A preparation method of AB type hydrogen storage alloy and hydrogen storage alloy

Abstract

The present invention discloses a method for preparing an AB type hydrogen storage alloy, wherein each alloy powder sample is mixed with one-dimensional graphene, two-dimensional graphene, and three-dimensional graphene of the same mass, respectively, to obtain a first mixed alloy sample, a second mixed alloy sample, and a third mixed alloy sample, and then obtain a first hydrogen release fitting curve, a second hydrogen release fitting curve, and a third hydrogen release fitting curve; thereby determining the mixing ratio of one-dimensional graphene, two-dimensional graphene, and three-dimensional graphene, and finally mixing with the alloy powder formed by the alloy raw material to complete the preparation. The present invention analyzes the combination and reaction of the catalyst on one-dimensional, two-dimensional, and three-dimensional graphene loads, determines the optimal parameters of the three, and mixes the three according to the optimal parameters to form a graphene catalyst, thereby being able to slow down the early hydrogen release rate, improve the platform pressure of the AB type hydrogen storage alloy to 3-5 atmospheres, and enable the hydrogen release rate to maintain a high level for a long time, thereby improving stability.

Description

Technical Field

[0001] The invention belongs to the field of hydrogen storage materials, and in particular relates to a preparation method of an AB type hydrogen storage alloy and the hydrogen storage alloy. Background Art

[0002] With the improvement of living standards and the development of industrial production, people's demand for energy is growing. Traditional oil resources and fossil fuels are non-renewable, and their increased consumption will cause serious environmental problems, such as greenhouse effect and acid rain. Therefore, it is urgent to find clean and efficient new energy to meet energy demand.

[0003] Hydrogen, as a clean, non-toxic, high-calorific-value, renewable fuel, is considered one of the most promising energy carriers. However, to utilize hydrogen energy in industry, safe and efficient storage methods are needed. Current hydrogen storage methods mainly include solid hydrogen storage, gaseous hydrogen storage, and liquid hydrogen storage. Compared with other hydrogen storage technologies, solid hydrogen storage represented by hydrogen storage alloys is considered to be the most promising hydrogen storage method due to its safety, high hydrogen storage capacity, and recyclability.

[0004] TiFe alloy, a typical representative of AB type alloy, has attracted extensive attention from researchers due to its high hydrogen storage capacity (maximum hydrogen storage capacity ~1.86wt%), low cost and abundant resources. TiFe alloy can be used at room temperature and mild pressure, but the oxide layer on the surface of TiFe inhibits the further reaction of hydrogen, resulting in difficulty in activation. The hydrogen storage capacity at room temperature is not ideal, so it is necessary to use catalysts to improve the hydrogen release efficiency. However, although the existing catalysts can improve the hydrogen release efficiency, their reaction stability is difficult to control, and it is easy to react too fast in the early stage, resulting in a high platform pressure that is difficult to control, creating safety hazards, and significantly reducing the reaction in the later stage, which affects the hydrogen production efficiency. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a preparation method of an AB type hydrogen storage alloy and a hydrogen storage alloy. The technical problem to be solved by the present invention is achieved by the following technical solutions:

[0006] A method for preparing an AB type hydrogen storage alloy comprises:

[0007] Step 1, providing alloy raw materials according to a preset mass ratio, and providing a reaction metal sample according to the alloy raw materials;

[0008] Step 2, placing the reaction metal sample in a smelting furnace for multiple smelting to obtain a cast alloy sample;

[0009] Step 3, crushing and ball-milling the as-cast alloy sample after surface treatment to form an alloy powder sample, and dividing the alloy powder sample into three equal parts;

[0010] Step 4, mixing each of the alloy powder samples with one-dimensional graphene, two-dimensional graphene, and three-dimensional graphene of the same mass, respectively, to obtain a first mixed alloy sample, a second mixed alloy sample, and a third mixed alloy sample;

[0011] Step 5, placing the first mixed alloy sample, the second mixed alloy sample, and the third mixed alloy sample in a hydrogen storage tank for dehydrogenation, collecting a preset number of dehydrogenation time and dehydrogenation rate values ​​within the start collection time and the end collection time, and fitting the dehydrogenation time and the dehydrogenation rate values ​​with the dehydrogenation time as the horizontal axis and the dehydrogenation rate as the vertical axis to obtain a first dehydrogenation fitting curve, a second dehydrogenation fitting curve, and a third dehydrogenation fitting curve;

[0012] Step 6, taking the time corresponding to the maximum value of the hydrogen desorption rate value in the hydrogen desorption fitting curve as the dividing line, calculating the ratio of the area from the start collection time to the time corresponding to the maximum value to the area from the time corresponding to the maximum value to the end collection time, and obtaining the first parameter, the second parameter, and the third parameter in turn according to the first hydrogen desorption fitting curve, the second hydrogen desorption fitting curve, and the third hydrogen desorption fitting curve;

[0013] Step 7, normalizing the first parameter, the second parameter, and the third parameter, and configuring one-dimensional graphene, two-dimensional graphene, and three-dimensional graphene according to the normalized ratio to form a graphene catalyst;

[0014] Step 8: mixing the graphene catalyst with alloy powder formed by alloy raw materials.

[0015] In a specific embodiment, the step 2 comprises:

[0016] The reaction metal is repeatedly melted 3-6 times by vacuum arc melting to obtain a cast alloy sample with a chemical formula of TixFeyM.

[0017] In a specific embodiment, the step 2 specifically includes:

[0018] Step 21, open the door of the vacuum arc melting furnace, place the reaction metal sample in the crucible, and adjust it to a distance of 2 mm to 3 mm from the tungsten electrode;

[0019] Step 22, after cleaning the internal environment of the smelting furnace, adjust the pressure in the smelting furnace to 0.01Mpa and perform smelting 3-6 times;

[0020] Step 23: Grind the obtained alloy ingot to remove the oxide layer, wash it with anhydrous ethanol and dry it to obtain a cast alloy sample with a chemical formula of TixFeyM.

[0021] In a specific embodiment, M is one or more of Mn, Cu, Zr, Co, Ni, Al, Mg, Y, Ce, La, and Nb.

[0022] In a specific embodiment, M is Mn, Cu, La and Y.

[0023] In a specific embodiment, the reaction metal sample is weighed according to mass percentage, wherein 20-40 g of titanium metal, 20-40 g of iron metal, 10-20 g of manganese metal, 1-3 g of copper metal, 1-4 g of yttrium metal, and 1-5 g of lanthanum metal.

[0024] In a specific embodiment, the step 3 comprises:

[0025] Step 31, grinding the surface of the as-cast alloy sample with sandpaper to remove the oxide layer on the surface, cleaning the surface of the as-cast alloy sample with anhydrous ethanol after grinding, drying it in a vacuum drying oven, and then crushing the as-cast alloy sample by mechanical crushing;

[0026] Step 32: Under an inert atmosphere, the as-cast alloy sample obtained in step 31 is ball-milled, and the obtained powder is sieved through a 200-mesh sieve to form an alloy powder sample;

[0027] Step 33: Divide the alloy powder sample into three equal parts.

[0028] In one specific embodiment, step 32 specifically includes: using a QM-3SP2 planetary ball mill to mix the raw materials. The speed of the ball mill is 200-400 r / min, the ball-to-material ratio is 35:1, the ball milling time is 3 hours, and the direction of the ball mill is changed every 0.5 hours to ensure that the raw materials are mixed evenly.

[0029] In one embodiment, step 8 includes:

[0030] The alloy powder formed by the graphene catalyst and the alloy raw material is ball-milled in a planetary ball mill, the rotation speed of the ball mill is 200-400 r / min, the ball-to-material ratio is 20:1, the ball-milling time is 10-30 min, and the direction of the ball mill is changed every 5 min.

[0031] The invention also discloses an AB type hydrogen storage alloy, which is prepared by the preparation method of the AB type hydrogen storage alloy.

[0032] Beneficial effects of the present invention:

[0033] The preparation method of the AB type hydrogen storage alloy of the present invention analyzes the combination and reaction of the catalyst on one-dimensional, two-dimensional and three-dimensional graphene loads, determines the optimal parameters of the three, and mixes the three according to the optimal parameters to form a graphene catalyst, thereby slowing down the initial hydrogen release rate and improving the platform pressure of the AB type hydrogen storage alloy to 3-5 atmospheres, so that the hydrogen release rate can be maintained at a high level for a long time, thereby improving stability.

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic flow chart of a method for preparing an AB type hydrogen storage alloy provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0037] Embodiment 1

[0038] See also Figure 1 , Figure 1 The present invention provides a method for preparing an AB type hydrogen storage alloy, which comprises:

[0039] Step 1, providing alloy raw materials according to a preset mass ratio, and providing a reaction metal sample according to the alloy raw materials;

[0040] Wherein, the reaction metal sample includes rare earth elements and alloys such as Ti, Fe, Mn, Cu, Zr, Co, Ni, Al, Mg, Y, Ce, La, and Nb. An alloy with a chemical formula of TixFeyM is finally formed. The Cu element can form a secondary phase with the Y element to increase the hydrogen storage capacity. The rare earth elements Y and La can accelerate the reaction between the alloy and hydrogen, thereby improving the hydrogenation kinetics of the alloy and improving the activation and kinetic properties. Preferably, M is Mn, Cu, La, and Y. In this embodiment, the reaction metal sample is weighed by mass percentage, wherein 20-40g of metal titanium, 20-40g of metal iron, 10-20g of metal manganese, 1-3g of metal copper, 1-4g of metal yttrium, and 1-5g of metal lanthanum.

[0041] Step 2, placing the reaction metal sample in a smelting furnace for multiple smelting to obtain a cast alloy sample;

[0042] In specific implementation, open the door of the vacuum arc melting furnace, put the metal into the crucible, adjust the position of the tungsten electrode by adjusting the control rod so that it is above the crucible, and then rotate the lifting hand wheel to lower the tungsten electrode to 2mm-3mm above the metal. Close the furnace door and lock the fastening nut. Open the vacuum pump and the baffle valve in turn to evacuate the melting furnace, open the air inlet valve, and evacuate the entire system. When the vacuum reaches the required level, close the air inlet valve, close the baffle valve, open the valve of the argon gas bottle, maintain the pressure at about 0.05Mpa, then open the air inlet valve, fill the melting furnace with argon, and keep an eye on the barometer. When the atmospheric pressure level is reached, the air inlet valve must be closed immediately, and then the baffle valve must be closed to draw vacuum again, that is, to clean the melting furnace. This cleaning operation can be performed multiple times to ensure that the furnace environment is clean. After the cleaning is completed, close the baffle valve first, then turn off the vacuum pump, open the air inlet valve, and when the melting furnace reaches 0.01Mpa, immediately close the air inlet valve, turn on the water cooler, turn on the power switch of the argon arc welding machine, observe the melting furnace through the dimmer on the front observation window, and press the arc start button (the current should be the minimum at this time), and then adjust the current according to the actual situation. During smelting, the relative position of the tungsten electrode can be slightly adjusted to ensure that the metal in the crucible can be completely melted. The smelting time should be controlled within 20 seconds, and the pressure value of the barometer should be observed. If the pressure is close to full, the vent valve should be opened immediately to ensure safe operation. In order to ensure uniform alloy composition, the metal can be turned over by a manipulator and smelted repeatedly for 3-6 times. After smelting, turn off the argon arc welding machine and the argon gas bottle valve. After the metal is completely cooled (about 20 minutes), turn off the water cooler, open the vent valve, loosen the furnace door fastening nut after the barometer returns to zero, open the furnace door, and take out the button-type alloy ingot. Grind the surface of the alloy with sandpaper to remove the oxide layer on the surface. After grinding, clean it with anhydrous ethanol, dry it, and then crush the alloy mechanically.

[0043] Step 3, crushing and ball-milling the as-cast alloy sample after surface treatment to form an alloy powder sample, and dividing the alloy powder sample into three equal parts;

[0044] Specifically comprising: step 31, grinding the surface of the as-cast alloy sample with sandpaper to remove the oxide layer on the surface, cleaning the surface of the as-cast alloy sample with anhydrous ethanol after grinding, drying it in a vacuum drying oven, and then crushing the as-cast alloy sample by mechanical crushing;

[0045] Step 32: Under an inert atmosphere, the as-cast alloy sample obtained in step 31 is ball-milled, and the obtained powder is sieved through a 200-mesh sieve to form an alloy powder sample;

[0046] Step 33: Divide the alloy powder sample into three equal parts.

[0047] Preferably, a QM-3SP2 planetary ball mill can be used to mix the raw materials. The speed of the ball mill is 200 r / min, the ball-to-material ratio is 40:1, the ball milling time is 2 hours, and the direction of the ball mill is changed every 0.2 hours to ensure that the raw materials are mixed evenly.

[0048] Step 4, mixing each of the alloy powder samples with one-dimensional graphene, two-dimensional graphene, and three-dimensional graphene of the same mass, respectively, to obtain a first mixed alloy sample, a second mixed alloy sample, and a third mixed alloy sample; in order to ensure that the fitting curve parameter levels obtained subsequently are consistent, it is necessary to ensure that the mass of each alloy powder sample is the same;

[0049] Step 5, placing the first mixed alloy sample, the second mixed alloy sample, and the third mixed alloy sample in a hydrogen storage tank for dehydrogenation, collecting a preset number of dehydrogenation time and dehydrogenation rate values ​​within the start collection time and the end collection time, and fitting the dehydrogenation time and the dehydrogenation rate values ​​with the dehydrogenation time as the horizontal axis and the dehydrogenation rate as the vertical axis to obtain a first dehydrogenation fitting curve, a second dehydrogenation fitting curve, and a third dehydrogenation fitting curve;

[0050] It should be noted that, since the mass of the alloy powder is the same, theoretically the hydrogen release amounts of the three are the same, that is, the areas enclosed by the first hydrogen release fitting curve, the second hydrogen release fitting curve, and the third hydrogen release fitting curve are theoretically consistent, but since it is generally necessary to control the hydrogen release flow rate in actual production applications, and the curve in the later stage of the reaction is too smooth, therefore, in this embodiment, only the first 20 minutes are selected for statistics, that is, the end collection time is the 20th minute; in addition, the initial rising curve of the reaction is too steep, therefore, in this embodiment, the reaction parameters of 1-20 minutes are selected for statistics, that is, the starting collection time is the 1st minute; 4 records are recorded per minute, that is, 76 hydrogen release times are counted and the hydrogen release rate value is used for curve fitting.

[0051] Step 6, taking the time corresponding to the maximum value of the hydrogen desorption rate value in the hydrogen desorption fitting curve as the dividing line, calculating the ratio of the area from the start collection time to the time corresponding to the maximum value to the area from the time corresponding to the maximum value to the end collection time, and obtaining the first parameter, the second parameter, and the third parameter in turn according to the first hydrogen desorption fitting curve, the second hydrogen desorption fitting curve, and the third hydrogen desorption fitting curve;

[0052] Step 7, normalizing the first parameter, the second parameter, and the third parameter, and configuring one-dimensional graphene, two-dimensional graphene, and three-dimensional graphene according to the normalized ratio to form a graphene catalyst;

[0053] Step 8: mixing the graphene catalyst with alloy powder formed by alloy raw materials.

[0054] Preferably, the alloy powder formed by the graphene catalyst and the alloy raw material is ball-milled in a planetary ball mill, the rotation speed of the ball mill is 200-400 r / min, the ball-to-material ratio is 20:1, the ball milling time is 10-30 min, and the direction of the ball mill is changed every 5 min.

[0055] This embodiment analyzes the combination and reaction of the catalyst on one-dimensional, two-dimensional, and three-dimensional graphene loads, determines the optimal parameters of the three, and mixes the three according to the optimal parameters to form a graphene catalyst, thereby slowing down the initial hydrogen release rate and improving the platform pressure of the AB type hydrogen storage alloy to 3-5 atmospheres, so that the hydrogen release rate can be maintained at a high level for a long time, thereby improving stability.

[0056] This embodiment also discloses an AB type hydrogen storage alloy, which is prepared by the above-mentioned preparation method of the AB type hydrogen storage alloy.

[0057] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0058] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0059] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in a claim. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0060] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A method for preparing an AB type hydrogen storage alloy, characterized in that: include: Step 1, providing alloy raw materials according to a preset mass ratio, and providing a reaction metal sample according to the alloy raw materials; Step 2, placing the reaction metal sample in a smelting furnace for multiple smelting to obtain a cast alloy sample; Step 3, crushing and ball-milling the as-cast alloy sample after surface treatment to form an alloy powder sample, and dividing the alloy powder sample into three equal parts; Step 4, mixing the first alloy powder sample with one-dimensional graphene to obtain a first mixed alloy sample, mixing the second alloy powder sample with two-dimensional graphene to obtain a second mixed alloy sample, and mixing the third alloy powder sample with three-dimensional graphene to obtain a third mixed alloy sample, wherein the masses of the one-dimensional graphene, the two-dimensional graphene, and the three-dimensional graphene are all the same; Step 5, placing the first mixed alloy sample, the second mixed alloy sample, and the third mixed alloy sample in a hydrogen storage tank for dehydrogenation, collecting a preset number of dehydrogenation time and dehydrogenation rate values ​​within the start collection time and the end collection time, and fitting the dehydrogenation time and the dehydrogenation rate values ​​with the dehydrogenation time as the horizontal axis and the dehydrogenation rate as the vertical axis to obtain a first dehydrogenation fitting curve, a second dehydrogenation fitting curve, and a third dehydrogenation fitting curve; Step 6, taking the time corresponding to the maximum value of the hydrogen desorption rate value in the hydrogen desorption fitting curve as the dividing line, calculating the ratio of the area from the start time of collection to the time corresponding to the maximum value and the area from the time corresponding to the maximum value to the end time of collection, and obtaining the first parameter, the second parameter, and the third parameter in turn according to the ratio of the areas obtained from the first hydrogen desorption fitting curve, the second hydrogen desorption fitting curve, and the third hydrogen desorption fitting curve; Step 7, normalizing the first parameter, the second parameter, and the third parameter, and configuring one-dimensional graphene, two-dimensional graphene, and three-dimensional graphene according to the normalized ratio to form a graphene catalyst; Step 8, mixing the graphene catalyst with alloy powder formed by alloy raw materials; The step 2 comprises: The reaction metal sample was repeatedly melted 3-6 times by vacuum arc melting to obtain a chemical formula of Ti x Fe y As-cast alloy sample of M; The step 2 specifically includes: Step 21, open the door of the vacuum arc melting furnace, place the reaction metal sample in the crucible, and adjust it to a distance of 2 mm to 3 mm from the tungsten electrode; Step 22, after cleaning the internal environment of the smelting furnace, adjust the pressure in the smelting furnace to 0.01Mpa and perform smelting 3-6 times; Step 23: Grind the obtained alloy ingot to remove the oxide layer, wash it with anhydrous ethanol and dry it to obtain a chemical formula of Ti x Fe y As-cast alloy sample of M; M is one or more of Mn, Cu, Zr, Co, Ni, Al, Mg, Y, Ce, La, and Nb.

2. The method for preparing the AB type hydrogen storage alloy according to claim 1, characterized in that: M is Mn, Cu, La and Y.

3. The method for preparing the AB type hydrogen storage alloy according to claim 2, characterized in that: The reaction metal samples are weighed according to mass percentage, including 20-40g of titanium metal, 20-40g of iron metal, 10-20g of manganese metal, 1-3g of copper metal, 1-4g of yttrium metal, and 1-5g of lanthanum metal.

4. The method for preparing the AB type hydrogen storage alloy according to claim 1, characterized in that: The step 3 comprises: Step 31, grinding the surface of the as-cast alloy sample with sandpaper to remove the oxide layer on the surface, cleaning the surface of the as-cast alloy sample with anhydrous ethanol after grinding, drying it in a vacuum drying oven, and then crushing the as-cast alloy sample by mechanical crushing; Step 32: Under an inert atmosphere, the as-cast alloy sample obtained in step 31 is ball-milled, and the obtained powder is sieved through a 200-mesh sieve to form an alloy powder sample; Step 33: Divide the alloy powder sample into three equal parts.

5. The method for preparing the AB type hydrogen storage alloy according to claim 4, characterized in that: Step 32 is specifically as follows: the raw materials are mixed using a QM-3SP2 planetary ball mill, the speed of the ball mill is 200-400r / min, the ball-to-material ratio is 35:1, the ball milling time is 3h, and the direction of the ball mill is changed every 0.5h to ensure that the raw materials are mixed evenly.

6. The method for preparing the AB type hydrogen storage alloy according to claim 1, characterized in that: Step 8 includes: The alloy powder formed by the graphene catalyst and the alloy raw material is ball-milled in a planetary ball mill, the rotation speed of the ball mill is 200-400 r / min, the ball-to-material ratio is 20:1, the ball-milling time is 10-30 min, and the direction of the ball mill is changed every 5 min.

7. An AB type hydrogen storage alloy, characterized in that: The alloy is prepared by the preparation method of the AB type hydrogen storage alloy as described in any one of claims 1 to 6.

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