15Y-0.3Si hydrogen storage alloy

[0053]

[0054] Through Figure 3-5 The comprehensive analysis of Table 1 shows that:

[0055] (1) The rapidly quenched Mg-Ni-Y-Si hydrogen storage alloy prepared by the present invention has high hydrogen storage performance and excellent hydrogen absorption and desorption performance. The hydrogen storage capacity at 220°C can still reach 4.3wt.%, and it can absorb 3.6wt.% of hydrogen within 30s at 220°C and release 4.3wt.% of hydrogen within 35min. It can be cycled 230 times at 300°C, and the capacity retention rate is as high as 90.36%.

[0056] (2) When the preparation of the hydrogen storage alloy includes a rapid quenching process (corresponding to the embodiment), the alloy has good kinetic properties and good high-temperature hydrogen absorption and desorption kinetics. The comprehensive comparative performance is better than that without the rapid quenching process (corresponding to the comparative example). This shows that a supersaturated solid solution is formed during the rapid quenching process, and a finer second phase is precipitated during the subsequent ball milling process, which has a better catalytic effect. The rapid quenching process has a significant homogenizing effect on the alloy, and the fine second phase formed is conducive to enhancing the catalytic effect on the alloy, thereby improving the kinetic properties, thermodynamic properties and low-temperature properties of the alloy;

[0057] In the above hydrogen storage alloy, the newly introduced rapid quenching process improves the uniformity of catalytic elements and catalytic phases in the alloy. The three elements Ni, Y and Si can change the unit cell volume of the alloy, increase the distance between H atoms and Mg atoms, weaken the Mg-H bond strength, and improve the thermodynamic properties of hydrogen absorption and desorption of metal Mg; a large number of fine Mg2Ni phases, LPSO phases and YNiSi phases are formed inside the alloy, providing diffusion paths and a large number of nucleation sites for H atoms, thereby improving the kinetic properties of hydrogen absorption and desorption of metal Mg. Among them, the LPSO phase and the YNiSi phase are two newly introduced phases in the alloy, which can destabilize MgH2. The nano-Mg2Ni produced by the hydrogen absorption and decomposition of the LPSO phase has a catalytic effect on YH2 and YH3, and can prevent Mg crystals from growing in the cycle, thereby improving the cycle performance of the alloy. After the YNiSi phase absorbs hydrogen, nano-Mg2Ni, YH2, YH3 and Mg2Si phases are produced, producing a synergistic catalytic effect.

[0058] In summary, the present invention provides a rapid quenching Mg-Ni-Y-Si series hydrogen storage alloy and its preparation method and application. The hydrogen storage alloy has a low hydrogen storage temperature and can achieve good hydrogen storage capacity under mild conditions, thereby helping to reduce the cost of hydrogen transportation, meeting the requirements of hydrogen storage tank design, and greatly promoting the industrialization development of hydrogen energy.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A rapidly quenched Mg-Ni-Y-Si series hydrogen storage alloy, wherein the content of each element in the rapidly quenched Mg-Ni-Y-Si series hydrogen storage alloy is as follows: the content of nickel element is not more than 20%, the content of yttrium element is not more than 20%, the content of silicon element is not more than 5%, and the balance is magnesium element, and the content of each element is not 0%, characterized in that: The rapid quenching Mg-Ni-Y-Si series hydrogen storage alloy is prepared by smelting, rapid quenching and ball milling in sequence, and the cast alloy obtained after smelting has Mg phase, Mg2Ni phase, LPSO phase and YNiSi phase, the rapid quenching alloy strip obtained after rapid quenching has only Mg phase, and the rapid quenching Mg-Ni-Y-Si series hydrogen storage alloy obtained after ball milling has Mg phase, Mg2Ni phase, LPSO phase and YNiSi phase.

2. The rapidly quenched Mg-Ni-Y-Si hydrogen storage alloy according to claim 1, characterized in that: Calculated by weight percentage, the contents of each element in the Mg-Ni-Y-Si series hydrogen storage alloy are as follows: the content of nickel element is 13.4-16%, the content of yttrium element is 3-5%, the content of silicon element is 0.25-0.35%, and the balance is magnesium element.

3. A method for preparing a rapidly quenched Mg-Ni-Y-Si series hydrogen storage alloy, characterized in that: The following steps are involved: S1: weighing and mixing raw materials containing four elements of Mg, Ni, Y and Si according to the weight percentage of each element in the rapid quenching Mg-Ni-Y-Si series hydrogen storage alloy described in any one of claims 1 to 2, and then smelting and cooling to obtain a cast alloy; S2: cutting the as-cast alloy in step S1 into blocks and subjecting them to rapid quenching treatment to obtain rapid quenching alloy strips; S3: Mechanically crushing the rapidly quenched alloy strips in step S2 and then ball milling them to obtain rapidly quenched Mg-Ni-Y-Si series hydrogen storage materials.

4. The method for preparing the rapidly quenched Mg-Ni-Y-Si series hydrogen storage alloy according to claim 3, characterized in that: The raw materials containing the four elements of Mg, Ni, Y and Si are respectively metal Mg, Mg-Ni alloy, Mg-Y alloy and Mg-Si alloy.

5. The method for preparing the rapidly quenched Mg-Ni-Y-Si series hydrogen storage alloy according to claim 4, characterized in that: The Mg-Ni alloy is a Mg-30Ni alloy, the Mg-Y alloy is a Mg-30Y alloy, and the Mg-Si alloy is a Mg-5Si alloy.

6. The method for preparing the rapidly quenched Mg-Ni-Y-Si series hydrogen storage alloy according to claim 3, characterized in that: In step S2, a rapid quenching treatment is performed by using a rapid quenching device arranged under an inert atmosphere.

7. The method for preparing the rapidly quenched Mg-Ni-Y-Si series hydrogen storage alloy according to claim 3, characterized in that: In step S3, ball milling is performed under an inert atmosphere by using a ball mill.

8. The method for preparing the rapidly quenched Mg-Ni-Y-Si series hydrogen storage alloy according to claim 7, characterized in that: The ball-to-material ratio of the ball mill is 20-40:1, the rotation speed is 250-300 rpm / min, and the time is 1-20 hours.

9. The method for preparing the rapidly quenched Mg-Ni-Y-Si series hydrogen storage alloy according to claim 8, characterized in that: The ball milling method is: forward ball milling and reverse ball milling are performed alternately, the ball milling is operated for 5 to 15 minutes, and the ball milling is left to stand for 5 to 10 minutes during the alternation.

10. Use of the rapidly quenched Mg-Ni-Y-Si hydrogen storage alloy according to any one of claims 1 to 2 in the fields of hydrogen transportation, separation and purification, hydrogen fuel cells or thermal storage.

Images