A ternary transition metal intermetallic compound and its applications

Abstract

This invention discloses a ternary transition metal intermetallic electronic compound and its applications. The molecular formula of the transition metal intermetallic electronic compound is A4BC; wherein transition metal A is Ti, Zr, or Hf; transition metal B is Mn, Fe, Co, or Ni; and transition metal C is Fe, Co, Ni, or Mo; the transition metal intermetallic electronic compound has a three-dimensional crystal structure. This invention provides an A4BC-type ternary transition metal intermetallic electronic compound with a spatial structure. Furthermore, the interstitial spaces of this electronic compound contain high-energy interstitial electrons that can migrate between adsorbed metal layers, stabilizing the positively charged metal ion layers together. Simultaneously, these high-energy interstitial positions of the electrons also facilitate the intercalation of metal ions, thereby enhancing the absorption of metal ions and increasing storage capacity.

Description

Technical Field

[0001] This invention belongs to the field of ternary intermetallic electronic compound materials technology, specifically relating to a ternary transition metal intermetallic electronic compound, its preparation method, and its application. Background Technology

[0002] With the rapid development of new energy vehicles, wearable devices, and other fields, the demand for battery performance is growing rapidly. Among them, the anode material, as one of the four key materials of the battery, has a significant impact on the battery's energy density, cycle performance, charge-discharge rate, and other performance characteristics.

[0003] Currently, graphite is the most widely used anode material for batteries; however, its theoretical specific capacity is limited to 372 mAh g⁻¹. -1 This limits further improvements in battery performance. To address this, researchers are constantly exploring new anode materials, such as lithium titanate, silicon-based, and tin-based materials, in an effort to overcome this limitation. Among them, silicon-based materials have attracted attention due to their ultra-high theoretical capacity. However, unfortunately, they are prone to volume expansion during charging and discharging, leading to a significant decrease in actual capacity and thus limiting their widespread application.

[0004] Electron compounds are a special class of compounds in which electrons act as anions. These anion electrons are periodically localized in the interstitial space and occupy high energy bands (crossing or approaching the Fermi level), making them easily excited and widely used in a range of catalytic fields such as ammonia synthesis, CO reduction, and selective catalytic hydrogenation. However, due to the active nature of these electrons, most electron compounds are unstable and easily oxidized and decomposed in air and water. Their battery applications remain largely theoretical, including those of transition metal intermetallic electron compounds, with few practical battery testing examples. Therefore, researching stable transition metal intermetallic electron compounds as battery anode materials not only holds promise for solving the current capacity and stability challenges of anode materials but also opens new avenues for their application in energy storage. This exploration has profound significance for the research of electron compounds themselves and will provide strong support for the continued advancement of battery technology. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a ternary transition metal intermetallic electronic compound and its applications. Specifically, due to the hybridization between interstitial electrons and metal atoms, intermetallic electronic compounds exhibit high stability. Therefore, based on first-principles calculations, we calculated the energy and electronic structures of a series of ternary intermetallic compounds composed of non-noble metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, and Hf, etc.) in the transition metals, obtaining seven theoretically thermodynamically stable and metastable A4BC-type ternary transition metal intermetallic electronic compounds. These compounds were then successfully synthesized and applied to battery performance testing. This ternary transition metal intermetallic electronic compound possesses… The spatial structure features high-energy gap electrons in the structural gaps of the electronic compound of the present invention, which can migrate between the adsorbed metal layers to stabilize the positively charged metal ion layers together. At the same time, the high-energy gap positions where the electrons are located are also conducive to the intercalation of metal ions, thereby enhancing the absorption of metal ions and increasing the storage capacity.

[0006] The present invention solves the above-mentioned technical problems through the following technical solutions.

[0007] The first objective of this invention is to provide a ternary intermetallic electronic compound with the molecular formula A4BC; wherein transition metal A is Ti, Zr, or Hf; transition metal B is Mn, Fe, Co, or Ni; and transition metal C is Fe, Co, Ni, or Mo; the intermetallic electronic compound has Type crystal structure.

[0008] Furthermore, the molecular formula of the transition metal intermetallic electronic compound is Ti4MnNi, Zr4FeMo, Zr4CoMo, Zr4NiMo, Hf4MnFe, Hf4MnCo, or Hf4FeCo.

[0009] Furthermore, the morphology of the transition metal intermetallic compound is any one or a combination of two or more of the following: powder, bulk, and thin film.

[0010] Furthermore, when the transition metal intermetallic compound is in the form of a powder, the particle size is 1 μm to 100 μm.

[0011] A second objective of this invention is to provide a method for preparing the aforementioned ternary transition metal intermetallic compound, comprising the following steps:

[0012] According to the stoichiometric ratio, transition metal powders A, B and C are weighed, mixed evenly, and then pressed into shape under 2MPa to 10MPa. The mixture is then smelted to obtain alloy A4BC.

[0013] Under an inert gas atmosphere, alloy A4BC was annealed at 200℃~1800℃ to obtain an intermetallic electron compound.

[0014] Furthermore, the annealing treatment time is 1h to 300h, the inert gas is argon, and the heating rate is 1℃ / min to 5℃ / min.

[0015] Furthermore, the melting method employs electric arc melting.

[0016] Furthermore, the particle size of the transition metal A powder, B powder and C powder is 50 mesh to 500 mesh.

[0017] A third objective of this invention is to provide the application of the aforementioned ternary transition metal intermetallic compounds in the preparation of battery anode materials.

[0018] Furthermore, the battery is a lithium battery, a sodium battery, or a potassium battery.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] (1) This invention provides an A4BC type ternary transition metal intermetallic electronic compound with... The spatial structure features high-energy gap electrons in the structural gaps of the electronic compound of the present invention, which can migrate between the adsorbed metal layers to stabilize the positively charged metal ion layers together. At the same time, the high-energy gap positions where the electrons are located are also conducive to the intercalation of metal ions, thereby enhancing the absorption of metal ions and increasing the storage capacity.

[0021] (2) The preparation method of the A4BC type ternary transition metal intermetallic electronic compound of the present invention is simple, the preparation cycle is short and it is easy to synthesize. The obtained material has better purity and crystallinity, good room temperature stability, and is conducive to battery performance testing. The A4BC type ternary transition metal intermetallic electronic compound can be used as a battery negative electrode material. The prepared battery has high reversible specific capacity and good cycle stability. Attached Figure Description

[0022] Figure 1 This is the thermodynamic ternary phase diagram of the Ti4MnNi ternary transition metal intermetallic electron compound of Example 1 of the present invention.

[0023] Figure 2 This is the thermodynamic ternary phase diagram of the Zr4FeMo ternary transition metal intermetallic electron compound in Example 2 of the present invention.

[0024] Figure 3 This is the thermodynamic ternary phase diagram of the Zr4CoMo ternary transition metal intermetallic electron compound in Example 3 of the present invention.

[0025] Figure 4This is the thermodynamic ternary phase diagram of the Zr4NiMo ternary transition metal intermetallic electron compound in Example 4 of the present invention.

[0026] Figure 5 The thermodynamic ternary phase diagram of the Hf4MnFe ternary transition metal intermetallic electron compound in Example 5 of the present invention.

[0027] Figure 6 The thermodynamic ternary phase diagram of the ternary transition metal intermetallic electron compound 6Hf4MnCo in Embodiment 6 of the present invention.

[0028] Figure 7 The thermodynamic ternary phase diagram of the Hf4FeCo ternary transition metal intermetallic electron compound in Example 7 of the present invention is shown.

[0029] Figure 8 This is the electronic structure diagram of the Ti4MnNi ternary transition metal intermetallic compound of Example 1 of the present invention, wherein, Figure 8 In the diagram, (a) represents the local charge function, and (b) represents the anion electron projection band.

[0030] Figure 9 This is the electronic structure diagram of the Zr4FeMo ternary transition metal intermetallic compound of Example 2 of the present invention, wherein, Figure 9 In the diagram, (a) represents the local charge function, and (b) represents the anion electron projection band.

[0031] Figure 10 This is the electronic structure diagram of the Zr4CoMo ternary transition metal intermetallic compound of Example 3 of the present invention, wherein, Figure 10 In the diagram, (a) represents the local charge function, and (b) represents the anion electron projection band.

[0032] Figure 11 This is the electronic structure diagram of the Zr4NiMo ternary transition metal intermetallic compound of Example 4 of the present invention, wherein, Figure 11 In the diagram, (a) represents the local charge function, and (b) represents the anion electron projection band.

[0033] Figure 12 This is the electronic structure diagram of the ternary transition metal intermetallic compound 5Hf4MnFe of the present invention, wherein... Figure 12 Figure (a) shows the local charge function, and (b) shows the anion electron projection band.

[0034] Figure 13 This is the electronic structure diagram of the ternary transition metal intermetallic compound 6Hf4MnCo according to Example 6 of the present invention, wherein, Figure 13 In the diagram, (a) represents the local charge function, and (b) represents the anion electron projection band.

[0035] Figure 14 This is the electronic structure diagram of the ternary transition metal intermetallic compound Hf4FeCo in Example 7 of the present invention, wherein... Figure 14 In the diagram, (a) represents the local charge function, and (b) represents the anion electron projection band.

[0036] Figure 15 This is the XRD pattern of the Ti4MnNi ternary transition metal intermetallic compound of Example 1 of the present invention.

[0037] Figure 16 This is the XRD pattern of the Zr4FeMo ternary transition metal intermetallic compound of Example 2 of the present invention.

[0038] Figure 17 This is the XRD pattern of the Zr4CoMo ternary transition metal intermetallic compound of Example 3 of the present invention.

[0039] Figure 18 This is the XRD pattern of the Zr4NiMo ternary transition metal intermetallic compound of Example 4 of the present invention.

[0040] Figure 19 This is the XRD pattern of the ternary transition metal intermetallic compound 5Hf4MnFe in Example 5 of the present invention.

[0041] Figure 20 The image shows the XRD pattern of the ternary transition metal intermetallic compound 6Hf4MnCo in Example 6 of this invention.

[0042] Figure 21 The image shows the XRD pattern of the Hf4FeCo ternary transition metal intermetallic compound of Example 7 of the present invention.

[0043] Figure 22 These are performance test graphs of the ternary transition metal intermetallic compounds used as lithium battery anode materials in Examples 1 and 7 of this invention. Figure 22 In the example, (a) is Ti4MnNi and (b) is Hf4FeCo.

[0044] Figure 23 The figures show the performance test results of the compounds in Example 1 and Comparative Example 1 of this invention as anode materials for sodium-ion batteries. Figure 23 In the example, (a) represents Ti4MnNi and (b) represents Ca2N. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] It should be noted that the technical terms used in this invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of this invention. Unless otherwise specified, all raw materials, reagents, instruments and equipment used in the following embodiments of this invention can be purchased from the market or prepared by existing methods.

[0047] On one hand, the present invention provides a ternary intermetallic electronic compound with the molecular formula A4BC; wherein transition metal A is Ti, Zr, or Hf; transition metal B is Mn, Fe, Co, or Ni; and transition metal C is Fe, Co, Ni, or Mo; wherein the transition metal...

[0048] —Inter-genus electron compounds have an F43m type crystal structure.

[0049] This invention provides a ternary transition metal intermetallic electronic compound, prepared using A, B, and C transition metals to form an A4BC type electronic compound. In this A4BC type compound, the interstitial electrons are localized in the octahedral interstitial spaces of the A element. The relatively low electronegativity (e.g., Ti, Zr, and Hf) facilitates electron localization in the interstitial spaces rather than being attracted to the atomic nucleus, thus readily forming an electronic compound.

[0050] —Electron compounds. The obtained electron compounds have the characteristics of an F43m spatial structure. The unit cell of this structure contains multiple high-energy interstitial electron sites, while most other electron compounds only have one or two interstitial electron sites. These electrons can migrate between the adsorbed metal layers, stabilizing the positively charged metal ion layers together. At the same time, the high-energy interstitial positions of these electrons also facilitate the intercalation of metal ions, thereby enhancing the absorption of metal ions and increasing the storage capacity.

[0051] In one specific embodiment, the molecular formula of the transition metal intermetallic electronic compound is Ti4MnNi, Zr4FeMo, Zr4CoMo, Zr4NiMo, Hf4MnFe, Hf4MnCo, or Hf4FeCo. The electronic structure of the transition metal intermetallic electronic compound is characterized by the presence of high-energy interstitial electrons within the interstitial space enclosed by the transition metals; this charge localization characteristic can be determined by first-principles calculations.

[0052] Depend on Figures 1 to 7 It can be seen that Zr4FeMo, Zr4CoMo, Hf4MnFe, Hf4MnCo, and Hf4FeCo, calculated using first-principles methods, all possess thermodynamic stability, indicating that these compounds can theoretically be synthesized experimentally. Although the Et of Ti4MnNi and Zr4NiMo... hull The values ​​are greater than 0, at 0.012 eV / atom and 0.01 eV / atom respectively, classifying them as metastable structures, but they still possess the potential for experimental synthesis. Figures 8 to 14 First-principles calculations show that Ti4MnNi, Zr4FeMo, Zr4CoMo, Zr4NiMo, Hf4MnFe, Hf4MnCo, and Hf4FeCo all exhibit the significant characteristics of electronic compounds. The charge localization function plot (Isosurfaces = 0.7) reveals multiple electronic localizations within the crystal structure, denoted by V1, V2, and V3, with the projected energy bands of these localized electrons located near the Fermi level.

[0053] In one specific embodiment, the morphology of the transition metal intermetallic compound is any one or a combination of two or more of the following: powder, bulk, and thin film. When the morphology of the transition metal intermetallic compound is powder, the particle size is 1 μm to 100 μm.

[0054] On the other hand, the present invention provides a method for preparing the above-mentioned ternary transition metal intermetallic electronic compound, comprising the following steps:

[0055] S1. Weigh transition metal powders A, B, and C according to stoichiometric ratio, mix them evenly, and press them into shape under 2MPa-10MPa. Then, melt them to obtain alloy A4BC. It should be noted that this invention does not limit the specific process of melting A, B, and C into alloy A4BC, as long as the three elements A, B, and C are fully and evenly mixed to form a homogeneous A4BC alloy. This invention preferably uses an electric arc melting method, and the specific process is as follows: Weigh and evenly mix the metal powders, press them into small pieces using a tablet press at 2MPa-10MPa, place them in a copper crucible in a melting furnace, and then perform electric arc melting in an argon atmosphere. During electric arc melting, adjust the current to keep the sample in a molten state for 3-15 seconds; flip the metal ingot and repeat the melting process 1-10 times. This invention does not limit the specific magnitude of the current; it can be adjusted according to the actual selected materials A, B, and C, as long as the sample is kept in a molten state.

[0056] S2. The A4BC alloy after arc melting is pulverized in a glove box, and then the alloy powder is wrapped in tantalum foil and sealed in a quartz tube. Under an inert gas atmosphere, the alloy A4BC is annealed at 200℃~1800℃ to obtain an intermetallic electron compound. It should be noted that this invention does not limit the specific annealing temperature and time, which can be adjusted according to the actual selection of materials A, B, and C, to achieve the goal of forming a compound from the three elements and ensuring the sample is homogeneous and has good purity. Optionally, the annealing is performed at 200℃~1800℃ for 1h~300h, with a heating rate of 1℃ / min~5℃ / min. Preferably, the annealing temperature is 700℃~1400℃, and the annealing time is 200h~300h.

[0057] In one specific embodiment, the particle size of the transition metal A powder, B powder and C powder is 50 mesh to 500 mesh.

[0058] A third objective of this invention is to provide the application of the aforementioned A4BC type ternary transition metal intermetallic compound in the preparation of battery anode materials. The battery is a lithium battery, sodium battery, or potassium battery. The A4BC type ternary transition metal intermetallic compound is stable at room temperature, which facilitates battery performance testing. When used as a battery anode material, the prepared battery exhibits high reversible specific capacity and good cycle stability.

[0059] The following specific examples will provide further explanation.

[0060] Example 1

[0061] A ternary transition metal intermetallic compound material of type A4BC with the molecular formula Ti4MnNi.

[0062] The preparation method of the above-mentioned A4BC type ternary transition metal intermetallic compound material includes the following steps:

[0063] S1. Weigh out Ti, Mn, and Ni metal powders according to the stoichiometric ratio of Ti:Mn:Ni = 4:1:1 and mix them. The particle size of the Ti, Mn, and Ni metal powders is 100 mesh. Then, press the mixed metal powder into small pieces using a tablet press at 2MPa to 10MPa and place them into a micro metal melting furnace. Before melting, flush the melting furnace cavity with argon gas and evacuate it to a vacuum value of 10 using a molecular pump. -5Pa, repeated 3 times, the last time Ar gas was filled at -0.2 MPa. After the operation was completed, Ti particles were used for deoxygenation. Then, the pressed metal block was placed in the copper crucible of the melting furnace and electric arc melting was carried out in an argon atmosphere. During the electric arc melting, the current was adjusted to keep the sample in the molten state for 7 seconds, and then it was flipped and the melting was continued to be kept in the molten state for 7 seconds. The melting was repeated 6 times to ensure that the alloy was melted uniformly. After the sample cooled, it was taken out to obtain the alloy Ti4MnNi.

[0064] S2. The cooled Ti4MnNi alloy sample was ground in a mortar to obtain a Ti4MnNi alloy powder sample. The obtained Ti4MnNi alloy powder was wrapped in tantalum foil and sealed in a quartz tube under an argon atmosphere in a glove box. The quartz tube was heated to 900℃ at a heating rate of 3℃ / min and held for 160h. Finally, the sample was taken out of the quartz tube in the glove box and ground to obtain the final Ti4MnNi electronic compound.

[0065] Example 2

[0066] A ternary transition metal intermetallic compound material of type A4BC with the molecular formula Zr4FeMo.

[0067] The preparation method of the above-mentioned A4BC type ternary transition metal intermetallic compound material includes the following steps:

[0068] S1. Weigh out Zr, Fe, and Mo metal powders according to the stoichiometric ratio of 4:1:1 and mix them. The particle size of the Zr, Fe, and Mo metal powders is 100 mesh. Then, press the mixed metal powder into small pieces using a tablet press at 2MPa to 10MPa and place them into a micro metal smelting furnace. Before smelting, flush the furnace chamber with argon gas and evacuate it to a vacuum value of 10 using a molecular pump. -5 Pa, repeated 3 times, the last time Ar gas was filled at -0.2 MPa. After the operation was completed, Ti particles were used for deoxygenation. Then, the pressed metal block was placed in the copper crucible of the melting furnace and electric arc melting was carried out in an argon atmosphere. During the electric arc melting, the current was adjusted to keep the sample in the molten state for 7 seconds, and then it was flipped and the melting was continued to be kept in the molten state for 7 seconds. The melting was repeated 6 times to ensure that the alloy was melted uniformly. After the sample cooled, it was taken out to obtain the alloy Zr4FeMo.

[0069] S2. The cooled Zr4FeMo alloy sample is ground in a mortar to obtain Zr4FeMo alloy powder sample; the obtained Zr4FeMo alloy powder is wrapped and sealed in a quartz tube with tantalum foil under an argon atmosphere in a glove box; the quartz tube is heated to 1000℃ at a heating rate of 3℃ / min and held at that temperature for 160h; finally, the sample is taken out of the quartz tube in the glove box and ground to obtain the final Zr4FeMo electronic compound.

[0070] Example 3

[0071] A ternary transition metal intermetallic compound material of type A4BC with the molecular formula Zr4CoMo.

[0072] The preparation method of the above-mentioned A4BC type ternary transition metal intermetallic compound material includes the following steps:

[0073] S1. Weigh out Zr, Co, and Mo metal powders in a stoichiometric ratio of 4:1:1 and mix them. The particle size of the Zr, Co, and Mo metal powders is 100 mesh. Then, press the mixed metal powder into small pieces using a tablet press at 2MPa to 10MPa and place them into a micro metal smelting furnace. Before smelting, flush the furnace chamber with argon gas and evacuate it to a vacuum value of 10 using a molecular pump. -5 Pa, repeated 3 times, the last time filled with Ar gas at -0.2 MPa. After the operation was completed, Ti particles were used for deoxygenation. Then, the pressed metal block was placed in the copper crucible of the melting furnace and electric arc melting was carried out in an argon atmosphere. During the electric arc melting, the current was adjusted to keep the sample in the molten state for 7 seconds, and then flipped to continue melting and keep the molten state for 7 seconds. The melting was repeated 6 times to ensure that the alloy was melted uniformly. After the sample cooled, it was taken out to obtain the alloy Zr4CoMo.

[0074] S2. The cooled Zr4CoMo alloy sample was ground in a mortar to obtain Zr4CoMo alloy powder. The obtained Zr4CoMo alloy powder was wrapped in tantalum foil and sealed in a quartz tube under an argon atmosphere in a glove box. The quartz tube was heated to 1000℃ at a heating rate of 3℃ / min and held at that temperature for 160h. Finally, the sample was removed from the quartz tube in the glove box and ground to obtain the final Zr4CoMo electronic compound.

[0075] Example 4

[0076] A ternary transition metal intermetallic compound material of type A4BC with the molecular formula Zr4NiMo.

[0077] The preparation method of the above-mentioned A4BC type ternary transition metal intermetallic compound material includes the following steps:

[0078] S1. Weigh out Zr, Ni, and Mo metal powders according to the stoichiometric ratio of 4:1:1 and mix them. The particle size of the Zr, Ni, and Mo metal powders is 100 mesh. Then, press the mixed metal powder into small pieces using a tablet press at 2MPa to 10MPa and place them into a micro metal smelting furnace. Before smelting, flush the furnace chamber with argon gas and evacuate it to a vacuum value of 10 using a molecular pump. -5Pa, repeated 3 times, the last time Ar gas was filled at -0.2 MPa. After the operation was completed, Ti particles were used for deoxygenation. Then, the pressed metal block was placed in the copper crucible of the melting furnace and electric arc melting was carried out in an argon atmosphere. During the electric arc melting, the current was adjusted to keep the sample in the molten state for 7 seconds, and then it was flipped and the melting was continued to be kept in the molten state for 7 seconds. The melting was repeated 6 times to ensure that the alloy was melted uniformly. After the sample cooled, it was taken out to obtain the alloy Zr4NiMo.

[0079] S2. The cooled Zr4NiMo alloy sample was ground in a mortar to obtain Zr4NiMo alloy powder. The obtained Zr4NiMo alloy powder was wrapped in tantalum foil and sealed in a quartz tube under an argon atmosphere in a glove box. The quartz tube was kept at 1000℃ for 160h. Finally, the sample was taken out of the quartz tube in the glove box and ground to obtain the final Zr4NiMo electronic compound.

[0080] Example 5

[0081] A ternary transition metal intermetallic compound material of type A4BC with the molecular formula Hf4MnFe.

[0082] The preparation method of the above-mentioned A4BC type ternary transition metal intermetallic compound material includes the following steps:

[0083] S1. Weigh out Hf, Mn, and Fe metal powders according to the stoichiometric ratio of 4:1:1 and mix them. The particle size of the Hf, Mn, and Fe metal powders is 100 mesh. Then, press the mixed metal powder into small pieces using a tablet press at 2MPa to 10MPa and place them into a micro metal smelting furnace. Before smelting, flush the furnace cavity with argon gas and evacuate it to a vacuum value of 10 using a molecular pump. -5 Pa, repeated 3 times, the last time Ar gas was filled at -0.2 MPa. After the operation was completed, Ti particles were used for deoxygenation. Then, the pressed metal block was placed in the copper crucible of the melting furnace and electric arc melting was carried out in an argon atmosphere. During the electric arc melting, the current was adjusted to keep the sample in the molten state for 7 seconds, and then it was flipped and the melting was continued to be kept in the molten state for 7 seconds. The melting was repeated 6 times to ensure that the alloy was melted uniformly. After the sample cooled, it was taken out to obtain the alloy Hf4MnFe.

[0084] S2. The cooled Hf4MnFe alloy sample is ground in a mortar to obtain Hf4MnFe alloy powder sample; the obtained Hf4MnFe alloy powder is wrapped and sealed in a quartz tube with tantalum foil under an argon atmosphere in a glove box; the quartz tube is heated to 1000℃ at a heating rate of 3℃ / min and held for 160h; finally, the sample is taken out of the quartz tube in the glove box and ground to obtain the final Hf4MnFe electronic compound.

[0085] Example 6

[0086] A ternary transition metal intermetallic compound material of type A4BC with the molecular formula Hf4MnCo.

[0087] The preparation method of the above-mentioned A4BC type ternary transition metal intermetallic compound material includes the following steps:

[0088] S1. Weigh out Ti, Mn, and Ni metal powders according to the stoichiometric ratio of Hf:Mn:Co = 4:1:1 and mix them. The particle size of the Ti, Mn, and Ni metal powders is 100 mesh. Then, press the mixed metal powder into small pieces using a tablet press at 2MPa~10MPa and place them into a micro metal melting furnace. Before melting, flush the melting furnace cavity with argon gas and evacuate it to a vacuum value of 10 using a molecular pump. -5 Pa, repeated 3 times, the last time Ar gas was filled at -0.2 MPa. After the operation was completed, Ti particles were used for deoxygenation. Then, the pressed metal block was placed in the copper crucible of the melting furnace and electric arc melting was carried out in an argon atmosphere. During the electric arc melting, the current was adjusted to keep the sample in the molten state for 7 seconds, and then it was flipped and the melting was continued to be kept in the molten state for 7 seconds. The melting was repeated 6 times to ensure that the alloy was melted uniformly. After the sample cooled, it was taken out to obtain the alloy Hf4MnCo.

[0089] S2. The cooled Hf4MnCo alloy sample is ground in a mortar to obtain Hf4MnCo alloy powder sample; the obtained Hf4MnCo alloy powder is wrapped and sealed in a quartz tube with tantalum foil under an argon atmosphere in a glove box; the quartz tube is heated to 1000℃ at a heating rate of 3℃ / min and held for 160h; finally, the sample is taken out of the quartz tube in the glove box and ground to obtain the final Hf4MnCo electronic compound.

[0090] Example 7

[0091] A ternary transition metal intermetallic compound material of type A4BC with the molecular formula Hf4FeCo.

[0092] The preparation method of the above-mentioned A4BC type ternary transition metal intermetallic compound material includes the following steps:

[0093] S1. Weigh out Hf, Fe, and Co metal powders according to the stoichiometric ratio of 4:1:1 and mix them. The particle size of the Hf, Fe, and Co metal powders is 100 mesh. Then, press the mixed metal powder into small pieces using a tablet press at 2MPa to 10MPa and place them into a micro metal melting furnace. Before melting, flush the melting furnace cavity with argon gas and evacuate it to a vacuum value of 10 using a molecular pump. -5Pa, repeated 3 times, the last time Ar gas was filled at -0.2 MPa. After the operation was completed, Ti particles were used for deoxygenation. Then, the pressed metal block was placed in the copper crucible of the melting furnace and electric arc melting was carried out in an argon atmosphere. During the electric arc melting, the current was adjusted to keep the sample in the molten state for 7 seconds, and then it was flipped and the melting was continued to be kept in the molten state for 7 seconds. The melting was repeated 6 times to ensure that the alloy was melted uniformly. After the sample cooled, it was taken out to obtain alloy Hf4FeCo.

[0094] S2. The cooled Hf4FeCo alloy sample is ground in a mortar to obtain Hf4FeCo alloy powder sample; the obtained Hf4FeCo alloy powder is wrapped and sealed in a quartz tube with tantalum foil under an argon atmosphere in a glove box; the quartz tube is heated to 900℃ at a heating rate of 3℃ / min and held for 160h; finally, the sample is taken out of the quartz tube in the glove box and ground to obtain the final Hf4FeCo electronic compound.

[0095] Comparative Example 1

[0096] Electron-containing compound Ca2N.

[0097] The structures of the ternary transition metal intermetallic compounds prepared in Examples 1-7 were tested, and the results are as follows.

[0098] Figure 15 The image shows the XRD pattern of the Ti4MnNi ternary transition metal intermetallic compound of Example 1 of this invention. Figure 16 The XRD pattern of the Zr4FeMo ternary transition metal intermetallic compound of Example 2 of this invention; Figure 17 The XRD pattern of the Zr4CoMo ternary transition metal intermetallic compound of Example 3 of the present invention is shown below. Figure 18 The XRD pattern of Zr4NiMo, a ternary transition metal intermetallic compound, in Example 4 of this invention; Figure 19 The XRD pattern of the ternary transition metal intermetallic compound 5Hf4MnFe in Example 5 of the present invention; Figure 20 The XRD pattern of the ternary transition metal intermetallic compound 6Hf4MnCo in Example 6 of the present invention; Figure 21 This is the XRD pattern of the ternary intermetallic transition metal compound Hf4FeCo in Example 7 of the present invention. Figure 15-21 It can be seen that the A4BC type ternary transition metal intermetallic compound materials prepared in Examples 1-7 of this invention all have good purity and good crystallinity.

[0099] The ternary transition metal intermetallic compounds prepared in Examples 1 and 7 were used as negative electrode materials for lithium batteries, and battery performance was tested. The testing method was as follows: First, 70 wt% of active material, 20 wt% of carbon black, and 10 wt% of polyvinylidene fluoride (PVDF) were uniformly ground in 1-methyl-2-pyridone (NMP). Then, the resulting slurry was coated onto copper foil and vacuum dried at 60°C for 24 hours. After drying, a circular electrode with a diameter of 12 mm was obtained using a slicing machine. Then, a coin cell battery was assembled in an argon-filled glove box. The counter electrode, electrolyte, and separator used were lithium foil, 1M lithium hexafluorophosphate (LiPF6), and a polypropylene microporous membrane, respectively. The assembled coin cell battery was tested using a Neware battery testing system in Shenzhen, China. The test results are as follows. Figure 22 As shown.

[0100] Figure 22 These are performance test diagrams of the A4BC type ternary transition metal intermetallic compound used as a negative electrode material in Examples 1 and 7 of this invention for lithium batteries. Figure 22 In the example, (a) is Ti4MnNi and (b) is Hf4FeCo. (The sentence is incomplete and requires further context.) Figure 22 It can be seen that both Ti4MnNi and Hf4FeCo anode materials have high charge-discharge specific capacity and good cycle stability. (At 0.1 A·g) -1 At a current density, the reversible specific capacity of Ti4MnNi stabilizes at 181 mAh·g after 500 cycles. -1 The reversible specific capacity of Hf4FeCo remained stable at 282 mAh·g after 280 cycles. -1 This demonstrates that the A4BC type ternary transition metal intermetallic compound material prepared by this invention can be used as a negative electrode material for lithium batteries.

[0101] The ternary transition metal intermetallic compound prepared in Example 1 was used as the negative electrode material for a sodium battery, and battery performance was tested. The testing method was as follows: First, 70 wt% of active material, 20 wt% of carbon black, and 10 wt% of polyvinylidene fluoride (PVDF) were uniformly ground in 1-methyl-2-pyridone (NMP). Then, the resulting slurry was coated onto copper foil and vacuum dried at 60°C for 24 hours. After drying, a circular electrode with a diameter of 12 mm was obtained using a slicing machine. Then, a coin cell battery was assembled in an argon-filled glove box. The counter electrode, electrolyte, and separator used were sodium foil, 1M sodium perchlorate (NaClO4), and a glass fiber membrane, respectively. The assembled coin cell battery was tested using a Neware battery testing system in Shenzhen, China.

[0102] Comparative Example 1: Sodium-ion battery test method for the electronic compound Ca2N (refer to ACS Appl. Mater. Interfaces, 2017, 9, 8, 6666-6669): First, nickel foam (100mm × 50mm × 1mm) was washed three times with deionized water and ethanol respectively, and then dried overnight in a vacuum oven at 80°C. Next, one side of the nickel foam (side A) was scraped to reduce the pore size of the surface layer. Then, a slurry mixed with Super P (Timcal) and polyvinylidene fluoride (PVDF) binder at a weight ratio of 2:1 was coated onto side A and dried overnight in a vacuum oven at 80°C. Because the pores on side A were blocked, Ca2N powder could not pass through the nickel foam. A thin sheet with a pore diameter of 11mm was punched from the coated nickel foam and used as a current collector, with a dry composite mass loading of 5.5 mg·cm⁻¹. -2 Then, Ca2N powder was dispersed on the other side (B side) of the current collector without coating the composite slurry (Super P and PVDF). After calendering at 8 MPa for 2 min, a Ca2N mass loading of approximately 1.7 mg·cm⁻¹ was prepared. -2 Compression-molded electrodes are used for sodium battery performance testing.

[0103] Figure 23 The figures show the performance test results of the compounds in Example 1 and Comparative Example 1 of this invention as anode materials for sodium-ion batteries. Figure 23 In the example, (a) is Ti4MnNi and (b) is Ca2N. (The rest of the text appears to be incomplete and requires further context.) Figure 23 It can be seen that: Example 1, Ti4MnNi, exhibits good stability when used as a negative electrode material for sodium-ion batteries, at 0.1 A g. -1 At a current density, the reversible specific capacity of Ti4MnNi remains stable at 80 mAh·g over 330 cycles. -1 The change in pH does not decrease. However, Ca2N at 0.05 A·g -1 At a current density of 300 mAh·g -1 It showed a reversible specific capacity, but only maintained it for 35 cycles, after which the reversible specific capacity dropped to 180 mAh·g after 50 cycles. -1 This demonstrates that the A4BC type ternary transition metal intermetallic compound material prepared by this invention can be used as a stable anode material for sodium batteries.

[0104] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described here to avoid redundancy. Although preferred embodiments of the invention have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this invention.

[0105] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A ternary transition metal intermetallic compound, characterized in that, The molecular formula of the transition metal intermetallic compound is: A 4 B C; the transition metal intermetallic compound has F 3 m The transition metal intermetallic compound has a crystal structure and the molecular formula is Ti4MnNi, Zr4FeMo, Zr4CoMo, Zr4NiMo, Hf4MnFe, Hf4MnCo, or Hf4FeCo.

2. The ternary transition metal intermetallic compound according to claim 1, characterized in that, The morphology of the transition metal intermetallic compound is any one or a combination of two or more of the following: powder, bulk, and thin film.

3. The ternary transition metal intermetallic compound according to claim 1, characterized in that, When the transition metal intermetallic electronic compound is in the form of a powder, the particle size is 1 µm to 100 µm.

4. A method for preparing a ternary transition metal intermetallic compound according to any one of claims 1-3, characterized in that, Includes the following steps: Transition metal powders A, B, and C were weighed according to stoichiometric ratios, mixed evenly, pressed into shape, and then smelted to obtain an alloy. A 4 B C; In an inert gas atmosphere, the alloy A 4 B Annealing C at 200℃~1800℃ yields intermetallic electron compounds.

5. The method for preparing ternary transition metal intermetallic electronic compounds according to claim 4, characterized in that, The annealing process takes 1 to 300 hours, uses argon as the inert gas, and has a heating rate of 1°C / min to 5°C / min.

6. The method for preparing ternary transition metal intermetallic electronic compounds according to claim 4, characterized in that, The smelting method is electric arc smelting.

7. The method for preparing ternary transition metal intermetallic electronic compounds according to claim 4, characterized in that, The particle size of the transition metal A powder, B powder and C powder is 50 mesh to 500 mesh.

8. The use of a ternary transition metal intermetallic compound according to any one of claims 1-3 in the preparation of battery anode materials.

9. The application according to claim 8, characterized in that, The battery is a lithium battery, sodium battery, or potassium battery.

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