An overcharge-resistant AB5-type wide-temperature range nickel-hydrogen battery negative electrode material and a preparation method thereof

Abstract

The present invention discloses an overcharge-resistant AB5 type wide temperature range nickel-hydrogen battery negative electrode material and a preparation method thereof, and belongs to the technical field of nickel-hydrogen batteries and hydrogen storage materials. The AB5 type wide temperature range nickel-hydrogen battery negative electrode material includes an AB5 wide temperature range hydrogen storage alloy; the present invention performs induction melting of metal lanthanum, cerium, praseodymium, neodymium, zirconium, niobium, nickel, manganese and aluminum according to corresponding molar ratios, and homogenizes and anneals the ingot or sheet sample to obtain a Co-free overcharge-resistant AB5 type wide temperature range nickel-hydrogen battery negative electrode material. The AB5 wide temperature range hydrogen storage alloy includes a main phase CaCu5 structural phase and a niobium-rich phase. The doping of niobium element improves the corrosion resistance, pulverization resistance and hydrogen evolution overpotential of the alloy material, improves the overcharge resistance of the alloy electrode, and thus improves the wide temperature performance of the alloy electrode.

Description

Technical Field

[0001] The present invention belongs to the technical field of nickel-hydrogen battery and hydrogen storage material preparation, and particularly relates to an overcharge resistant AB 5 A wide temperature range nickel-hydrogen battery negative electrode material and a preparation method thereof. Background Art

[0002] Nickel-hydrogen batteries have the advantages of good safety, no pollution, low temperature, and excellent wide temperature performance. They have become one of the most promising "green energy" batteries and have been widely used in household electrical appliances, military aerospace and other fields.

[0003] Over the past 50 years, AB 5 The alloy electrode material has good electrocatalytic performance and excellent cycle stability due to its high Ni content. 5 Type alloys have been widely used in industry. In the past three decades, the rapid development of lithium-ion batteries has reduced the market share of nickel-hydrogen batteries, but nickel-hydrogen batteries have their unique advantages, including their safety performance and wide temperature performance. With the change of battery use environment, batteries are required to have excellent wide temperature performance. For example, the alarm of new energy vehicles requires the battery to have overcharge resistance and low-temperature discharge performance. Therefore, with the demand of the market, it is urgent to develop nickel-hydrogen battery negative electrode materials with excellent wide temperature performance. The negative electrode material of nickel-hydrogen battery has excellent wide temperature performance. Its negative electrode material must have a suitable platform pressure. A high platform will cause battery leakage, and a low platform pressure will cause the battery to be unable to discharge at low temperature. Therefore, it is more reasonable to choose a platform with atmospheric pressure. After ensuring the performance of low-temperature discharge at -20℃ or even -40℃, its cycle stability is improved by doping elements. So far, there is no literature or patent reporting on this new electrode material for Ni / MH batteries and its preparation method. Summary of the invention

[0004] In view of this, the object of the present invention is to provide an overcharge resistant AB 5 A negative electrode material for a wide temperature range nickel-hydrogen battery and a preparation method thereof. 5 The wide temperature hydrogen storage alloy contains the main phase CaCu 5 Structural phase and niobium-rich phase. The doping of niobium element improves the corrosion resistance, pulverization resistance and hydrogen evolution overpotential of the alloy material, improves the overcharge resistance of the alloy electrode, and thus improves the wide temperature performance of the alloy electrode.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides an overcharge resistant AB 5 Type wide temperature range nickel-hydrogen battery negative electrode material, characterized in that, in molar ratio, the AB 5 The general structural formula of wide temperature hydrogen storage alloy is: La0.36～0.62 Ce 0.29～0.51 Pr 0.014～0.037 Nd 0.044～ 0.112 Zr 0.020～0.022 Nb 0.004～0.1 Ni 4.38～4.55 Mn 0.35～0.38 Al 0.27～0.31 , wherein A = La, Ce, Pr, Nd, Zr, Nb, B = Ni, Mn, Al, and B / A = 5.0 to 5.3. The doping of niobium element in the negative electrode material improves the corrosion resistance, pulverization resistance and hydrogen evolution overpotential of the alloy material, improves the overcharge resistance of the alloy electrode, and thus improves the wide temperature performance of the alloy electrode.

[0007] Preferably, in the general structural formula, A is composed of lanthanum, cerium, praseodymium, neodymium, zirconium and niobium, B is composed of nickel, manganese and aluminum, and AB is 5 The wide temperature hydrogen storage alloy contains the main phase CaCu 5 structural phase and niobium-rich phase.

[0008] Preferably, the electrode sheet in the negative electrode material is composed of AB 5 The wide temperature hydrogen storage alloy powder and nickel powder are mixed evenly in a mass ratio of 0.5-2:3-5 and then pressed into tablets; the pressing pressure is 15-35MPa; the electrode sheet also includes foamed nickel wrapping the electrode sheet and a nickel-plated steel strip as a conductor.

[0009] The present invention provides a nickel-hydrogen battery negative electrode material according to the above technical solution, characterized in that the AB 5 The preparation method of the wide temperature range hydrogen storage alloy comprises the following steps:

[0010] (1) mixing metals lanthanum, cerium, praseodymium, neodymium, zirconium, niobium, nickel, manganese and aluminum in the molar ratios described in the above general structural formula and then performing vacuum induction melting;

[0011] (2) The alloy liquid smelted in step (1) is cast into an alloy ingot or spun into sheets to obtain AB 5 Wide temperature type hydrogen storage alloy, and then annealing treatment is performed.

[0012] Preferably, the vacuum degree of the vacuum induction melting in step (1) is 1-10 Pa, and the melting temperature is 1450-1550°C.

[0013] Preferably, the alloy ingot or sheet in step (2) is placed in a positive pressure argon atmosphere furnace for annealing at 950°C to 1120°C, specifically, the alloy ingot or sheet is heated to 500°C at room temperature, kept at a constant temperature for 30 minutes, then heated to 900°C, kept at a constant temperature for 30 minutes, then kept at a specified temperature in the range of 950°C to 1120°C for 5-24 hours, and then cooled to room temperature.

[0014] Preferably, the linear speed of the copper roller of the swing sheet in step (2) is 1.5-2.5 m / s, and the thickness of the swing sheet is 0.1-1 mm.

[0015] Preferably, the prepared AB 5 The wide temperature hydrogen storage alloy is subjected to air flow pulverization and sieving treatment in an inert atmosphere to obtain alloy powder with a particle size of D50=20-500um for making negative electrode materials for nickel-hydrogen batteries; the inert atmosphere is preferably argon or nitrogen.

[0016] Beneficial effects:

[0017] The present invention uses metal lanthanum, cerium, praseodymium, neodymium, zirconium, niobium, nickel, manganese and aluminum in a corresponding molar ratio for induction melting, and homogenizes and anneals the ingot or sheet sample to obtain AB 5 Wide temperature hydrogen storage alloy, and then the prepared AB 5 The wide temperature hydrogen storage alloy is subjected to air flow crushing and screening in an inert atmosphere to obtain AB with a particle size of D50 = 20 to 500 um. 5 Wide temperature type hydrogen storage alloy powder is mixed with nickel powder and pressed into sheets to make the negative electrode material electrode of nickel-hydrogen battery; in the present invention, since the negative electrode material is cobalt-free, the cost of the alloy material is reduced, and at the same time, the AB 5 The advantage of wide-temperature hydrogen storage alloys also lies in that the doping of niobium elements improves the corrosion resistance, pulverization resistance and hydrogen evolution overpotential of the alloy material, improves the overcharge resistance of the alloy electrode, and thus improves the wide-temperature performance of the alloy electrode.

[0018] The results of the embodiments show that the AB 5 After the electrode sheets were made of the wide-temperature hydrogen storage alloy, they were subjected to room-temperature overcharge resistance tests, high-temperature overcharge resistance tests and low-temperature performance tests. With the increase of Nb content and the optimization of annealing temperature, the overpotential increased from 329mV to 417mV, and the cycle stability of room-temperature overcharge cycle to 80% of the maximum capacity increased from 63 cycles to 160 cycles; the discharge capacity of 80 cycles at high temperature of 50°C increased from 82.3mAh / g to 138.9mAh / g; the ratio of the discharge capacity of the electrode sheet at low temperature of -20°C to the discharge capacity at -25°C was greater than 95.64%. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a process flow chart for preparing negative electrode materials for nickel-hydrogen batteries.

[0020] Figure 2 It is the XRD spectrum of the alloy electrode materials of Examples 5, 17, and 20.

[0021] Figure 3a and Figure 3b It is a graph of the pulverization performance of alloy electrode materials of Examples 5, 17, and 20.

[0022] Figure 4 It is the corrosion performance diagram of the alloy electrode materials of Examples 5, 17, and 20. DETAILED DESCRIPTION

[0023] The present invention provides an overcharge resistant AB 5 Type wide temperature range nickel-hydrogen battery negative electrode material, characterized in that, in molar ratio, the AB 5 The general structural formula of wide temperature hydrogen storage alloy is: La 0.36～0.62 Ce 0.29～0.51 Pr 0.014～0.037 Nd 0.044～ 0.112 Zr 0.020～0.022 Nb 0.004～0.1 Ni 4.38～4.55 Mn 0.35～0.38 Al 0.27～0.31 , wherein A = La, Ce, Pr, Nd, Zr, Nb, B = Ni, Mn, Al, and B / A = 5.0 to 5.3. The doping of niobium element in the negative electrode material improves the corrosion resistance, pulverization resistance and hydrogen evolution overpotential of the alloy material, improves the overcharge resistance of the alloy electrode, and thus improves the wide temperature performance of the alloy electrode.

[0024] In the present invention, in the general structural formula, A is composed of lanthanum, cerium, praseodymium, neodymium, zirconium and niobium, B is composed of nickel, manganese and aluminum, and AB 5 The wide temperature hydrogen storage alloy contains the main phase CaCu 5 structural phase and niobium-rich phase.

[0025] In the present invention, the electrode sheet in the negative electrode material is composed of AB 5 The wide temperature hydrogen storage alloy powder and nickel powder are mixed evenly in a mass ratio of 0.5-2:3-5 and then pressed into a sheet; the pressure of the sheeting is 15-35MPa; the electrode sheet also includes a nickel foam wrapped around the electrode sheet and a nickel-plated steel strip as a conductor. The present invention has no requirements on the sources of the nickel foam and the nickel-plated steel strip, and any commercially available product in the field can be used. The present invention does not limit the specific method of making the negative electrode material. In a specific embodiment, the present invention uses AB 5The wide-temperature hydrogen storage alloy and nickel powder are mixed evenly in proportion, poured into a mold, and pressed into an electrode sheet with a diameter of 10 mm at a pressure of 15 to 35 MPa. The electrode is wrapped with nickel foam and a nickel-plated steel strip is used as a wire to lead out.

[0026] The present invention also provides the AB 5 The preparation method of the wide temperature range hydrogen storage alloy comprises the following steps:

[0027] (1) mixing metals lanthanum, cerium, praseodymium, neodymium, zirconium, niobium, nickel, manganese and aluminum in the molar ratios described in the above general structural formula and then performing vacuum induction melting;

[0028] (2) The alloy liquid smelted in step (1) is cast into an alloy ingot or spun into sheets to obtain AB 5 Wide temperature type hydrogen storage alloy, and then annealing treatment is performed.

[0029] In the present invention, the vacuum degree of vacuum induction melting in step (1) is 1-10Pa, and the melting temperature is 1450-1550°C; the vacuum degree is preferably 1-6Pa, and the melting temperature is preferably 1470-1530°C, and more preferably 1500°C.

[0030] In the present invention, the alloy ingot or sheet in step (2) is placed in a positive pressure argon atmosphere furnace for annealing at 950°C to 1120°C, specifically, the alloy ingot or sheet is heated to 500°C at room temperature, kept at a constant temperature for 30 minutes, then heated to 900°C, kept at a constant temperature for 30 minutes, then kept at a specified temperature in the range of 950°C to 1120°C for 5-24 hours, and then cooled to room temperature. In some specific embodiments, the specific temperature of the alloy ingot of the present invention at the specified temperature for 5-24 hours is 1050°C, 1110°C, 1120°C, or 1180°C.

[0031] In the present invention, the linear speed of the copper roller of the sheet in step (2) is 1.5-2.5 m / s, and the sheet thickness is 0.1-1 mm. 5 The wide temperature type hydrogen storage alloy is subjected to air flow pulverization and screening treatment under an inert atmosphere to obtain alloy powder with a particle size D50=20-500um for preparing the negative electrode material of nickel-hydrogen batteries; preferably, an inert gas such as nitrogen or argon is used to exhaust oxygen to below 100ppm, and air flow pulverization and screening are performed at a pressure of 0.2-0.3MPa; the present invention has no limitation on the pulverizing mechanical equipment, and equipment known to those skilled in the art can be used.

[0032] In the present invention, an overcharge AB is provided. 5 The test method for the electrochemical performance of the negative electrode material of the wide temperature range nickel-hydrogen battery is as follows:

[0033] (1) Test system: A three-electrode system is used for testing. The reference electrode is a Hg / HgO electrode, the negative electrode (electrode to be tested) is a hydrogen storage alloy electrode to be tested, and the positive electrode (auxiliary electrode) is a sintered nickel hydroxide electrode with a capacity far in excess of the electrode to be tested.

[0034] (2) Room temperature cycle performance and rate performance test: Weigh 0.1g of hydrogen storage alloy powder and 0.4g of nickel powder in a mass ratio of 1:4, mix the hydrogen storage alloy powder and nickel powder evenly, pour them into a mold, and press them into an electrode sheet with a diameter of 10mm at a pressure of 20MPa. The electrode is wrapped with nickel foam and a nickel-plated steel strip is used as a wire to lead out. The connected sample is left to stand for 1h to achieve a complete infiltration effect. The activation process uses 60mAg -1 The activated samples were charged at a current density of 300 mA for 7 h and discharged at the same current density to 0.6 V vs Hg / HgO until the maximum capacity was reached. -1 Charge for 1.4h, discharge cut-off voltage 0.6V vsHg / HgO, cycle according to the above steps, when the discharge capacity is less than 80% of the maximum discharge capacity during the cycle, the number of charge and discharge cycles when the discharge capacity reaches 80% is regarded as the cycle life. -1 The cells were charged for 1.4 h and discharged at different discharge current densities to a cut-off voltage of 0.6 V vs Hg / HgO.

[0035] (3) Low temperature performance test: after activation at room temperature, the temperature is lowered from 25°C to -20°C, 60mAg -1 Charge for 7 hours and discharge to 0.5Vvs Hg / HgO at the same current density.

[0036] (4) High temperature overcharge resistance: after activation at room temperature, the temperature is raised from 25°C to 50°C, 300mA g -1 Charge for 1.4h and discharge to 0.6V vs Hg / HgO at the same current density.

[0037] (5) Overpotential test: The working electrode is a glassy carbon electrode with a diameter of 5 mm loaded with hydrogen storage alloy, the counter electrode is a graphite electrode, the reference electrode is a mercuric oxide electrode (Hg / HgO), and the electrolyte is 1M KOH. Weigh 8 mg of alloy powder and 2 mg of carbon black and disperse them in 700 μL, 250 μL of 98% ethanol and 50 μL of 5wt% Nafion solution, and ultrasonically disperse them to form a suspension. Then use a pipette to transfer 10 μL of the suspension and drop it onto the glassy carbon electrode. After natural drying to form a film, use linear sweep voltammetry (LSV) to test the overpotential at a current density of 10 mA cm -2 The potential at that time was converted to the overpotential of the standard hydrogen electrode for comparison of different materials.

[0038] The following is a description of an overcharge resistant AB provided by the present invention in combination with the embodiments. 5 The invention provides a detailed description of the negative electrode material for a wide temperature range nickel-hydrogen battery and its preparation method, but they should not be construed as limiting the scope of protection of the invention.

[0039] Examples 1 to 3

[0040] The molar ratio of 0.55La, 0.36Ce, 0.014Pr, 0.045Nd, 0.021Zr, 0.005Nb, 4.41Ni, 0.35Mn and 0.28Al was placed in a vacuum induction melting furnace, and after vacuum washing, argon was filled to a pressure of 0.05MPa. After complete melting, the molten metal was poured into a water-cooled ingot mold, cooled and taken out of the furnace to obtain an alloy ingot for annealing. The electrochemical properties of room temperature 25°C, high temperature 50°C overcharge resistance and -20°C are shown in Table 1.

[0041] Table 1

[0042]

[0043] From the data in Table 1, it can be seen that Examples 1 to 3 show the influence of different cooling methods on the properties of alloy materials. Rapid cooling is beneficial to the improvement of service life and the reduction of production cost.

[0044] Embodiments 4 to 9

[0045] The molar ratio of 0.46La, 0.42Ce, 0.025Pr, 0.078Nd, 0.021Zr, 0.004Nb, 4.43Ni, 0.36Mn and 0.29Al is placed in a vacuum induction melting furnace, and after vacuum washing, argon is filled to a pressure of 0.05MPa. After complete melting, the molten metal is poured into a water-cooled ingot mold or a sling to obtain an alloy ingot or a sling for annealing. The electrochemical properties of room temperature 25°C, high temperature 50°C overcharge resistance and -20°C are shown in Table 2.

[0046] Table 2

[0047]

[0048] From the data in Table 2, it can be seen that Examples 4 to 9 show the influence of different annealing temperatures on the properties of alloy materials. An increase in temperature is beneficial to an increase in lifespan, but exceeding a certain critical value is detrimental to lifespan.

[0049] Example 10

[0050] The molar ratio of 0.36La, 0.51Ce, 0.025Pr, 0.078Nd, 0.021Zr, 0.005Nb, 4.38Ni, 0.36Mn and 0.28Al was placed in a vacuum induction melting furnace, and after vacuum washing, argon was filled to a pressure of 0.05MPa. After complete melting, the molten metal was poured into a water-cooled ingot mold, and then taken out of the furnace after cooling to obtain an alloy ingot for annealing. The electrochemistry at room temperature 25°C, high temperature 50°C, overcharge resistance and -20°C is shown in Table 3.

[0051] Table 3

[0052]

[0053] From the data in Table 3, it can be seen that Example 10 shows that after reducing the La content, the platform rises, the capacity decreases, and the life is shortened.

[0054] Embodiment 11

[0055] The molar ratio of 0.46La, 0.37Ce, 0.037Pr, 0.112Nd, 0.020Zr, 0.006Nb, 4.44Ni, 0.36Mn and 0.29Al was placed in a vacuum induction melting furnace, and after vacuum washing, argon was filled to a pressure of 0.05MPa. After complete melting, the molten metal was poured into a water-cooled ingot mold, cooled and taken out of the furnace to obtain an alloy ingot for annealing. The electrochemistry at room temperature 25°C, high temperature 50°C, and -20°C is shown in Table 4.

[0056] Table 4

[0057]

[0058]

[0059] From the data in Table 4, it can be seen that Example 11 shows that the lifespan increases after increasing the Pr and Nd contents.

[0060] Example 12

[0061] The molar ratio of 0.61La, 0.29Ce, 0.015Pr, 0.044Nd, 0.022Zr, 0.008Nb, 4.55Ni, 0.38Mn and 0.31Al was placed in a vacuum induction melting furnace, and after vacuum washing, argon was filled to a pressure of 0.05MPa. After complete melting, the molten metal was poured into a water-cooled ingot mold, cooled and taken out of the furnace to obtain an alloy ingot for annealing. The electrochemistry at room temperature 25°C, high temperature 50°C overcharge resistance and -20°C is shown in Table 5.

[0062] Table 5

[0063]

[0064] From the data in Table 5, it can be seen that Example 12 shows that after increasing the Ni and Nb contents, the lifespan increases and the overpotential increases.

[0065] Embodiments 13 to 15

[0066] The mass fractions of 0.55La, 0.34Ce, 0.014Pr, 0.045Nd, 0.021Zr, 0.023Nb, 4.45Ni, 0.35Mn and 0.28Al were placed in a vacuum induction melting furnace, vacuumed and washed, and then filled with argon gas to a pressure of 0.05MPa. After complete melting, the molten metal was poured into a water-cooled ingot mold, cooled and taken out of the furnace to obtain an alloy ingot for annealing. The electrochemistry at room temperature 25°C, high temperature 50°C, overcharge resistance and -20°C is shown in Table 6.

[0067] Table 6

[0068]

[0069] As can be seen from Table 6, Examples 13 to 15 show that after increasing the Nb content, the lifespan increases, the overpotential increases, and the wide temperature performance improves.

[0070] Embodiments 16 to 18

[0071] The mass fractions of 0.46La, 0.37Ce, 0.027Pr, 0.076Nd, 0.021Zr, 0.05Nb, 4.41Ni, 0.36Mn and 0.28Al were placed in a vacuum induction melting furnace, vacuumed and washed, and then filled with argon gas to a pressure of 0.05MPa. After complete melting, the molten metal was poured into a water-cooled ingot mold, cooled and taken out of the furnace to obtain an alloy ingot for annealing. The electrochemistry at room temperature 25°C, high temperature 50°C, overcharge resistance and -20°C is shown in Table 7.

[0072] Table 7

[0073]

[0074] As shown in Table 7, Examples 16 to 18 show that after further increasing the Nb content, the lifespan increases, the overpotential increases, and the wide temperature performance improves.

[0075] Examples 19 to 21

[0076] The mass fractions of 0.46La, 0.32Ce, 0.027Pr, 0.076Nd, 0.021Zr, 0.1Nb, 4.41Ni, 0.36Mn and 0.28Al were placed in a vacuum induction melting furnace, vacuumed and washed, and then filled with argon gas to a pressure of 0.05MPa. After complete melting, the molten metal was poured into a water-cooled ingot mold, cooled and taken out of the furnace to obtain an alloy ingot for return processing. The electrochemical properties of room temperature 25℃, high temperature 50℃ overcharge resistance and -20℃ are shown in Table 8.

[0077] Table 8

[0078]

[0079]

[0080] As can be seen from Table 8, Examples 19 to 21 show that after further increasing the Nb content, the lifespan increases, the overpotential increases, and the wide temperature performance improves.

[0081] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An overcharge-resistant AB5 type wide temperature range nickel-hydrogen battery negative electrode material, characterized in that: The negative electrode material includes an AB5 wide temperature range hydrogen storage alloy; in molar ratio, the general structural formula of the AB5 wide temperature range hydrogen storage alloy is: La 0.36～0.62 Ce 0.29～ 0.51 Pr 0.014～0.037 Nd 0.044～0.112 Zr 0.020～0.022 Nb 0.004～0.1 Ni 4.38～4.55 Mn 0.35～0.38 Al 0.27～0.31 , wherein A=La, Ce, Pr, Nd, Zr, Nb, B=Ni, Mn, Al, B / A=5.0-5.

3. The doping of niobium element in the negative electrode material improves the corrosion resistance, pulverization resistance and hydrogen evolution overpotential of the alloy material, improves the overcharge resistance of the alloy electrode, and thus improves the wide temperature performance of the alloy electrode.

2. The negative electrode material for nickel-hydrogen batteries according to claim 1, characterized in that: The AB5 wide temperature range hydrogen storage alloy comprises a main phase CaCu5 structural phase and a niobium-rich phase.

3. The negative electrode material for nickel-hydrogen batteries according to claim 1, characterized in that: The alloy electrode is made by mixing AB5 wide temperature hydrogen storage alloy powder and nickel powder in a mass ratio of 0.5-2:3-5 and then pressing the mixture into sheets; the pressing pressure is 15-35 MPa; the alloy electrode also includes foamed nickel wrapping the electrode sheet and a nickel-plated steel strip as a conductor.

4. The negative electrode material for nickel-hydrogen batteries according to claim 1, characterized in that: The preparation method of the AB5 wide temperature range hydrogen storage alloy comprises the following steps: (1) La, cerium, praseodymium, neodymium, zirconium, niobium and nickel, manganese, aluminum 0.36～0.62 Ce 0.29～0.51 Pr 0.014～ 0.037 Nd 0.044～0.112 Zr 0.020～0.022 Nb 0.004～0.1 Ni 4.38～4.55 Mn 0.35～0.38 Al 0.27～0.31 After mixing the ingredients in the molar ratio described in the general formula, vacuum induction melting is performed; (2) The alloy liquid smelted in step (1) is cast into an alloy ingot or spun into sheets to obtain an AB5 wide temperature range hydrogen storage alloy, which is then annealed.

5. The negative electrode material for nickel-hydrogen batteries according to claim 4, characterized in that: The vacuum degree of the vacuum induction melting in step (1) is 1-10 Pa, and the melting temperature is 1450-1550°C.

6. The negative electrode material for nickel-hydrogen batteries according to claim 4, characterized in that: The alloy ingot or sheet in step (2) is placed in a positive pressure argon atmosphere furnace for annealing at 950°C to 1120°C, specifically, the alloy ingot or sheet is heated to 500°C at room temperature, kept at this temperature for 30 minutes, then heated to 900°C, kept at this temperature for 30 minutes, then kept at a specified temperature in the range of 950°C to 1120°C for 5-24 hours, and then cooled to room temperature.

7. The negative electrode material for nickel-hydrogen batteries according to claim 4, characterized in that: The copper roller linear speed of the swing sheet in step (2) is 1.5-2.5 m / s, and the thickness of the swing sheet is 0.1-1 mm.

8. The method for preparing the negative electrode material for nickel-hydrogen batteries according to any one of claims 1 to 7, characterized in that: The AB5 wide temperature hydrogen storage alloy is subjected to air flow pulverization and sieving treatment under an inert atmosphere to obtain alloy powder with a particle size of D50=20-500um for making a negative electrode material for a nickel-hydrogen battery.

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