Yttrium-nickel series hydrogen storage alloy and preparation method thereof

Abstract

The present invention discloses a yttrium-nickel hydrogen storage alloy and a preparation method thereof. The yttrium-nickel hydrogen storage alloy of the present invention has a composition shown in formula (I): RE x Y y Ni e Mn a Fe b Si c M d (I); wherein RE is selected from one or more of La, Ce, Pr, Nd, Sm and Gd, and M is selected from one or more of Al, Co, Cu, Zn and B; wherein 0.3≤x≤0.9, x+y=2, 0.05≤a≤0.5, 0.1≤b≤0.6, 0.005≤c≤0.3, 0.005≤d≤0.3, 6.9≤a+b+c+d+e≤7.1; x, y, a, b, c, d and e represent the molar fraction of each element respectively; wherein A in the yttrium-nickel hydrogen storage alloy is 2 B 7 The abundance of the phase is ≥95%. 2 B 7 The abundance of phase is high.

Description

Technical Field

[0001] The invention relates to a yttrium-nickel series hydrogen storage alloy and a preparation method thereof. Background Art

[0002] La-Mg-Ni series hydrogen storage alloy has a superlattice structure and can be used in self-discharge batteries. However, the alloy contains magnesium, which has a low melting point and is volatile. It is difficult to control its composition using vacuum induction melting. The fine magnesium powder volatilized during the preparation process is flammable and explosive, posing a safety hazard.

[0003] CN1148629A discloses a spherical hydrogen storage alloy powder, which is composed of MmNi u A x B y C z D w ; Wherein, Mm is mixed rare earth, A=Mn, Sn, V; B=Cr, Co, Ti, Nb, Zr, Zn, Si; C=Al, Mg, Ca; D=Li, Na, K; 1≤u≤5, 0≤x≤0.95, 0≤y≤1, 0≤z≤0.7, 0≤w≤0.9, 4.4≤u+x+y+z+w≤5.6. The spherical hydrogen storage alloy powder is not an A2B7 type hydrogen storage alloy.

[0004] CN115141943A discloses a Ti-Fe-Ni-Mn based hydrogen storage alloy, which is composed of titanium, iron, nickel, manganese and rare earth elements. Its chemical formula is: Ti 1.1 Fe 0.8-x Ni x Mn 0.2 +y wt.%RE. x is the atomic ratio, and 0≤x≤0.2, y is the mass percentage, and 0<y≤0.8%; RE is one of the rare earth elements lanthanum, cerium, praseodymium, neodymium, samarium, yttrium, and gadolinium. The hydrogen storage alloy is not an A2B7 type hydrogen storage alloy. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a yttrium-nickel hydrogen storage alloy, in which the abundance of the A2B7 phase is relatively high. Furthermore, the yttrium-nickel hydrogen storage alloy has a spherical or quasi-spherical microstructure. Furthermore, the yttrium-nickel hydrogen storage alloy has a relatively high electrochemical capacity and capacity retention rate. Another object of the present invention is to provide a method for preparing a yttrium-nickel hydrogen storage alloy, which method can increase the abundance of the A2B7 phase in the yttrium-nickel hydrogen storage alloy.

[0006] The above technical objectives are achieved through the following technical solutions.

[0007] In one aspect, the present invention provides a yttrium-nickel hydrogen storage alloy having a composition as shown in formula (I):

[0008] RE x Y y Ni e Mn a Fe b Si c M d (I);

[0009] Wherein, RE is selected from one or more of La, Ce, Pr, Nd, Sm and Gd, and M is selected from one or more of Al, Co, Cu, Zn and B;

[0010] Wherein, 0.3≤x≤0.9, x+y=2, 0.05≤a≤0.5, 0.1≤b≤0.6, 0.005≤c≤0.3, 0.005≤d≤0.3, 6.9≤a+b+c+d+e≤7.1; x, y, a, b, c, d and e represent the molar fraction of each element respectively;

[0011] The abundance of the A2B7 phase in the yttrium-nickel hydrogen storage alloy is ≥95%.

[0012] According to the yttrium-nickel series hydrogen storage alloy of the present invention, preferably, the abundance of the A2B7 phase in the yttrium-nickel series hydrogen storage alloy is ≥99%.

[0013] According to the yttrium-nickel hydrogen storage alloy of the present invention, preferably, the yttrium-nickel hydrogen storage alloy has a single A2B7 phase.

[0014] According to the yttrium-nickel series hydrogen storage alloy of the present invention, preferably, the yttrium-nickel series hydrogen storage alloy is in powder form and has a spherical or quasi-spherical microscopic morphology.

[0015] According to the yttrium-nickel series hydrogen storage alloy of the present invention, preferably, the yttrium-nickel series hydrogen storage alloy does not contain alkali metal elements and / or alkaline earth metal elements.

[0016] According to the yttrium-nickel series hydrogen storage alloy of the present invention, preferably, 1.1≤y≤1.7, 6≤e≤6.9.

[0017] According to the yttrium-nickel-based hydrogen storage alloy of the present invention, preferably, the RE necessarily contains La.

[0018] According to the yttrium-nickel hydrogen storage alloy of the present invention, preferably, the yttrium-nickel hydrogen storage alloy has a composition shown in one of the following:

[0019] (1)La 0.5 Y 1.5 Ni 6.55 Mn 0.1 Fe 0.2 Si 0.05 Al 0.05 ;

[0020] (2)La 0.5 Ce 0.1 Y 1.4 Ni 6.53 Mn 0.2 Fe 0.2 Si 0.02 Al 0.05 ;

[0021] (3)La 0.6 Y 1.4 Ni 6.2 Mn 0.3 Fe 0.3 Si 0.1 Co 0.1 ;

[0022] (4)La 0.4 Pr 0.2 Y 1.4 Ni 6.25 Mn 0.3 Fe 0.4 Si 0.05 Cu 0.05 ;

[0023] (5)La 0.5 Nd 0.2 Y 1.3 Ni 6.25 Mn 0.25 Fe 0.45 Si 0.1 Zn 0.05 ;

[0024] (6)La 0.5 Sm 0.1 Y 1.4 Ni 6.33 Mn 0.2 Fe 0.45 Si 0.05 B 0.02 .

[0025] On the other hand, the present invention provides a method for preparing the above-mentioned yttrium-nickel series hydrogen storage alloy, comprising the following steps:

[0026] (1) melting a raw material obtained according to the composition of a yttrium-nickel hydrogen storage alloy, and then refining it to obtain a molten liquid;

[0027] (2) placing a molten liquid in a container with a nozzle, allowing the molten liquid to pass through the nozzle, while introducing an inert gas into the nozzle, so that the molten liquid flowing down the nozzle forms spherical particles under the action of the inert gas flow; cooling the spherical particles to obtain alloy powder;

[0028] (3) The alloy powder is heat treated at a pressure of 0.1 Pa or less and a temperature of 750 to 950° C., and then forcedly cooled to 20 to 35° C. to obtain a yttrium-nickel hydrogen storage alloy.

[0029] According to the preparation method of the present invention, preferably, the pressure of the inert gas introduced into the nozzle is 1-10 MPa.

[0030] The yttrium-nickel hydrogen storage alloy of the present invention has a high abundance of A2B7 phase and a spherical or quasi-spherical microstructure. The yttrium-nickel hydrogen storage alloy of the present invention has a high electrochemical capacity and capacity retention rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a scanning electron microscope image of the yttrium-nickel hydrogen storage alloy obtained in Example 2.

[0032] Figure 2 This is a scanning electron microscope image of the yttrium-nickel hydrogen storage alloy obtained in Comparative Example 1.

[0033] Figure 3 This is the XRD diagram of the yttrium-nickel hydrogen storage alloy obtained in Example 2. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0035] <Yttrium Nickel Hydrogen Storage Alloy>

[0036] The yttrium-nickel hydrogen storage alloy of the present invention has a composition shown in formula (I):

[0037] RE x Y y Ni e Mn a Fe b Si c M d (I)

[0038] The yttrium-nickel hydrogen storage alloy of the present invention has a high abundance of the A2B7 phase. The abundance of the A2B7 phase may be greater than or equal to 95%; preferably, the abundance of the A2B7 phase is greater than or equal to 99%; more preferably, the yttrium-nickel hydrogen storage alloy has a single A2B7 phase. This is conducive to improving the electrochemical capacity and capacity retention rate of the hydrogen storage alloy.

[0039] The yttrium-nickel hydrogen storage alloy of the present invention can be in powder form, which is a spherical or quasi-spherical powder. The yttrium-nickel hydrogen storage alloy of the present invention has a spherical or quasi-spherical microscopic morphology. This is conducive to improving the abundance of the A2B7 phase, as well as the electrochemical capacity and capacity retention rate.

[0040] RE is selected from one or more of La, Ce, Pr, Nd, Sm and Gd. Preferably, RE must contain La. In some embodiments, RE is La. In other embodiments, RE consists of La and Mm; wherein Mm is selected from one or more of Ce, Pr, Nd, Sm and Gd. The molar ratio of La to Mm can be 5:(0.5-3); preferably 5:(1-2.5); more preferably 5:(1.5-2).

[0041] x represents the molar fraction of RE, 0.3≤x≤0.9; preferably, 0.5≤x≤0.7; more preferably, 0.6≤x≤0.65.

[0042] Y represents yttrium. y represents the molar fraction of Y. x+y=2. 1.1≤y≤1.7; preferably, 1.2≤y≤1.5; more preferably, 1.3≤y≤1.4.

[0043] Mn represents manganese. a represents the molar fraction of Mn. 0.05≤a≤0.5; preferably, 0.1≤a≤0.4; more preferably, 0.2≤a≤0.3.

[0044] Fe represents the iron element. b represents the molar fraction of Fe. 0.1≤b≤0.6; preferably, 0.2≤b≤0.5; more preferably, 0.3≤b≤0.4.

[0045] Si represents silicon element. c represents the molar fraction of Si. 0.005≤c≤0.3; preferably, 0.01≤c≤0.15; more preferably, 0.05≤c≤0.1.

[0046] M is selected from one or more of Al, Co, Cu, Zn, and B. In some embodiments, M is Zn. In other embodiments, M is Co. d represents the molar fraction of M. 0.005≤d≤0.3; preferably, 0.01≤d≤0.2; more preferably, 0.05≤d≤0.1.

[0047] Ni represents nickel element. e represents the molar fraction of Ni. 6.9≤a+b+c+d+e≤7.1; preferably, 6.95≤a+b+c+d+e≤7.05. 6≤e≤6.9; preferably, 6.2≤e≤6.6; more preferably, 6.3≤e≤6.5.

[0048] In certain embodiments, the yttrium nickel hydrogen storage alloy has a composition as shown in one of the following:

[0049] (1)La 0.5 Y 1.5 Ni 6.55 Mn 0.1 Fe 0.2 Si0.05 Al 0.05 ;

[0050] (2)La 0.5 Ce 0.1 Y 1.4 Ni 6.53 Mn 0.2 Fe 0.2 Si 0.02 Al 0.05 ;

[0051] (3)La 0.6 Y 1.4 Ni 6.2 Mn 0.3 Fe 0.3 Si 0.1 Co 0.1 ;

[0052] (4)La 0.4 Pr 0.2 Y 1.4 Ni 6.25 Mn 0.3 Fe 0.4 Si 0.05 Cu 0.05 ;

[0053] (5)La 0.5 Nd 0.2 Y 1.3 Ni 6.25 Mn 0.25 Fe 0.45 Si 0.1 Zn 0.05 ;

[0054] (6)La 0.5 Sm 0.1 Y 1.4 Ni 6.33 Mn 0.2 Fe 0.45 Si 0.05 B 0.02 .

[0055] Controlling the elemental composition and element content of the yttrium-nickel hydrogen storage alloy within the above range can increase its A2B7 phase abundance and also improve its electrochemical capacity and capacity retention rate.

[0056] <Method for preparing yttrium-nickel hydrogen storage alloy>

[0057] The preparation method of the yttrium-nickel hydrogen storage alloy of the present invention comprises the following steps: (1) a melting and refining step; (2) an atomization molding step; and (3) a post-processing step.

[0058] Melting and refining steps

[0059] A raw material having a composition of a yttrium-nickel-based hydrogen storage alloy is melted and then refined to obtain a molten liquid.

[0060] The raw material can be melted by heating. The heat source can be provided by a heating coil. The power of the heating coil can be 5-20 kW, preferably 10-18 kW, and more preferably 12-15 kW.

[0061] The raw materials may be melted in an inert gas atmosphere. Examples of inert gases include, but are not limited to, nitrogen, helium, neon, argon, krypton, and xenon.

[0062] The raw material can be heated and melted under a pressure of 0.02 to 0.08 MPa; preferably, the raw material is heated and melted under a pressure of 0.03 to 0.06 MPa; more preferably, the raw material is heated and melted under a pressure of 0.04 to 0.05 MPa.

[0063] Before melting the raw materials, the following steps may be performed: the raw materials obtained according to the composition of the hydrogen storage alloy are heated for a time of t4 under the conditions of a pressure of P1 and a power of the heating coil of W1, and then the power of the heating coil is adjusted to 0 kW. The reaction system is evacuated to a pressure of P2; and then an inert gas is filled into the reaction system to form the aforementioned melting atmosphere and pressure.

[0064] P1≤15Pa; preferably, P1≤10Pa; more preferably, P1≤5Pa.

[0065] W1 may be 2 to 12 kW, preferably 3 to 10 kW, and more preferably 4 to 7 kW. t4 may be 1 to 10 min, preferably 2 to 7 min, and more preferably 3 to 4 min.

[0066] P2≤15Pa; preferably, P2≤10Pa; more preferably, P2≤4Pa.

[0067] The power of the heating coil during refining may be 5 to 15 kW, preferably 7 to 12 kW, and more preferably 8 to 10 kW.

[0068] The refining time may be 2 to 15 minutes, preferably 4 to 10 minutes, and more preferably 5 to 7 minutes.

[0069] Atomization molding steps

[0070] The molten liquid is placed in a container with a nozzle, and the molten liquid is passed through the nozzle. At the same time, an inert gas is introduced into the nozzle. The molten liquid flowing down the nozzle forms spherical particles under the action of the inert gas flow; the spherical particles are cooled to obtain alloy powder.

[0071] Examples of inert gas include, but are not limited to, nitrogen, helium, neon, argon, krypton, and xenon. The pressure of the inert gas may be 1 to 10 MPa, preferably 3 to 8 MPa, and more preferably 4 to 7 MPa. This helps to increase the abundance of the A2B7 phase.

[0072] The molten liquid may be heated before passing through the nozzle. The power of the heating coil during heating may be 3 to 20 kW, preferably 5 to 15 kW, and more preferably 10 to 12 kW. The heating time may be 1 to 10 min, preferably 3 to 8 min, and more preferably 3 to 5 min.

[0073] The spherical particles can be cooled in a cooling tower.

[0074] Post-processing steps

[0075] The alloy powder is heat treated at a pressure of 0.1 Pa or less and a temperature of 750 to 950° C., and then forcedly cooled to 20 to 35° C. to obtain a yttrium-nickel hydrogen storage alloy. The heat treatment can be performed in a heat treatment furnace.

[0076] The heat treatment pressure is less than or equal to 0.1 Pa, preferably, less than or equal to 0.05 Pa, and more preferably, less than or equal to 0.03 Pa. This helps to increase the abundance of the A2B7 phase.

[0077] The heat treatment temperature is 750-950° C., preferably 850-950° C., and more preferably 870-930° C. This helps to increase the abundance of the A2B7 phase.

[0078] The heating rate from the initial temperature to the heat treatment temperature may be 5 to 20° C. / min, preferably 8 to 15° C. / min, and more preferably 10 to 12° C. / min.

[0079] The heat treatment time may be 5 to 19 hours, preferably 10 to 18 hours, and more preferably 14 to 17 hours, which helps to increase the abundance of the A2B7 phase.

[0080] The pressure condition for heat treatment can be formed by the following method: evacuate the reaction system to P5; then introduce inert gas to make the pressure of the reaction system P7; and then evacuate the reaction system to the heat treatment pressure.

[0081] P5 is less than or equal to 0.1Pa; preferably, less than or equal to 0.05Pa; more preferably, less than or equal to 0.03Pa.

[0082] Examples of inert gases include, but are not limited to, nitrogen, helium, neon, argon, krypton, and xenon. P7 may be 0.03 to 0.1 MPa, preferably 0.05 to 0.09 MPa, and more preferably 0.07 to 0.08 MPa.

[0083] The forced cooling method may be forced air cooling under the protection of an inert gas. This helps to increase the abundance of the A2B7 phase. Examples of inert gases include, but are not limited to, nitrogen, helium, neon, argon, krypton, and xenon.

[0084] The forced cooling time can be 2 to 10 hours; preferably 4 to 8 hours; more preferably 4 to 6 hours. The test method is described below:

[0085] Electrochemical capacity:

[0086] On the automatic charge and discharge tester, the activation and discharge specific capacity test parameters are set as follows: rest time 24h; charging current density 75mA / g, charging time 6h; rest time 10min after charging; discharge current density 75mA / g, discharge to a cutoff potential of -600mV relative to the Hg / HgO reference electrode; rest time 10min after discharge; 10 cycle test cycles. The maximum value of the discharge specific capacity is taken as the electrochemical capacity.

[0087] Capacity retention rate after 300 charge and discharge cycles:

[0088] After the hydrogen storage alloy electrode is activated, it is tested with an automatic charge and discharge tester, with the charge and discharge current density (IA) set to 300 mA / g, the charging time to 1.2 h, the stand time after charging to 10 min, the stand time after discharging to 10 min, and the cutoff potential relative to the Hg / HgO reference electrode to -600 mV. The cycle test is carried out 300 times under the above parameter conditions, and the ratio of the 300th discharge capacity to the maximum discharge capacity during the cycle is the capacity retention rate of 300 charge and discharge cycles.

[0089] Abundance of A2B7 phase and CaCu5 phase:

[0090] The samples were tested by X-ray diffractometer, and the phase structure and phase abundance were analyzed and fitted by jade, Fullprof and GSAS software.

[0091] Scanning electron microscopy:

[0092] The alloy powder was evenly sprinkled on the test bench with conductive glue, and then the loose powder was blown off with an ear bulb. After vacuuming, the microscopic morphology of the sample was observed.

[0093] In the following examples and comparative examples, the inert gas is argon.

[0094] The forced cooling method is forced air cooling under argon protection.

[0095] Examples 1 to 6

[0096] The raw material obtained according to the composition of the hydrogen storage alloy is heated for t4 time under the conditions of pressure P1 and heating coil power W1, and then the heating coil power is adjusted to 0kW. The reaction system is evacuated to a pressure of P2; then an inert gas is filled into the reaction system to make the pressure of the reaction system P3. The power of the heating coil is adjusted to W2 to completely melt the raw material; then the power of the heating coil is adjusted to W3 to refine for t1 time to obtain a molten liquid.

[0097] The molten liquid is placed in a tundish with a nozzle. The power of the heating coil of the tundish is adjusted to W4. After heating for t2 time, the molten liquid passes through the nozzle, and an inert gas with a pressure of P4 is introduced into the nozzle. Under the action of the inert gas flow, the molten liquid flowing down the nozzle forms spherical particles. The spherical particles are cooled in a cooling tower to obtain alloy powder.

[0098] The alloy powder is placed in a heat treatment furnace. The heat treatment furnace is evacuated to P5; then an inert gas is introduced to make the pressure in the heat treatment furnace 0.08 MPa; and the heat treatment furnace is evacuated to P6. The temperature of the heat treatment furnace is raised from room temperature to T, and kept at T for t3 time; then forced to cool to 25°C to obtain a yttrium-nickel hydrogen storage alloy.

[0099] The composition and properties of the hydrogen storage alloy are shown in Table 2. The specific parameters in the preparation process are shown in Table 1.

[0100] Table 1

[0101]

[0102] Comparative Example 1

[0103] The raw materials obtained according to the composition of the hydrogen storage alloy are placed in a smelting furnace. The smelting furnace is evacuated to below 5Pa; then an inert gas is filled into the smelting furnace to make the pressure in the smelting furnace reach 0.045MPa. The power of the heating coil is adjusted to 15kW to completely melt the raw materials; then the power of the heating coil is adjusted to 10kW and refined for 4 minutes to obtain a molten liquid.

[0104] The molten liquid is cooled by a rotating copper roller through which cooling water is passed, to obtain alloy flakes. The linear speed of the rotating copper roller is 3 to 5 m / s.

[0105] The alloy sheet is placed in a heat treatment furnace. The heat treatment furnace is evacuated to below 0.2Pa; then an inert gas is introduced to make the pressure in the heat treatment furnace 0.055MPa. The heat treatment furnace is heated from room temperature to 960℃ at a heating rate of 10℃ / min, and kept at 960℃ for 20h; then the furnace is cooled to 25℃ to obtain a heat-treated alloy sheet. The heat-treated alloy sheet is powdered by mechanical crushing to obtain a hydrogen storage alloy.

[0106] The composition of the hydrogen storage alloy is specifically shown in Table 2. The properties of the hydrogen storage alloy are shown in Table 2.

[0107] Table 2

[0108]

[0109] The present invention is not limited to the above-mentioned embodiments. Without departing from the essential content of the present invention, any deformation, improvement and substitution that can be conceived by those skilled in the art shall fall within the scope of the present invention.

Claims

1. A yttrium-nickel hydrogen storage alloy, It is characterized in that The yttrium-nickel hydrogen storage alloy has a formula (I) as shown in composition: RE x Y y Ni e Mr a Feb b Si c M d (I); Wherein, RE is selected from one or more of La, Ce, Pr, Nd, Sm and Gd, and M is selected from one or more of Al, Co, Cu, Zn and B; Wherein, 0.3≤x≤0.9, x+y=2, 0.1≤a≤0.4, 0.2≤b≤0.5, 0.01≤c≤0.15, 0.01≤d≤0.2, 6.2≤e≤6.6, 6.9≤a+b+c+d+e≤7.1; x, y, a, b, c, d and e represent the molar fraction of each element respectively; The yttrium-nickel hydrogen storage alloy has a single A 2 B 7 Phase; the yttrium-nickel hydrogen storage alloy is in powder form and has a spherical or quasi-spherical microscopic morphology.

2. The yttrium-nickel hydrogen storage alloy according to claim 1, It is characterized in that The yttrium-nickel hydrogen storage alloy does not contain alkali metal elements and / or alkaline earth metal elements.

3. The yttrium-nickel hydrogen storage alloy according to claim 1, It is characterized in that 1.1≤y≤1.7。 4. The yttrium-nickel hydrogen storage alloy according to claim 1, It is characterized in that The RE must contain La.

5. The yttrium-nickel hydrogen storage alloy according to any one of claims 1 to 4, It is characterized in that The yttrium-nickel hydrogen storage alloy has a composition shown in one of the following: (1)The 0.5 AND 1.5 Neither 6.55 Mn 0.1 Faith 0.2 Yeah 0.05 To the 0.05 ; <h2 style=";text-align:left;direction:ltr">(2)La<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> Ce<h2 style=";text-align:left;direction:ltr"> 0.1 <h2 style=";text-align:left;direction:ltr"> Y<h2 style=";text-align:left;direction:ltr"> 1.4 <h2 style=";text-align:left;direction:ltr"> Ni<h2 style=";text-align:left;direction:ltr"> 6.53 <h2 style=";text-align:left;direction:ltr"> Mn<h2 style=";text-align:left;direction:ltr"> 0.2 <h2 style=";text-align:left;direction:ltr"> Fe<h2 style=";text-align:left;direction:ltr"> 0.2 <h2 style=";text-align:left;direction:ltr"> Yes<h2 style=";text-align:left;direction:ltr"> 0.02 <h2 style=";text-align:left;direction:ltr"> Al<h2 style=";text-align:left;direction:ltr"> 0.05 <h2 style=";text-align:left;direction:ltr"> ; (3) Date 0.6 Y 1.4 Ni 6.2 Mr 0.3 Feb 0.3 Si 0.1 Co 0.1 ; (4) Date 0.4 Prof 0.2 Y 1.4 Ni 6.25 Mr 0.3 Feb 0.4 Si 0.05 Cu 0.05 ; (5)La 0.5 Sun 0.2 Y 1.3 No 6.25 Mn 0.25 Fe 0.45 Si 0.1 Zn 0.05 ; (6) Date 0.5 Sm 0.1 Y 1.4 Ni 6.33 Mr 0.2 Feb 0.45 Si 0.05 B 0.02 .

6. The method for preparing the yttrium-nickel hydrogen storage alloy according to any one of claims 1 to 5, It is characterized in that The steps include: (1) melting a raw material obtained according to the composition of a yttrium-nickel hydrogen storage alloy, and then refining it to obtain a molten liquid; (2) placing a molten liquid in a container with a nozzle, allowing the molten liquid to pass through the nozzle, while introducing an inert gas into the nozzle, so that the molten liquid flowing down the nozzle forms spherical particles under the action of the inert gas flow; Cooling the spherical particles to obtain alloy powder; (3) The alloy powder is heat treated at a pressure of 0.1 Pa or less and a temperature of 750 to 950° C., and then forcedly cooled to 20 to 35° C. to obtain a yttrium-nickel hydrogen storage alloy.

7. The preparation method according to claim 6, It is characterized in that The pressure of the inert gas introduced into the nozzle is 1 to 10 MPa.

Images