A method for preparing an intermetallic compound modified lithium ion battery anode material

Abstract

The application discloses a preparation method of intermetallic compound modified lithium ion battery negative electrode material. (96‑x) Ni4Fe x The method comprises the following steps: in the first step, Al, Ni and Fe ingots are melted into Al Ni4Fe x intermediate alloy ingots by using a vacuum arc melting furnace at 1650-1800 DEG C, and then a precursor strip is obtained by melt spraying; in the second step, the precursor strip is ball milled to obtain a precursor powder with a particle size of 1-3 microns; and in the third step, the precursor powder is immersed in a NaOH solution for 6-8 hours to obtain a Ni3Fe / Ni / NiO lithium ion battery negative electrode material. Compared with the previous material, the nano-porous oxide prepared by the application has higher porosity and larger specific surface area, and can more effectively alleviate the problem of the deterioration of electrochemical performance caused by the volume change of the active material in the charging and discharging process.

Description

Technical Field

[0001] This invention relates to the field of lithium-ion battery anode material technology, specifically a method for preparing an intermetallic compound modified lithium-ion battery anode material. Background Technology

[0002] Transition metal oxides (TMOs) are considered ideal anode materials for next-generation high-performance lithium-ion batteries due to their high theoretical capacity. Among them, NiO has attracted widespread attention due to its relatively high theoretical capacity, relatively low price, and non-polluting properties. The main problem facing NiO as a lithium-ion battery anode material is the rapid degradation of its electrochemical performance during battery cycling. This is primarily due to the large volume changes caused by the inherent conversion reactions, leading to the failure of the connection between the active material and the conductive current collector. Furthermore, due to NiO's semiconductor properties, it often exhibits slow reaction kinetics during operation. Introducing highly conductive modified components and designing and fabricating porous structures with large specific surface areas are effective measures to curb the rapid deterioration of the electrochemical performance of NiO-based lithium-ion batteries.

[0003] In the prior art, CN114649516A discloses a method for preparing lignin-carbon / nickel oxide nanocomposite materials. This method involves hydrothermal and high-temperature carbonization processes, resulting in a long production cycle. Furthermore, the sulfuric acid solution used in the preparation process poses environmental pollution and safety hazards, making it unsuitable for large-scale production. CN112436111A discloses a method for preparing graphene-modified nickel oxide nanocomposite materials. On the one hand, this method uses strong oxidants such as potassium permanganate, which poses a high risk in large-scale production. Additionally, the use of freeze-drying technology increases process costs. On the other hand, the prepared composite material has a low content of active nickel oxide, reducing its volumetric energy density. CN112436111A discloses a method for preparing a nickel oxide-graphene oxide hollow tubular composite material. The resulting material includes a hollow tubular nickel oxide layer and a carbon coating layer, and is applied to the negative electrode of a lithium-ion battery. The current material preparation process employs a bio-templating method and immersion pyrolysis, which are complex and have a long production cycle. Furthermore, the material prepared by this method has a large microstructure and small specific surface area, failing to provide sufficient buffer space to accommodate the adverse effects of electrode material volume changes. A paper published in the *International Journal of Energy Research*, 2022, 46, 24654 (DOI: 10.1002 / er.8711), discloses a one-step dealloying method for preparing porous Ni / NiO composite materials. This method involves etching an Al-Ni precursor alloy into a sodium hydroxide solution, simultaneously corroding aluminum and oxidizing nickel in situ to nickel oxide, resulting in a porous network structure Ni / NiO composite material. However, the material synthesized using this method has a low specific surface area when used as a lithium-ion battery anode, failing to effectively mitigate the adverse effects of electrode material volume changes. Additionally, the reaction kinetics of this anode material during lithiation-delithiation are slow, which does not meet the requirements of practical applications. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of current technologies by providing a method for preparing an intermetallic compound-modified lithium-ion battery anode material. This method is designed to... (The sentence is incomplete and requires further context to be fully translated.) (96-x) Ni4Fe xThe precursor (1≤x≤3, atomic percentage) contains an Al3Ni / Al eutectic structure and an Al9FeNi ternary alloy phase. After dealloying, a Ni / NiO porous nanowire framework and a uniformly distributed Ni3Fe intermetallic compound phase are derived, which can effectively improve the conductivity and the number of active sites of the material. In addition, the precursor strips are processed into micron-sized precursor powder with uniform composition by mechanical ball milling, thus ensuring that the final Ni3Fe / Ni / NiO composite material with an extremely fine structure is obtained, which increases the specific surface area of ​​the material. The nanoporous oxide prepared by this invention has higher porosity and larger specific surface area than previous materials, which can more effectively alleviate the problem of electrochemical performance deterioration caused by the volume change of active materials during charge and discharge.

[0005] The technical solution of this invention is:

[0006] A method for preparing an intermetallic compound modified lithium-ion battery anode material, the method comprising the following steps:

[0007] The first step is to prepare Al-Ni-Fe precursor strips.

[0008] First, Al, Ni, and Fe ingots are melted in a vacuum arc melting furnace at 1650~1800℃ to produce Al. (96-x) Ni4Fe x A master alloy ingot is prepared, wherein 1 ≤ x ≤ 3, and x is an atomic percentage. Subsequently, the master alloy ingot is remelted at 1650~1800℃ using the induction coil of a vacuum strip spinning machine. After being held in the molten state for 3~5 seconds, the melt is sprayed onto a copper wheel rotating at 30~40 m / s with a spray pressure difference of 0.8~1.0 MPa, resulting in a precursor strip with a thickness of 20~30 μm, a width of 2.0~3.0 mm, and a length of 60~120 cm.

[0009] The purity of the Al, Ni, and Fe ingots is 99.95 wt.%, by mass percentage.

[0010] The second step is to prepare Al-Ni-Fe precursor powder.

[0011] The precursor strips were ball-milled at 800-1000 r / min for 6-8 h using mechanical ball milling. The volume ratio of stainless steel grinding balls (2-5 mm in diameter) to the precursor strips was (10-20):1, resulting in precursor powder with a particle size of 1-3 μm.

[0012] The third step is to prepare Ni3Fe / Ni / NiO composite materials.

[0013] The precursor powder obtained in the second step is immersed in NaOH solution at 20~40℃ for 6~8 h for dealloying, then washed with ultrapure water 2~4 times, and then vacuum dried at 50~70℃ for 8~12 h to obtain Ni3Fe / Ni / NiO lithium-ion battery anode material.

[0014] In this process, 2-3 grams of precursor powder are added to every 300-500 ml of NaOH solution, and the concentration of the NaOH solution is 2.0-2.5 M; the resistivity of the ultrapure water is 18.2 MΩ•cm.

[0015] This lithium-ion battery anode material possesses a porous nanowire network structure with typical eutectic microstructure characteristics. The porous nanowires have an average diameter of 35–55 nm and contain secondary pore structures with an average pore diameter of 2–4 nm. The specific surface area of ​​the porous nanowires is 61–89 m². 2 / g, Ni3Fe intermetallic compounds are distributed in the Ni / NiO substrate.

[0016] The method described yields an intermetallic compound-modified lithium-ion battery anode material, which is used as a lithium-ion battery anode material.

[0017] The preparation method of the above-mentioned intermetallic compound modified nanoporous metal oxide lithium-ion battery anode material uses raw materials and equipment obtained through known means, and the operating process can be mastered by those skilled in the art.

[0018] The essential features of this invention are:

[0019] In terms of materials, firstly, the unique phase composition (Al3Ni / Al eutectic structure and Al9FeNi ternary alloy phase) in the precursor designed in this invention ensures that the Ni3Fe / Ni / NiO composite material prepared in this invention can form a unique porous nanowire network microstructure. This structure can release the internal stress generated during cycling along the axis of the nanowire skeleton, thereby improving cycling stability. Secondly, the microstructure of Ni / NiO-based anode materials prepared by current technology is relatively large, mostly above 200 nm, while the nanowire skeleton diameter of the material prepared in this invention is 35~55 nm, which can provide more buffer space to accommodate the volume change of the electrode material and enhance electrochemical stability. Thirdly, the formed porous network structure has a refined nanowire skeleton with abundant secondary pore structures, which can improve electrolyte permeability and accelerate lithium-ion transport kinetics. Fourthly, the introduced Ni3Fe intermetallic compound is uniformly distributed in the Ni / NiO substrate, which can effectively improve the conductivity of the material and the lithiation-delithiation reaction kinetics.

[0020] The essential features of this invention regarding the preparation method are as follows: First, in previous chemical synthesis methods, the micro-size of materials was uncontrollable, making it difficult to obtain uniform nanoscale materials. In contrast, this invention uses mechanical ball milling to fully refine and homogenize the precursor, ensuring that the final product forms a uniform nanoscale microstructure, increasing the material's specific surface area and the number of active sites. Second, the mechanical ball milling and dealloying processes used are simpler than previous hydrothermal methods and high-temperature sintering, requiring less complex equipment and production environments, resulting in lower process costs and making them more suitable for large-scale, batch production. Third, this invention does not require the use of precious metals, reducing raw material costs, and does not involve the use of toxic or harmful solutions, posing no health threat to operators or environmental pollution risks. Fourth, the in-situ introduction of Ni3Fe intermetallic compounds for modification via dealloying in a single step eliminates the need for additional process steps, significantly shortening the manufacturing cycle.

[0021] The beneficial effects of this invention are:

[0022] This invention prepares Al by melt spinning and mechanical ball milling. (96-x) Ni4Fe x (1≤x≤3) precursor powder was used to prepare Ni3Fe / Ni / NiO composite material through dealloying etching. This material has a unique porous nanowire network structure, enabling rapid lithium-ion transport, and is suitable as a negative electrode material for lithium-ion batteries. Specifically:

[0023] (1) This invention discloses a method for preparing an intermetallic compound modified lithium-ion battery anode material. The resulting Ni3Fe / Ni / NiO has a unique porous nanowire network structure, which can effectively buffer the volume change of the electrode material and achieve rapid ion and electron transport. This material has a performance of 200 mA g -1 After 100 charge-discharge cycles at a current density, it can still provide 870 mAh g. -1 The reversible capacity is comparable to the 697 mAh g⁻¹ of the Ni / NiO anode material in prior work (International Journal of Energy Research, 2022, 46, 24654. DOI: 10.1002 / er.8711). -1 Compared to the reversible capacity, the capacity is increased by 24%. Furthermore, compared to the 534 mA hg of the Ni-NiO-MoO2 / rGO nanocomposite material obtained in previous studies (Journal of Alloys and Compounds 2022, 926, 614-622. DOI:10.1016 / j.jallcom. 2022.166847), the capacity is significantly improved. -1With a reversible capacity 63% higher, it exhibits superior electrochemical performance and has greater application potential as a negative electrode material for lithium-ion batteries.

[0024] (2) The present invention discloses a method for preparing an intermetallic compound modified lithium-ion battery anode material. Precursor powder is prepared using ball milling technology, reducing the precursor size from a minimum of 20-30 μm in a single direction to 1-3 μm in all three directions. After dealloying, the product size obtained by previous techniques is typically above 200 nm, while the Ni3Fe / Ni / NiO prepared by the present invention has a unique porous nanowire microstructure. The nanowire framework diameter is only 35-55 nm, and the nanowire framework contains abundant secondary pore structures with pore diameters of 2-4 nm, resulting in a large specific surface area of ​​61-89 m². 2 g -1 This facilitates the rapid transfer of lithium ions and electrons, similar to the 53 μm of Ni / NiO anode material in previous work (International Journal of Energy Research, 2022, 46, 24654. DOI: 10.1002 / er.8711). 2 g -1 Compared to other materials, the specific surface area is increased by 15.1% to 67.9%. This structure provides sufficient free space to accommodate the volume expansion of the electrode material during charge and discharge, which is beneficial to improving cycle stability.

[0025] (3) The present invention provides a method for preparing a lithium-ion battery anode material modified by intermetallic compounds. In the obtained material, Ni3Fe intermetallic compounds are uniformly distributed in the Ni / NiO substrate, which can significantly improve the overall conductivity of the anode material, accelerate the redox reaction kinetics, and improve cycle stability.

[0026] (4) The present invention provides a method for preparing a lithium-ion battery anode material modified by intermetallic chemical reaction. The material preparation process employs processes such as melt spinning, mechanical ball milling, and dealloying. It does not involve the use of complex process equipment or the requirements of special production environments. The process is simple, the production cycle is short, and it is suitable for large-scale production.

[0027] (5) The present invention provides a method for preparing an intermetallic compound modified lithium-ion battery anode material. The production process does not involve the use of solutions that are harmful to the environment and operators, poses no health threat to operators, and does not pose an environmental pollution risk. At the same time, the preparation process does not require the use of expensive metal raw materials, which further reduces the production cost. Attached Figure Description

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] Figure 1 This is a scanning electron microscope image of the Ni3Fe / Ni / NiO composite material obtained in Example 1;

[0030] Figure 2 This is a transmission electron microscope image of the Ni3Fe / Ni / NiO composite material obtained in Example 1;

[0031] Figure 3 This is a high-resolution transmission electron microscope image of the Ni3Fe / Ni / NiO composite material obtained in Example 1;

[0032] Figure 4 The X-ray diffraction pattern of the Ni3Fe / Ni / NiO composite material obtained in Example 1;

[0033] Figure 5 The graph shows the cycle performance test results of the Ni3Fe / Ni / NiO composite material obtained in Example 1 as the negative electrode of a lithium-ion battery. Detailed Implementation

[0034] Example 1

[0035] The first step is to prepare Al-Ni-Fe precursor alloy strips.

[0036] First, Al, Ni, and Fe ingots (all with a purity of 99.95% by mass) were melted at 1700℃ using a vacuum arc melting furnace to produce Al. 95 Ni4Fe1 (atomic percentage) master alloy ingot; then, the master alloy ingot was remelted at 1700℃ by the induction coil of a vacuum strip spinning machine. After being held in the molten state for 4 seconds, the melt was sprayed onto a copper wheel rotating at 35 m / s with a spray pressure difference of 0.9 MPa, resulting in a precursor strip with a thickness of 25 μm, a width of 2.5 mm, and a length of 100 cm.

[0037] The second step is to prepare Al-Ni-Fe precursor alloy powder.

[0038] The precursor strips were ball-milled at 900 r / min for 7 h using mechanical ball milling. The volume ratio of stainless steel grinding balls (3 mm in diameter) to precursor strips was 15:1 (the volume of the strips was calculated from the product of the measured length, width and thickness), resulting in precursor powder with a particle size of 2 μm.

[0039] The third step is to prepare Ni3Fe / Ni / NiO composite materials.

[0040] 2.5 g of the precursor powder obtained in the second step was immersed in 400 ml of 2.2 M NaOH solution at 25 °C for 7 h for dealloying, then washed three times with ultrapure water, and then vacuum dried at 60 °C for 10 h to obtain Ni3Fe / Ni / NiO lithium-ion battery anode material.

[0041] The resistivity of the ultrapure water is 18.2 MΩ•cm.

[0042] Figure 1 , Figure 2 The images shown are scanning electron microscope (SEM) and transmission electron microscope (TEM) images of the Ni3Fe / Ni / NiO composite material prepared in Example 1. The porous nanowire network structure is clearly visible, with a nanowire framework diameter of 35 nm and abundant secondary pore structures with a pore diameter of 2 nm and a specific surface area of ​​89 m². 2 g -1 . Figure 3 The high-resolution transmission electron microscope image clearly shows that the lattice fringes correspond to Ni3Fe, Ni, and NiO, respectively, proving that the obtained material is a composite material composed of Ni3Fe, Ni, and NiO. Figure 4 The X-ray diffraction pattern of the material is shown, from which the diffraction peaks of the Ni3Fe phase can be clearly observed, further proving the successful introduction of the Ni3Fe intermetallic compound.

[0043] The Ni3Fe / Ni / NiO prepared in this embodiment was used as the negative electrode material to assemble lithium-ion batteries, and the electrochemical performance was tested using the following method:

[0044] Using Ni3Fe / Ni / NiO as the negative electrode material, lithium foil as the counter electrode, 1.0 M LiPF6 in ethyl carbonate-diethyl carbonate (volume ratio 1:1) as the electrolyte, and Celgard 2400 microporous polypropylene membrane as the battery separator, the battery was encapsulated in an argon-filled glove box (model CR2032). After the encapsulated battery was left to stand for 12 hours, its electrochemical performance was tested in a battery testing system at room temperature. Figure 5 The graph shows the cycle performance test results of the Ni3Fe / Ni / NiO assembled lithium-ion battery prepared in this embodiment. As can be seen from the graph, the assembled battery exhibits good cycle stability at 200 mA g. -1 At a current density, after 100 charge-discharge cycles, it exhibited 870 mAh g⁻¹. -1The reversible capacity is compared to the 697 mAh g⁻¹ of the Ni / NiO anode material in prior work (International Journal of Energy Research, 2022, 46, 24654. DOI: 10.1002 / er.8711). -1 Compared to the reversible capacity, the capacity increased by 24%, demonstrating that the introduction of the Ni3Fe phase can significantly improve electrochemical performance. Furthermore, compared to the 534 mAh g⁻¹ of the Ni-NiO-MoO₂ / rGO anode material obtained in previous studies (Journal of Alloys and Compounds 2022, 926, 614-622. DOI: 10.1016 / j.jallcom. 2022.166847), the capacity increased by 24%, proving that the introduction of the Ni3Fe phase can significantly improve electrochemical performance. -1 Its reversible capacity is 63% higher.

[0045] Example 2

[0046] The first step is to prepare Al-Ni-Fe precursor alloy strips.

[0047] First, Al, Ni, and Fe ingots (all with a purity of 99.95% by mass) were melted at 1800℃ in a vacuum arc melting furnace to produce Al. 94 Ni4Fe2 (atomic percentage) master alloy ingot; then, the master alloy ingot was remelted at 1800℃ by the induction coil of a vacuum strip spinning machine. After being held in the molten state for 3 seconds, the melt was sprayed onto a copper wheel rotating at 40 m / s with a spray pressure difference of 1.0 MPa, resulting in a precursor strip with a thickness of 20 μm, a width of 2.0 mm, and a length of 60 cm.

[0048] The second step is to prepare Al-Ni-Fe precursor alloy powder.

[0049] The precursor strips were ball-milled at 1000 r / min for 6 hours using mechanical ball milling. The volume ratio of stainless steel grinding balls (2 mm in diameter) to precursor strips was 20:1, resulting in precursor powder with a particle size of 1 μm.

[0050] The third step is to prepare Ni3Fe / Ni / NiO composite materials.

[0051] Three grams of the precursor powder obtained in the second step were immersed in 500 ml of 2.0 M NaOH solution at 40°C for 8 h for dealloying, then washed twice with ultrapure water, and then vacuum dried at 70°C for 8 h to obtain Ni3Fe / Ni / NiO lithium-ion battery anode material.

[0052] The resistivity of the ultrapure water is 18.2 MΩ•cm. The resulting Ni3Fe / Ni / NiO composite porous nanowire framework has a diameter of 55 nm, the secondary pore structure on the nanowire framework has a diameter of 4 nm, and the specific surface area is 61 m². 2 g -1 .

[0053] Example 3

[0054] The first step is to prepare Al-Ni-Fe precursor alloy strips.

[0055] First, Al, Ni, and Fe ingots (all with a purity of 99.95% by mass) were melted at 1650℃ using a vacuum arc melting furnace to produce Al. 93 Ni4Fe3 (atomic percentage) master alloy ingot; then, the master alloy ingot was remelted at 1650℃ by the induction coil of a vacuum strip spinning machine. After being held in the molten state for 5 seconds, the melt was sprayed onto a copper wheel rotating at 30 m / s with a spray pressure difference of 0.8 MPa, resulting in a precursor strip with a thickness of 30 μm, a width of 3.0 mm, and a length of 120 cm.

[0056] The second step is to prepare Al-Ni-Fe precursor alloy powder.

[0057] The precursor strips were ball-milled at 800 r / min for 8 h using mechanical ball milling. The volume ratio of stainless steel grinding balls (5 mm in diameter) to precursor strips was 10:1, resulting in precursor powder with a particle size of 3 μm.

[0058] The third step is the use of Ni3Fe / Ni / NiO composite materials.

[0059] Two grams of the precursor powder obtained in the second step were immersed in 300 ml of 2.5 M NaOH solution at 20°C for 6 h to dealloy, then washed 4 times with ultrapure water, and then vacuum dried at 50°C for 12 h to obtain Ni3Fe / Ni / NiO lithium-ion battery anode material.

[0060] The resistivity of the ultrapure water is 18.2 MΩ•cm. The resulting Ni3Fe / Ni / NiO composite porous nanowire framework has a diameter of 45 nm, the secondary pore structure on the nanowire framework has a diameter of 3 nm, and the specific surface area is 72 m². 2 g -1 .

[0061] Comparative Example 1: Choosing an atomic ratio of Al 80 Ni 15Fe5 alloy powder was used as a precursor for dealloying under the same conditions as in Example 1. Morphological characterization of the samples showed that no porous nanowire network structure was formed; only a porous ligament structure was obtained. The ligaments were relatively coarse, with a diameter more than three times that of the present invention. When used as a lithium-ion battery anode material, it exhibited poor electrochemical performance at 200 mA g. -1 The reversible capacity exhibited after 100 charge-discharge cycles at the current density is less than half that of Example 1.

[0062] Comparative Example 2: In the mechanical ball milling process, the ball milling speed was set to 300 r / min, and other conditions were the same as in Example 1. Morphological characterization results showed that the obtained material still possessed a porous nanowire network structure, but the nanowire framework size was larger, more than three times the diameter of that of the present invention, and no secondary pore structure was observed on the nanowire framework. When used as a lithium-ion battery anode material, it exhibited poor electrochemical performance at 200 mA g. -1 The reversible capacity exhibited after 100 charge-discharge cycles at the current density is less than 3 / 5 of that in Example 1.

[0063] Comparative Example 3: The temperature in the dealloying process was set to 70 °C, and other conditions were the same as in Example 1. Morphological characterization results showed that the obtained material still possessed a porous nanowire network structure, but the nanowire framework size was larger, with a diameter more than four times that of the present invention, and no secondary pore structure was observed on the nanowire framework. When used as a negative electrode material for lithium-ion batteries, it exhibited poor electrochemical performance at 200 mA g. -1 At the current density, the reversible capacity exhibited after 100 charge-discharge cycles is less than 3 / 5 of that in this embodiment.

[0064] In Comparative Example 1, the significantly reduced content of Al3Ni rod-like structures in the precursor resulted in the formation of only a porous ligament structure after dealloying. Due to the reduced Al content in the precursor, the resulting ligaments were relatively large and lacked secondary pore structures. Compared to Example 1, the specific surface area was smaller, and the number of surface active sites was reduced, failing to provide sufficient buffer space to accommodate volume changes in the electrode material, thus exhibiting poor electrochemical cycling stability. In Comparative Example 2, the reduced ball mill speed during mechanical ball milling prevented effective homogenization of the precursor, resulting in larger phase sizes in the precursor. This led to coarsening of the nanowire network framework in the dealloyed product, thereby affecting the electrochemical performance of the material. In Comparative Example 3, the increased dealloying temperature accelerated the migration rate of atoms at the solid-liquid interface during dealloying, resulting in a significantly larger nanowire network microstructure after dealloying. However, the reduced specific surface area made the material prone to cracking and structural damage during charge-discharge processes, ultimately affecting its cycling stability.

[0065] In summary, this invention, through continuous experimentation with vacuum arc melting, melt spinning, mechanical ball milling, and dealloying processes, and by strictly controlling the process parameters at each stage, finally achieves a Ni / NiO composite material with Ni3Fe intermetallic compound embedding through a sodium hydroxide solution for dealloying treatment. This material possesses a unique porous nanowire network structure with abundant secondary pore structures within the nanowire framework. Compared to previous materials, the nanoporous oxide prepared by this invention exhibits higher porosity and a larger specific surface area, effectively mitigating the electrochemical performance degradation caused by volume changes in the active material during charge and discharge. Simultaneously, the introduction of the Ni3Fe intermetallic compound improves the overall conductivity of the electrode material and accelerates reaction kinetics, demonstrating structural and performance advantages when used as a negative electrode material for lithium-ion batteries.

[0066] Matters not covered in this invention are common knowledge.

Claims

1. A method of preparing an intermetallic compound-modified lithium-ion battery anode material, The method is characterized in that the method The method comprises the following steps: First, preparing Al-Ni-Fe precursor strips First, the Al, Ni and Fe ingots are melted into Al (96-x) Ni4Fe x The intermediate alloy ingot, wherein 1≤x≤3, x is atomic percentage; subsequently, the intermediate alloy ingot is remelted at 1650~1800℃ by an induction coil of a vacuum tape caster, and after being kept in a molten state for 3~5 seconds, the melt is sprayed onto a copper wheel with a rotating speed of 30~40 m / s, and a spraying pressure difference of 0.8~1.0 MPa, to obtain a precursor strip. Second, preparing Al-Ni-Fe precursor powder The precursor strips are ball milled at a speed of 800-1000 r / min by using a mechanical ball milling method, and the ball milling time is 6-8 h, so as to obtain the precursor powder with a particle size of 1-3 μm; The volume ratio of the stainless steel milling balls to the precursor strips is (10-20):1, Third, preparing Ni3Fe / Ni / NiO composite materials The precursor powder prepared in the second step is immersed in a NaOH solution at 20-40℃ for 6-8 h to remove alloying, then washed with ultrapure water for 2-4 times, and then vacuum dried at 50-70℃ for 8-12 h, so as to obtain the intermetallic compound modified lithium ion battery negative electrode material, i.e. the Ni3Fe / Ni / NiO lithium ion battery negative electrode material. The concentration of the NaOH solution is 2.0-2.5 M.

2. The method for preparing the intermetallic compound modified lithium ion battery negative electrode material according to claim 1, characterized in that the thickness of the precursor strips is 20-30 μm, the width is 2.0-3.0 mm, and the length is 60-120 cm.

3. The method for preparing the intermetallic compound modified lithium ion battery negative electrode material according to claim 1, characterized in that the purity of the Al, Ni and Fe ingots is all 99.95 wt.%.

4. The method for preparing the intermetallic compound modified lithium ion battery negative electrode material according to claim 1, characterized in that the resistivity of the ultrapure water is 18.2 MΩ•cm.

5. The method for preparing the intermetallic compound modified lithium ion battery negative electrode material according to claim 1, characterized in that the diameter of the milling balls is 2-5 mm.

6. The method of claim 1, wherein the lithium-ion battery anode material has a porous nanowire network structure with eutectic microstructure characteristics, wherein the porous nanowire network structure has an average diameter of 35-55 nm, and the porous nanowire contains a secondary pore structure with an average pore diameter of 2-4 nm, and a specific surface area of 61-89 m 2 / g, and the Ni3Fe intermetallic compound is distributed in the Ni / NiO substrate.

7. Use of the intermetallic compound-modified lithium-ion battery anode material prepared by the preparation method according to claim 1, characterized in that, The method can be used for preparing the intermetallic compound modified lithium ion battery negative electrode material.

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