Low-temperature AB2 type hydrogen storage alloy as well as preparation method and application thereof

Abstract

The invention discloses a low-temperature AB2 type hydrogen storage alloy as well as a preparation method and application thereof, and relates to the technical field of hydrogen storage alloys. According to the low-temperature AB2 type hydrogen storage alloy, the YAl alloy with specific components and proportions is doped into the AB2 type hydrogen storage alloy, the low-temperature hydrogen desorption performance of a matrix is improved, the crystal structure of the obtained hydrogen storage alloy is a C14Laves phase, the lattice constant a is 0.48-0.49 nm, activation can be achieved at the low temperature of-40 DEG C or below, the hydrogen desorption plateau pressure of-40 DEG C is 0.1-1.0 MPa, and the hydrogen desorption performance of the low-temperature AB2 type hydrogen storage alloy is improved. The hydrogen storage capacity is guaranteed, and meanwhile the hydrogen desorption capacity can be improved to the maximum extent, so that the hydrogen storage capacity of the alloy at the temperature of minus 40 DEG C reaches 1.9 wt% or above, and the hydrogen desorption capacity also reaches 1.75 wt% or above.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen storage alloys, and in particular to a low-temperature AB2 type hydrogen storage alloy and a preparation method and application thereof. Background Art

[0002] Common hydrogen storage alloys include AB (TiFe series), AB5 (LaNi5 series), AB2 (TiMn2 series), A2B (Mg2Ni series), BCC (V series), etc. Among them, AB2 type hydrogen storage alloy is considered to be one of the most promising hydrogen storage alloys due to its high hydrogen storage capacity at room temperature, fast hydrogen absorption and desorption rate, and good cycle stability.

[0003] The hydrogen stored in hydrogen storage alloys can be converted into electrical energy through hydrogen fuel cells and other methods, so it can be used to solve the problem of energy shortage, especially the energy shortage in northwest my country. However, the climate conditions in northwest my country are relatively harsh, and the temperature is low in winter, which puts forward special requirements for the application of hydrogen storage alloy technology. The performance of traditional hydrogen storage materials may be affected under low temperature conditions, resulting in low efficiency of hydrogen storage and desorption or failure to work properly. Therefore, the research and development of hydrogen storage materials that can work efficiently under low temperature conditions is of great significance for energy storage and supply in the northwest region. Although the existing research on AB2 type hydrogen storage alloys can improve their hydrogen absorption and desorption capacity, it is also aimed at the hydrogen absorption and desorption capacity of the alloy at room temperature. Directly using the existing AB2 type hydrogen storage alloy in a low temperature environment will result in insufficient hydrogen desorption of the alloy due to the low pressure of its hydrogen desorption platform. How to regulate the structure of the alloy so that it can achieve hydrogen adsorption and desorption at a lower temperature is of great significance. Summary of the invention

[0004] In order to address the deficiencies in the prior art, the present invention provides a low-temperature AB2 type hydrogen storage alloy, in which a small amount of YAl alloy is doped into a TiMn2 series alloy matrix, thereby achieving the regulation of the lattice constant of the TiMn2 series alloy, thereby enabling the hydrogen decomposition platform pressure of the alloy to be increased to above 0.3 MPa at a low temperature of -40°C, and the low-temperature hydrogen decomposition amount is greatly improved.

[0005] Another object of the present invention is to provide a method for preparing a low-temperature AB2 type hydrogen storage alloy.

[0006] Another object of the present invention is to provide an application of a low-temperature AB2 type hydrogen storage alloy.

[0007] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0008] A low temperature AB2 type hydrogen storage alloy, wherein the low temperature AB2 type hydrogen storage alloy is Ti a Zr (1-a) Cr b Mn(2-b) M c , wherein 0.7≤a≤1, 0.5≤b≤1.5, 0.1≤c≤0.5; the M includes Y d Al (1-d) , where 0.2≤d≤0.3.

[0009] The alloy provided by the present invention is a YAl alloy added to the AB2 (TiMn2 system, in the present invention, the lattice site of the Ti alloy is replaced by a small amount of Zr, and the Mn alloy site is replaced by a small amount of Cr) alloy, and the alloy lattice constant is regulated by the substitution of the YAl intermediate alloy. In hydrogen storage alloys, the smaller the lattice constant, the higher the hydrogen release platform pressure, and the higher the hydrogen release amount at low temperature. However, if the platform pressure is too high, the hydrogen storage capacity will be reduced under a certain hydrogen absorption pressure. Therefore, the lattice constant of the hydrogen storage alloy should be reduced as much as possible to increase the hydrogen release platform pressure while ensuring the hydrogen absorption amount of the hydrogen storage alloy. In the present invention, YAl alloy is added to the AB2 alloy matrix, which can improve the hydrogen absorption and desorption platform pressure and hydrogen release capacity of the alloy under low temperature conditions without affecting the hydrogen storage performance of the alloy. At the same time, since the introduction of the Y element can reduce the thickness of the oxide film on the surface of the alloy, the present invention can also improve the low-temperature activation performance of the alloy, so that the alloy can be activated at a low temperature as low as -40°C. In the art, the activation temperature of hydrogen storage alloys is generally 200° C. If hydrogen storage and release is to be performed at low temperatures, the lower the activation temperature of the alloy, the more practical it is.

[0010] It should be noted that the reason why 0.7≤a≤1 and 0.5≤b≤1.5 are used in the present invention is to ensure that the alloy matrix itself has a certain hydrogen storage performance. If the amount of a or b is not within the above range, the basic hydrogen storage performance of the alloy will be greatly reduced. Even if YAl alloy is added for modification, the hydrogen storage performance of the obtained alloy will be insufficient.

[0011] Preferably, the crystal structure of the low-temperature AB2 type hydrogen storage alloy is C14 Laves phase.

[0012] More preferably, the lattice constant a of the low-temperature AB2-type hydrogen storage alloy is 0.48-0.49 nm.

[0013] More preferably, the lattice constant a of the low-temperature AB2-type hydrogen storage alloy is 0.482-0.485 nm.

[0014] Controlling the lattice constant a within the above range helps to obtain a more appropriate hydrogen desorption platform pressure.

[0015] Preferably, the activation temperature of the low-temperature AB2 type hydrogen storage alloy is ≤-40°C.

[0016] More preferably, the low-temperature AB2 type hydrogen storage alloy has a hydrogen desorption platform of 0.1 to 1.0 MPa at -40°C.

[0017] More preferably, the hydrogen desorption platform of the low-temperature AB2 type hydrogen storage alloy at -40°C is 0.3-0.6 MPa.

[0018] The present invention also protects a method for preparing a low-temperature AB2 type hydrogen storage alloy, comprising the following steps:

[0019] The low-temperature AB2 type hydrogen storage alloy is obtained by mixing raw materials according to the element ratio of the low-temperature AB2 type hydrogen storage alloy, melting and forming.

[0020] In a specific embodiment of the present invention, since Mn is volatile, a slight excess of Mn may be added when mixing the raw materials, for example, the actual amount of Mn added may exceed the theoretical amount by 3-8% (mass percentage).

[0021] In a specific embodiment of the present invention, the molding may include at least one of ingot molding and belt casting molding.

[0022] Preferably, the forming includes belt-swinging forming, and the power of the belt-swinging forming is 10-20kW.

[0023] In a specific embodiment of the present invention, the strip-spinning forming is performed in a vacuum strip-spinning furnace, and the vacuum strip-spinning furnace includes a crucible, a tundish and a copper roller.

[0024] More preferably, the time for the belt-swinging forming is 3 to 10 minutes.

[0025] More preferably, the linear speed of the belt-spinning forming is 5 to 20 m / s.

[0026] By regulating the belt-spinning smelting and belt-spinning speed, the slope factor of the alloy hydrogen release platform can be reduced and the composition uniformity can be increased, so that it has a higher hydrogen absorption and desorption capacity. Although the belt-spinning forming method is easy to form an oxide film on the alloy surface, resulting in poor activation performance of the alloy, the rare earth Y element doped in the present invention can reduce the thickness of the oxide film and improve the activation performance of the alloy.

[0027] In a specific embodiment of the present invention, the step of activation is further included after the molding. More specifically, the activation temperature is ≤-40° C. More specifically, the activation is performed under a hydrogen pressure of 5 MPa.

[0028] The present invention also protects the application of a low-temperature AB2 type hydrogen storage alloy in low-temperature hydrogen storage.

[0029] The low-temperature AB2 type hydrogen storage alloy provided by the present invention can be activated at low temperature (≤-40°C) and has excellent low-temperature hydrogen storage and desorption performance, so hydrogen energy storage can be achieved at low temperature.

[0030] Preferably, the temperature of the low-temperature hydrogen storage is ≤ 0°C.

[0031] More preferably, the temperature of the low-temperature hydrogen storage is ≤-40°C.

[0032] Preferably, the hydrogen pressure of the low-temperature hydrogen storage is 5 MPa.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The low-temperature AB2 type hydrogen storage alloy provided by the present invention can be activated at a low temperature below -40°C, with a lattice constant of 0.48-0.49nm and a hydrogen desorption platform pressure of 0.1-1.0MPa at -40°C. The hydrogen storage capacity can be maximized while ensuring the hydrogen desorption capacity. Therefore, the hydrogen storage capacity of the alloy at -40°C reaches more than 1.9wt%, and the hydrogen desorption capacity also reaches more than 1.75wt%. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The activation performance of the alloys obtained in Example 1 of the present invention and Comparative Example 1.

[0036] Figure 2 The hydrogen storage capacity and platform pressure of the alloys obtained in Example 1 of the present invention and Comparative Example 1. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with specific embodiments, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0038] Example 1

[0039] A low temperature AB2 type hydrogen storage alloy Ti 0.9 Zr 0.1 Cr1Mn1(Y 0.3 Al 0.7 ) 0.2 , the crystal structure is C14Laves phase;

[0040] The preparation method of the low-temperature AB2 type hydrogen storage alloy in this embodiment comprises the following steps:

[0041] The raw materials are mixed according to the element ratio in the composition of the low-temperature AB2 type hydrogen storage alloy (Ti, Zr, Cr, and Mn elements are introduced by adding metal single substances, and Y and Al elements are introduced by adding YAl alloy; the actual amount of Mn added is 5% more than the theoretical amount), smelted, formed, and activated at -40°C and a hydrogen pressure of 5MPa to obtain a low-temperature AB2 type hydrogen storage alloy;

[0042] The forming is belt-spinning forming with a power of 15 kW and a time of 5 minutes; the line speed of the belt-spinning forming is 15 m / s; and after forming, an alloy ingot with a thickness of 5 cm is obtained.

[0043] Example 2

[0044] A low temperature AB2 type hydrogen storage alloy, which is different from Example 1 only in that:

[0045] d = 0.22, that is, the low temperature AB2 type hydrogen storage alloy is Ti 0.9 Zr 0.1 Cr1Mn1(Y 0.22 Al 0.78 ) 0.2 .

[0046] The preparation method of the low-temperature AB2 type hydrogen storage alloy in this embodiment is consistent with that in Example 1.

[0047] Example 3

[0048] A low temperature AB2 type hydrogen storage alloy, which is different from Example 1 only in that:

[0049] d = 0.24, that is, the low temperature AB2 type hydrogen storage alloy is Ti 0.9 Zr 0.1 Cr1Mn1(Y 0.24 Al 0.76 ) 0.2 .

[0050] The preparation method of the low-temperature AB2 type hydrogen storage alloy in this embodiment is consistent with that in Example 1.

[0051] Example 4

[0052] A low temperature AB2 type hydrogen storage alloy, which is different from Example 1 only in that:

[0053] c = 0.3, d = 0.24, that is, the low temperature AB2 type hydrogen storage alloy is Ti 0.9 Zr 0.1 Cr1Mn1(Y 0.24 Al 0.76 ) 0.3 .

[0054] The preparation method of the low-temperature AB2 type hydrogen storage alloy in this embodiment is consistent with that in Example 1.

[0055] Example 5

[0056] A low temperature AB2 type hydrogen storage alloy, which is different from Example 1 only in that:

[0057] a=0.7, that is, the low temperature AB2 type hydrogen storage alloy is Ti 0.7 Zr 0.3 Cr1Mn1(Y 0.3 Al 0.7 ) 0.2 .

[0058] The preparation method of the low-temperature AB2 type hydrogen storage alloy in this embodiment is consistent with that in Example 1.

[0059] Example 6

[0060] A low temperature AB2 type hydrogen storage alloy, which is different from Example 1 only in that:

[0061] a=1, that is, the low temperature AB2 type hydrogen storage alloy is Ti1Cr1Mn1(Y 0.3 Al 0.7 ) 0.2 .

[0062] The preparation method of the low-temperature AB2 type hydrogen storage alloy in this embodiment is consistent with that in Example 1.

[0063] Example 7

[0064] A low temperature AB2 type hydrogen storage alloy, which is different from Example 1 only in that:

[0065] b = 0.5, that is, the low temperature AB2 type hydrogen storage alloy is Ti 0.9 Zr 0.1 Cr 0.5 Mn 1.5 (Y 0.3 Al 0.7 ) 0.2 .

[0066] The preparation method of the low-temperature AB2 type hydrogen storage alloy in this embodiment is consistent with that in Example 1.

[0067] Example 8

[0068] A low temperature AB2 type hydrogen storage alloy, which is different from Example 1 only in that:

[0069] b = 1.5, that is, the low temperature AB2 type hydrogen storage alloy is Ti 0.9 Zr 0.1 Cr 1.5Mn 0.5 (Y 0.3 Al 0.7 ) 0.2 .

[0070] The preparation method of the low-temperature AB2 type hydrogen storage alloy in this embodiment is consistent with that in Example 1.

[0071] Example 9

[0072] A low temperature AB2 type hydrogen storage alloy, which is different from Example 1 only in that:

[0073] c = 0.1, that is, the low temperature AB2 type hydrogen storage alloy is Ti 0.9 Zr 0.1 Cr1Mn1(Y 0.3 Al 0.7 ) 0.1 .

[0074] The preparation method of the low-temperature AB2 type hydrogen storage alloy in this embodiment is consistent with that in Example 1.

[0075] Example 10

[0076] A low temperature AB2 type hydrogen storage alloy, which is different from Example 1 only in that:

[0077] c = 0.5, that is, the low temperature AB2 type hydrogen storage alloy is Ti 0.9 Zr 0.1 Cr1Mn1(Y 0.3 Al 0.7 ) 0.5 .

[0078] The preparation method of the low-temperature AB2 type hydrogen storage alloy in this embodiment is consistent with that in Example 1.

[0079] Embodiment 11

[0080] A low-temperature AB2 type hydrogen storage alloy, the composition of the low-temperature AB2 type hydrogen storage alloy is consistent with that of Example 1, and the preparation method thereof is different from that of Example 1 only in that:

[0081] Replace belt casting with conventional ingot casting.

[0082] Comparative Example 1

[0083] An AB2 type hydrogen storage alloy, wherein c=0, that is, no YAl alloy is doped.

[0084] The preparation method of the AB2 type hydrogen storage alloy in this comparative example is consistent with that in Example 1.

[0085] Comparative Example 2

[0086] An AB2 type hydrogen storage alloy, in which d=1, that is, the doped YAl alloy is replaced by Y single substance.

[0087] The preparation method of the AB2 type hydrogen storage alloy in this comparative example is consistent with that in Example 1.

[0088] Comparative Example 3

[0089] An AB2 type hydrogen storage alloy, in which d=0, that is, the doped YAl alloy is replaced by Al single substance.

[0090] The preparation method of the AB2 type hydrogen storage alloy in this comparative example is consistent with that in Example 1.

[0091] Comparative Example 4

[0092] An AB2 type hydrogen storage alloy, wherein d=0.1.

[0093] The preparation method of the AB2 type hydrogen storage alloy in this comparative example is consistent with that in Example 1.

[0094] Comparative Example 5

[0095] An AB2 type hydrogen storage alloy, wherein d=0.4.

[0096] The preparation method of the AB2 type hydrogen storage alloy in this comparative example is consistent with that in Example 1.

[0097] Comparative Example 6

[0098] An AB2 type hydrogen storage alloy, wherein c=0.6.

[0099] The preparation method of the AB2 type hydrogen storage alloy in this comparative example is consistent with that in Example 1.

[0100] Comparative Example 7

[0101] An AB2 type hydrogen storage alloy, wherein c=0.02.

[0102] The preparation method of the AB2 type hydrogen storage alloy in this comparative example is consistent with that in Example 1.

[0103] Performance Testing

[0104] Lattice constant a test: The alloy sample is crushed and ground to obtain alloy powder, and the alloy powder is subjected to XRD ray diffraction and GSAS refinement to obtain the lattice constant a.

[0105] Low temperature (-40℃) hydrogen storage and discharge capacity test: Tested in accordance with national standard GB / T 33291-2016.

[0106] Low temperature (-40℃) hydrogen discharge platform pressure test: Tested in accordance with national standard GB / T 33291-2016.

[0107] The specific test data are shown in Table 1 below:

[0108] Table 1. Performance test data of alloys obtained from examples and comparative examples

[0109]

[0110]

[0111] According to the data in Table 1 above, it can be seen that the low-temperature AB2 type hydrogen storage alloy provided by the present invention can be activated at a low temperature below -40°C, the lattice constant is 0.48-0.49nm, the hydrogen storage capacity at -40°C reaches more than 1.9wt%, the hydrogen desorption capacity also reaches more than 1.75wt%, and the hydrogen desorption platform pressure at -40°C is 0.1-1.0MPa, which can maximize the hydrogen desorption capacity while ensuring the hydrogen storage capacity.

[0112] According to Examples 1 to 11, controlling the lattice constant a of the alloy to be 0.482 to 0.485 nm helps to obtain a more suitable hydrogen desorption platform pressure (0.3 to 0.6 MPa), under which the alloy can release the stored hydrogen more fully (Examples 1, 3 to 4, 7 to 8, 11).

[0113] According to the data comparison between Example 1 and Example 11 in Table 1, it can be seen that the use of the belt-spinning melting method can make the alloy have a higher hydrogen absorption and desorption capacity.

[0114] According to the data of Comparative Example 1 in Table 1, it can be seen that the alloy not doped with YAl, although its phase structure is still C14Laves phase, has a too large lattice constant of 0.495nm, which makes the platform pressure of the alloy too low and the effective hydrogen release amount less than 1.6wt%; at the same time, the strip melting will cause the formation of an oxide film on the surface of the alloy, resulting in a decrease in the activation performance of the alloy. Since Comparative Example 1 is not doped with Y element, the activation performance of the alloy is poor and cannot be activated at a low temperature of -40°C.

[0115] According to the data of Comparative Examples 2 to 3, it can be seen that when the YAl alloy is replaced by Y or Al, although the phase structure of the obtained alloy is still C14Laves phase, the lattice constant is inappropriate. In Comparative Example 2, since the doped YAl alloy is replaced by Y, the lattice constant is significantly increased to 0.501nm, which increases the hydrogen absorption capacity of the alloy, but the hydrogen desorption platform pressure is lower than 0.1MPa, and the effective hydrogen desorption capacity of the alloy is less than 0.5wt%. In Comparative Example 3, since the doped YAl alloy is replaced by Al, the lattice constant is reduced to 0.475nm, and the hydrogen absorption and desorption capacity of the alloy is significantly reduced, the hydrogen absorption capacity is less than 1.6wt%, and the hydrogen desorption capacity is less than 1.5wt%.

[0116] According to the data of Comparative Examples 4 to 5, a Zr (1-a) Cr b Mn (2-b) Inappropriate composition of the YAl alloy doped in the matrix will lead to inappropriate platform pressure of the resulting alloy; when the proportion of Y element in the YAl alloy is too small (Comparative Example 4), the platform pressure of the alloy is too high, the hydrogen absorption and desorption capacity of the alloy is significantly reduced, and the effective hydrogen desorption capacity is less than 1.6wt%; when the proportion of Y element in the YAl alloy is too large (Comparative Example 5), the platform pressure of the alloy is too low, the hydrogen desorption platform pressure is lower than 0.1MPa, and the effective hydrogen desorption capacity of the alloy is less than 0.9wt%.

[0117] According to the data of Comparative Examples 6 to 7, when Ti a Zr (1-a) Cr b Mn (2-b) If the amount of YAl alloy doped in the matrix is ​​not appropriate, it will also cause the platform pressure of the alloy to be too high or too low, which will lead to a decrease in the low-temperature hydrogen desorption capacity. When the amount of YAl doped is too much (Comparative Example 6), the platform pressure of the alloy is too high, the hydrogen absorption and desorption capacity of the alloy is significantly reduced, and the effective hydrogen desorption capacity is less than 1.2wt%; when the amount of YAl doped is too little (Comparative Example 7), the platform pressure of the alloy is too low, the hydrogen desorption platform pressure is lower than 0.1MPa, and the effective hydrogen desorption capacity of the alloy is less than 1.0wt%, which does not reflect the effect of YAl alloy doping.

[0118] 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 the scope of protection of the present invention. 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 essence and scope of the technical solution of the present invention.

Claims

1. A low temperature AB2 type hydrogen storage alloy, characterized in that: The low temperature AB2 type hydrogen storage alloy is Ti a Zr (1-a) Cr b Mn (2-b) M c , wherein 0.7≤a≤1, 0.5≤b≤1.5, 0.1≤c≤0.5; the M includes Y d Al (1-d) , where 0.2≤d≤0.

3.

2. The low temperature AB2 type hydrogen storage alloy according to claim 1, characterized in that: The crystal structure of the low-temperature AB2 type hydrogen storage alloy is C14 Laves phase.

3. The low temperature AB2 type hydrogen storage alloy according to claim 2, characterized in that: The lattice constant a of the low-temperature AB2 type hydrogen storage alloy is 0.48-0.49 nm.

4. The low temperature AB2 type hydrogen storage alloy according to claim 1, characterized in that: The activation temperature of the low-temperature AB2 type hydrogen storage alloy is ≤-40°C.

5. The low temperature AB2 type hydrogen storage alloy according to claim 4, characterized in that: The low-temperature AB2 type hydrogen storage alloy has a hydrogen release platform of 0.1 to 1.0 MPa at -40°C.

6. The method for preparing the low temperature AB2 type hydrogen storage alloy according to any one of claims 1 to 5, characterized in that: The steps include: The low-temperature AB2 type hydrogen storage alloy is obtained by mixing raw materials according to the element ratio of the low-temperature AB2 type hydrogen storage alloy, melting and forming.

7. The method for preparing the low temperature AB2 type hydrogen storage alloy according to claim 6, characterized in that: The forming includes belt-swinging forming, and the power of the belt-swinging forming is 10-20kW.

8. The method for preparing the low temperature AB2 type hydrogen storage alloy according to claim 7, characterized in that: The linear speed of the belt-spinning forming is 5-20 m / s.

9. Use of the low-temperature AB2 type hydrogen storage alloy according to any one of claims 1 to 5 in low-temperature hydrogen storage.

10. The use according to claim 9, characterized in that: The temperature of the low-temperature hydrogen storage is ≤0°C.

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