Powder material, preparation method thereof and electrode material

Abstract

The invention discloses a powder material, a preparation method thereof and an electrode material. The powder material comprises a raw material and a refiner, the refiner comprises at least one of silicon, aluminum oxide, cerium oxide, titanium dioxide, lanthanum oxide, silicon dioxide, zirconium dioxide, nickel oxide, iron oxide, silver, aluminum and iron; the raw material comprises silicon; or a combination of silicon and aluminum; the addition amount of the refiner is 0.01%-2% of the mass of the raw materials. The novel refiners are adopted, the grain size of the powder material can be effectively refined, and the refiners are easy to obtain.

Description

Technical Field

[0001] The present application relates to the technical field of inorganic materials, and in particular to powder materials and preparation methods thereof, and electrode materials. Background Art

[0002] Powder metallurgy has unique chemical composition and mechanical and physical properties, which cannot be obtained by traditional melting and casting methods. Due to the advantages of powder metallurgy technology, powder metallurgy technology is widely used in transportation, machinery, electronics, aerospace, weapons, biology, new energy, information and nuclear industries. It has become the key to solving new material problems and plays a vital role in the development of new materials. In order to meet the needs of various fields, the requirements for powder materials are getting higher and higher, especially the standards of particle size and morphology have received great attention.

[0003] Grain size has an important influence on the performance of powder materials. Taking alloy powder as an example, the smaller the grain size at room temperature, the higher the strength and hardness of the metal, and the better the plasticity and toughness. Currently, the commonly used methods for grain refinement are: (1) increasing the degree of supercooling; (2) refinement treatment; (3) vibration treatment. Among them, the refinement treatment method mainly involves adding a certain chemical element or compound (modifier) ​​to the liquid metal. Commonly used refiners include titanium block refiners, salt refiners, and intermediate alloy refiners. These refiners are difficult to synthesize. In addition, refiners containing phosphorus are more corrosive to equipment. Therefore, the development of suitable refiners is of great significance for the preparation of high-performance alloy powders. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems in the related art to a certain extent. To this end, one purpose of the present application is to provide a powder material and a preparation method thereof, and an electrode material. The powder material of the present application adopts a new refiner, which can effectively refine the grain size of the powder material, and these refiners are easy to obtain.

[0005] The first aspect of the present application provides a powder material. According to an embodiment of the present application, the powder material includes: a raw material and a refiner; The refiner includes at least one of silicon, aluminum oxide, cerium oxide, titanium dioxide, lanthanum oxide, silicon dioxide, zirconium dioxide, nickel oxide, iron oxide, silver, aluminum and iron; The raw materials include: silicon; or a combination of silicon and aluminum; The amount of refiner added is 0.01%~2% of the mass of the raw material.

[0006] The raw materials of the powder material proposed in this application are silicon-containing materials, which are specifically divided into two types: one is silicon; the other is a combination of silicon and aluminum. When the above raw materials are used to prepare the powder material, the silicon in the raw material is first precipitated and becomes solid during the process of heating to prepare the melt. The addition of a refiner mainly acts on the silicon, which can serve as a nucleation point for the precipitated silicon, promote the refinement of silicon grains, and obtain a nano-level ultrafine powder material.

[0007] The refiner provided in this application has the characteristics of high temperature resistance and chemical inertness. It will not melt in the high temperature environment of preparing powder materials, providing stable crystal seeds, and chemical inertness, ensuring that chemical reactions will not occur in the preparation process and finished materials, affecting the performance of the powder materials. The refiner provided in this embodiment is easy to process into nano-scale ultrafine powders, such as reaching less than 50 nm, which is conducive to effectively realizing the refinement of powder materials.

[0008] In addition, the refiner provided in the present application is relatively easy to obtain and has almost no corrosive effect on equipment.

[0009] In some embodiments of the present application, at least one of the following is satisfied: (i) the refiner comprises at least one of silicon and silicon dioxide; (ii) Raw materials include: a combination of silicon and aluminum.

[0010] In some embodiments of the present application, the amount of the refiner added is 0.5% to 1% of the mass of the raw material; and / or the average particle size of the refiner is 5 nm to 20 nm.

[0011] In some embodiments of the present application, the raw material is a combination of silicon and aluminum, and the mass percentage of silicon is 10% to 50%.

[0012] The second aspect of the present application provides a method for preparing a powder material, comprising the steps of: The raw material is subjected to heat treatment to obtain a molten body; the raw material comprises: silicon; or a combination of silicon and aluminum; The melt is mixed with a refiner to obtain a mixed material; the refiner comprises at least one of silicon, aluminum oxide, cerium oxide, titanium dioxide, lanthanum oxide, silicon dioxide, zirconium dioxide, nickel oxide, iron oxide, silver, aluminum and iron; and the amount of the refiner added is 0.01% to 2% of the mass of the raw material; The mixed material is cooled to obtain a powder material.

[0013] The method for preparing the powder material provided in the present application adopts a new refining agent, which is used in combination with the raw material of the silicon-containing material, and has a good refining effect on the silicon-containing material.

[0014] The present application provides a method for preparing a powder material, wherein the raw material used is a silicon-containing material, which is specifically divided into two types: one is silicon; the other is a combination of silicon and aluminum. When the above raw materials are used to prepare the powder material, in the process of heating and preparing the melt, the silicon in the raw material is first precipitated and becomes solid. By adding a refiner that mainly acts on the silicon, it can serve as a nucleation point for the precipitated silicon, promote the refinement of silicon grains, and obtain a nano-level ultrafine powder material.

[0015] The refiner used in the preparation method provided in this application has the characteristics of high temperature resistance and chemical inertness. It will not melt in the high temperature environment of preparing powder materials, providing stable crystal seeds, and chemical inertness, ensuring that chemical reactions will not occur in the preparation process and finished materials, affecting the performance of the powder materials. The refiner provided in this embodiment is easy to process into nano-scale ultrafine powders, such as reaching less than 50 nm, which is conducive to effectively realizing the refinement of powder materials.

[0016] In addition, the refiner used in the preparation method provided in the present application is relatively easy to obtain and has basically no corrosive effect on the equipment.

[0017] In some embodiments of the present application, at least one of the following is satisfied: (i) the refiner comprises at least one of silicon and silicon dioxide; (ii) Raw materials include: a combination of silicon and aluminum.

[0018] In some embodiments of the present application, the amount of the refiner added is 0.5% to 1% of the mass of the raw material; and / or the average particle size of the refiner is 5 nm to 20 nm.

[0019] In some embodiments of the present application, the raw material is a combination of silicon and aluminum, and the mass percentage of silicon is 10% to 50%.

[0020] In some embodiments of the present application, D50 of the powder material is 20 μm to 40 μm, and / or the grain size of the powder material is less than 70 nm.

[0021] In some embodiments of the present application, the preparation method satisfies at least one of the following: (i) in the step of heat treating the raw material, the control parameters include: a temperature of 680°C to 1200°C; (ii) in the step of heat treating the raw material, the heat treatment temperature is within 150° C. higher than the melting temperature of the raw material; (iii) In the step of mixing the melt with the refiner, the temperature is maintained at the heat treatment temperature after mixing for a period of 10 minutes to 5 hours.

[0022] The third aspect of the present application proposes an electrode material, wherein the raw material for preparing the electrode material includes the above-mentioned powder material, or includes the powder material prepared by the above-mentioned preparation method.

[0023] The electrode material provided in the present application is prepared from raw materials including the above-mentioned powder material, or including the powder material prepared by the above-mentioned preparation method, and the powder material has a smaller grain size and a smaller powder particle size, which is conducive to obtaining an electrode with good electrical properties. Specifically, for example, a smaller grain size can increase the specific surface area of ​​the material, thereby increasing the contact area with the electrolyte, which helps to improve the charge and discharge efficiency and rate capability of the battery. In addition, fine grains can reduce volume expansion and contraction during the charge and discharge process, thereby improving the structural stability and cycle life of the negative electrode material.

[0024] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 The TEM image of the powder material obtained in Example 1 of the present application is shown, with a scale of 20 nm.

[0026] Figure 2 The TEM image of the powder material obtained in Example 1 of the present application is shown, with a scale of 50 μm. DETAILED DESCRIPTION

[0027] The embodiments of the present application are described in detail below. The embodiments described below are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0028] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Further, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0029] The endpoints and any values ​​of the ranges disclosed in this application are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in this application.

[0030] In the present application, the terms "comprise" or "include" are open expressions, that is, including the contents specified in the present application but not excluding other contents.

[0031] Grain size has an important influence on the performance of powder materials. Taking alloy powder as an example, the smaller the grain size at room temperature, the higher the strength and hardness of the metal, and the better the plasticity and toughness. Currently, the commonly used methods for refining grains are: (1) increasing the degree of supercooling; (2) refining treatment; (3) vibration treatment. Among them, the method of refining treatment mainly involves adding a certain chemical element or compound (modifier) ​​to the liquid metal. Commonly used refiners include titanium block refiners, salt refiners, and intermediate alloy refiners. These refiners are difficult to synthesize. In addition, refiners containing phosphorus are more corrosive to equipment. Therefore, the development of suitable refiners is of great significance to the preparation of high-performance alloy powders. For this reason, the embodiment of this application uses a new refiner for silicon-containing powder, which can replace the original refiner, as shown below.

[0032] In a first aspect, an embodiment of the present application provides a powder material, including a raw material and a refiner; The refiner includes at least one of silicon, aluminum oxide, cerium oxide, titanium dioxide, lanthanum oxide, silicon dioxide, zirconium dioxide, nickel oxide, iron oxide, silver, aluminum and iron; The raw materials include: silicon; or a combination of silicon and aluminum; The amount of refiner added is 0.01%~2% of the mass of the raw material.

[0033] The raw materials of the powder material proposed in the embodiment of the present application are silicon-containing materials, which are specifically divided into two types: one is silicon; the other is a combination of silicon and aluminum. When the above raw materials are used to prepare the powder material, the silicon in the raw material is first precipitated and becomes solid during the process of heating to prepare the melt. The addition of the refiner mainly acts on the silicon, which can serve as a nucleation point for the precipitated silicon, promote the refinement of silicon grains, and obtain a nano-level ultrafine powder material.

[0034] The refiner provided in the embodiment of the present application has the characteristics of high temperature resistance and chemical inertness. It will not melt in the high temperature environment of preparing powder materials, providing stable crystal seeds, and chemical inertness ensures that chemical reactions will not occur in the preparation process and finished materials, affecting the performance of the powder materials. The refiner provided in the embodiment of the present application is easy to process into nano-scale ultrafine powders, such as reaching less than 50 nm, which is conducive to effectively realizing the refinement of powder materials.

[0035] In the embodiment of the present application, the amount of refiner added meets the above conditions, which is conducive to promoting the refinement of the powder material and ensuring low production costs. If too little refiner is added, the number of nucleation points is small, and the grain size of the formed powder material will become larger; if too much refiner is added, other refiners other than silicon will cause the impurity content or oxygen content in the material to increase, and a large amount of nano-silicon used in a high temperature environment is prone to safety problems and excessive use costs. In a specific example, the amount of refiner added is 0.01%, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, etc. of the mass of the raw material.

[0036] In addition, the refiner provided in the embodiments of the present application is relatively easy to obtain and has almost no corrosive effect on the equipment.

[0037] In some embodiments of the present application, the refiner includes at least one of silicon, silicon dioxide, aluminum oxide and zirconium oxide.

[0038] In the embodiments of the present application, at least one of silicon, silicon dioxide, aluminum oxide and zirconium oxide is selected as a refiner for the silicon-containing powder material, which is beneficial to promote the grain refinement of the powder material and obtain a powder material with a small grain size and a smaller powder particle size.

[0039] In some embodiments of the present application, in the combination of silicon and aluminum, the mass percentage of silicon is 10% to 50% of the total mass of the combination.

[0040] In the embodiment of the present application, the silicon content meets the above conditions, and the above raw materials are used to prepare the powder material. When the raw materials are heated to prepare the melt, it is beneficial to ensure that the melt maintains a low viscosity state, so that when cooling, it maintains a good heat dissipation state and avoids excessive grain size. In specific examples, the mass percentage of silicon is 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, etc. of the total mass of the combination.

[0041] In some embodiments of the present application, in a combination of silicon and at least one of aluminum, magnesium, iron, calcium, cobalt, nickel, copper, zinc, tin and phosphorus, the mass percentage of silicon is 20% to 30% of the total mass of the combination.

[0042] In the embodiment of the present application, the silicon content meets the above conditions, which is conducive to forming a powder material with smaller grains. In specific examples, the mass percentage of silicon is 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, etc. of the total mass of the combination.

[0043] In some embodiments of the present application, D50 of the powder material is 20 μm to 40 μm, and / or the grain size of the powder material is less than 70 nm.

[0044] The embodiment of the present application adopts a refiner and controls the amount of the refiner, which can serve as a nucleation point for precipitated silicon, promote the refinement of silicon grains, and obtain a nano-scale ultrafine powder material.

[0045] As an example, the D50 of the powder material is 20 μm, 22 μm, 24 μm, 26 μm, 28 μm, 30 μm, 32 μm, 34 μm, 36 μm, 38 μm, 40 μm, etc.

[0046] As an example, the grain size of the powder material is 70 nm, 65 nm, 60 nm, 55 nm, 50 nm, 45 nm, 40 nm, 35 nm, 30 nm, 25 nm, 20 nm, 15 nm, 10 nm, etc.

[0047] In some embodiments of the present application, at least one of the following is satisfied: (i) the refiner comprises at least one of silicon and silicon dioxide; (ii) Raw materials include: a combination of silicon and aluminum.

[0048] In the embodiment of the present application, at least one of silicon and silicon dioxide is used as a refiner. Furthermore, silicon is used as a refiner, which has the characteristics of high temperature resistance and chemical inertness. It will not melt in the high temperature environment of preparing powder materials, providing stable crystal seeds, and chemical inertness, ensuring that chemical reactions will not occur in the preparation process and finished materials, affecting the performance of the powder materials. The refiner provided in this embodiment is easy to process into nano-scale ultrafine powders, such as reaching less than 50 nm, which is conducive to effectively realizing the refinement of powder materials. In addition, especially silicon as a refiner can reduce the introduction of impurities, avoid contaminating the powder material, and affect the performance of the powder material.

[0049] In the embodiment of the present application, the raw material is a combination of silicon and aluminum.

[0050] A combination of silicon and aluminum is used as raw materials, and aluminum is used as the base material. The alloy phase of silicon and aluminum is simple, the silicon phase and the aluminum phase are distinct, and it is not easy to form other aluminum-silicon compounds; and the effect is better when used in combination with a refiner, the grain size of the crystal is smaller, and the particles of the powder are smaller.

[0051] In some embodiments of the present application, the amount of the refiner added is 0.5% to 1% of the mass of the raw material; and / or the average particle size of the refiner is 5 nm to 20 nm.

[0052] In the embodiment of the present application, the amount of the refiner added meets the above conditions, which can effectively refine the powder material and ensure low production costs. In specific examples, the amount of the refiner added is 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, etc. of the mass of the raw material.

[0053] In the embodiments of the present application, the average particle size of the refiner meets the above conditions. The smaller the particle size of the refiner, the more conducive it is to the grain refinement of the raw material. At the same time, it is to avoid increasing the preparation cost and storage cost of the refiner, and to avoid problems such as agglomeration and diffusion difficulty after the refiner with too small a particle size is added to the melt. For example, nano-silicon with too small a particle size is highly active, which will increase the difficulty of production. In the specific example, the average particle size of the refiner is 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, etc.

[0054] In some embodiments of the present application, the average particle size of the refiner is 5 nm to 15 nm.

[0055] In the embodiments of the present application, the average particle size of the refiner meets the above conditions, which is conducive to the effective refinement of the powder material and avoids increasing the difficulty of production.

[0056] In some embodiments of the present application, the raw material is a combination of silicon and aluminum, and the mass percentage of silicon is 10% to 50%.

[0057] In the embodiment of the present application, the silicon content meets the above conditions, and the above raw materials are used to prepare the powder material. When the raw materials are heated to prepare the melt, it is beneficial to ensure that the melt maintains a low viscosity state, so that when cooling, it maintains a good heat dissipation state and avoids excessive grain size. In specific examples, the mass percentage of silicon is 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, etc. of the total mass of the combination.

[0058] In some embodiments of the present application, in the combination of silicon and aluminum, the mass percentage of silicon is 20% to 30% of the total mass of the combination.

[0059] In the embodiment of the present application, the silicon content meets the above conditions, which is conducive to forming a powder material with smaller grains. In specific examples, the mass percentage of silicon is 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, etc. of the total mass of the combination.

[0060] A second aspect of the embodiment of the present application provides a method for preparing a powder material, comprising the steps of: The raw material is heat-treated to obtain a molten body; the raw material comprises: silicon; or a combination of at least one of silicon and aluminum; The melt is mixed with a refiner to obtain a mixed material; the refiner comprises at least one of silicon, aluminum oxide, cerium oxide, titanium dioxide, lanthanum oxide, silicon dioxide, zirconium dioxide, nickel oxide, iron oxide, silver, aluminum and iron; and the amount of the refiner added is 0.01% to 2% of the mass of the raw material; The mixed material is cooled to obtain a powder material.

[0061] The method for preparing the powder material provided in the embodiment of the present application adopts a new refiner, which is used in combination with the raw material of the silicon-containing material, and has a good refinement effect on the silicon-containing material.

[0062] The embodiment of the present application provides a method for preparing a powder material, and the raw material used is a silicon-containing material, which is specifically divided into two types: one is silicon; the other is a combination of silicon and aluminum. When the above raw materials are used to prepare the powder material, in the process of heating to prepare the melt, the silicon in the raw material is first precipitated and becomes solid. By adding a refiner that mainly acts on silicon, it can serve as a nucleation point for the precipitated silicon, promote the refinement of silicon grains, and obtain a nano-level ultrafine powder material.

[0063] The refiner used in the preparation method provided in the embodiment of the present application has the characteristics of high temperature resistance and chemical inertness. It will not melt in the high temperature environment of preparing the powder material, providing a stable seed, and is chemically inert, ensuring that no chemical reaction will occur during the preparation process and in the finished material, which will affect the performance of the powder material. The refiner provided in this embodiment is easy to process into nano-scale ultrafine powders, such as reaching less than 50 nm, which is conducive to effectively achieving the refinement of the powder material.

[0064] In the embodiment of the present application, the amount of refiner added meets the above conditions, which is conducive to promoting the refinement of the powder material and ensuring low production costs. If too little refiner is added, the number of nucleation points is small, and the grain size of the formed powder material will become larger; if too much refiner is added, other refiners other than silicon will cause the impurity content or oxygen content in the material to increase, and a large amount of nano-silicon used in a high temperature environment is prone to safety problems and excessive use costs. In a specific example, the amount of refiner added is 0.01%, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, etc. of the mass of the raw material.

[0065] In addition, the refiner used in the preparation method provided in the embodiment of the present application is relatively easy to obtain and has basically no corrosive effect on the equipment.

[0066] In some embodiments of the present application, at least one of the following is satisfied: (i) the refiner comprises at least one of silicon and silicon dioxide; (ii) Raw materials include: a combination of silicon and aluminum.

[0067] In the embodiment of the present application, at least one of silicon and silicon dioxide is used as a refiner, and further, silicon is used as a refiner. It has the characteristics of high temperature resistance and chemical inertness. It will not melt in the high temperature environment of preparing powder materials, providing stable crystal seeds, and chemical inertness, ensuring that chemical reactions will not occur in the preparation process and finished materials, affecting the performance of the powder materials. The refiner provided in this embodiment is easy to process into ultrafine powders at the nanometer level, such as reaching less than 50 nm, which is conducive to effectively realizing the refinement of powder materials. In addition, especially silicon as a refiner can reduce the introduction of impurities, avoid contaminating the powder material, and affect the performance of the powder material.

[0068] In the embodiment of the present application, the raw material is a combination of silicon and aluminum.

[0069] A combination of silicon and aluminum is used as raw materials, and aluminum is used as the base material. The alloy phase of silicon and aluminum is simple, the silicon phase and the aluminum phase are distinct, and it is not easy to form other aluminum-silicon compounds. Moreover, the effect is better when used in combination with a refiner, the crystal grain size is smaller, the powder particles are smaller, and the silicon particles become very small.

[0070] In some embodiments of the present application, the amount of the refiner added is 0.5% to 1% of the mass of the raw material; and / or the average particle size of the refiner is 5 nm to 20 nm.

[0071] In the embodiment of the present application, the amount of the refiner added meets the above conditions, which can effectively refine the powder material and ensure low production costs. In specific examples, the amount of the refiner added is 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, etc. of the mass of the raw material.

[0072] In the embodiments of the present application, the average particle size of the refiner meets the above conditions. The smaller the particle size of the refiner, the more conducive it is to the grain refinement of the raw material. At the same time, it is to avoid increasing the preparation cost and storage cost of the refiner, and to avoid problems such as agglomeration and diffusion difficulty after the refiner with too small a particle size is added to the melt. For example, nano-silicon with too small a particle size is highly active, which will increase the difficulty of production. In the specific example, the average particle size of the refiner is 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, etc.

[0073] In some embodiments of the present application, the average particle size of the refiner is 5 nm to 15 nm.

[0074] In the embodiments of the present application, the average particle size of the refiner meets the above conditions, which is conducive to the effective refinement of the powder material and avoids increasing the difficulty of production.

[0075] In some embodiments of the present application, the raw material is a combination of silicon and aluminum, and the mass percentage of silicon is 10% to 50%.

[0076] In the embodiment of the present application, the silicon content meets the above conditions, and the above raw materials are used to prepare the powder material. When the raw materials are heated to prepare the melt, it is beneficial to ensure that the melt maintains a low viscosity state, so that when cooling, it maintains a good heat dissipation state and avoids excessive grain size. In specific examples, the mass percentage of silicon is 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, etc. of the total mass of the combination.

[0077] In some embodiments of the present application, in the combination of silicon and aluminum, the mass percentage of silicon is 20% to 30% of the total mass of the combination.

[0078] In the embodiment of the present application, the silicon content meets the above conditions, which is conducive to forming a powder material with smaller grains. In specific examples, the mass percentage of silicon is 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, etc. of the total mass of the combination.

[0079] In some embodiments of the present application, the preparation method satisfies at least one of the following: (i) in the step of heat treating the raw material, the control parameters include: a temperature of 680°C to 1200°C; (ii) in the step of heat treating the raw material, the heat treatment temperature is within 150° C. higher than the melting temperature of the raw material; (iii) In the step of mixing the melt with the refiner, the temperature is maintained at the heat treatment temperature after mixing for a period of 10 minutes to 5 hours.

[0080] In the embodiment of the present application, in the step of heat treating the raw materials, based on the melting phase diagram of silicon-aluminum alloy, the temperature is controlled to be 680°C~1200°C, so that the silicon and aluminum combined raw materials can be heated to at least partially molten state. In a specific example, the control temperature is 680°C, 700°C, 710°C, 720°C, 730°C, 740°C, 750°C, 760°C, 770°C, 780°C, 790°C, 800°C, 810°C, 820°C, 830°C, 840°C, 850°C, 860°C, 870°C, 880°C, 890°C, 900°C, 910°C, 920°C, 930°C, 940°C, 950°C, 960°C, 970°C, 980°C, 990°C, 1000°C, 1010°C, 1020°C, 1030°C, 1040°C, 1050°C, 1060°C, 1070°C ℃, 1080 ℃, 1090 ℃, 1100 ℃, 1200 ℃, etc.

[0081] In the embodiment of the present application, the temperature of the heat treatment is controlled to be higher than the melting temperature of the raw material by less than 150 ° C, which is conducive to ensuring that the raw material is fully melted, and at the same time, it is conducive to avoiding the heat treatment temperature being too high above the melting temperature, resulting in prolonged cooling time and grain growth; in addition, it will also increase costs. In a specific example, the temperature of the heat treatment is controlled to be higher than the melting temperature of the raw material by 150 ° C, 140 ° C, 130 ° C, 120 ° C, 110 ° C, 100 ° C, 90 ° C, 80 ° C, 70 ° C, 60 ° C, 50 ° C, 40 ° C, 30 ° C, 20 ° C, etc. Further, the temperature of the heat treatment is controlled to be 100 ° C to 150 ° C higher than the melting temperature of the raw material.

[0082] In the embodiment of the present application, after adding the refiner to the melt, the temperature is maintained for 10 min to 5 h under the condition that the melt will not condense and solidify, so as to promote full contact between the powdered refiner and the melt, uniform growth of the grains, and maintain high production efficiency. In the specific example, the maintenance time is 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, and 5 h.

[0083] Furthermore, in the step of mixing the melt with the refining agent, the temperature after mixing is maintained at a heat treatment temperature, i.e., 700°C to 1100°C, and the holding time is 30 min to 120 min. In specific examples, the holding time is 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, 65 min, 70 min, 75 min, 80 min, 85 min, 90 min, 95 min, 100 min, 105 min, 110 min, 115 min, 120 min, etc.

[0084] In some embodiments of the present application, in the step of cooling the mixed material, the cooling method adopted includes gas atomization, water atomization or centrifugal atomization.

[0085] Further, the cooling gas medium of the atomization includes an inert gas, and the inert gas includes nitrogen or argon. Further, the cooling gas medium of the atomization is nitrogen.

[0086] Furthermore, the air flow sweep speed of the atomized cooling gas medium is greater than 10 m 3 / min.

[0087] Furthermore, the cooling method is gas atomization, which is not easy to cause oxidation of the material, and the cooling process can be controlled by adjusting the air flow speed and the amount of air introduced, which has strong controllability and is conducive to obtaining a more fine powder material.

[0088] In some embodiments of the present application, a method for preparing a powder material comprises the steps of: S1000. Heat-treating the raw materials to obtain a molten body. The raw materials include: silicon; or a combination of silicon and aluminum. Specifically, the raw materials can be placed in a heating furnace and heated to a set temperature to be in a molten state.

[0089] S2000. The melt is mixed with a refiner to obtain a mixed material; the refiner includes at least one of silicon, aluminum oxide, cerium oxide, titanium dioxide, lanthanum oxide, silicon dioxide, zirconium dioxide, nickel oxide, iron oxide, silver, aluminum and iron. The refiner is added to the melt and the above temperature is maintained for a certain period of time, and the next step is performed after the mixture is uniformly mixed and the grains grow uniformly.

[0090] S3000. Cool the mixed material to obtain a powder material. Use a cooling device to cool the melt into a powder material.

[0091] A third aspect of the embodiments of the present application proposes an electrode material, wherein the raw materials for preparing the electrode material include the above-mentioned powder material, or include the powder material prepared by the above-mentioned preparation method.

[0092] The electrode material provided in the embodiment of the present application is prepared from raw materials including the above-mentioned powder material, or including the powder material prepared by the above-mentioned preparation method, and the powder material has a smaller grain size and a smaller powder particle size, which is conducive to obtaining an electrode with good electrical properties. Specifically, for example, a smaller grain size can increase the specific surface area of ​​the material, thereby increasing the contact area with the electrolyte, which helps to improve the charge and discharge efficiency and rate capability of the battery. In addition, fine grains can reduce volume expansion and contraction during the charge and discharge process, thereby improving the structural stability and cycle life of the negative electrode material.

[0093] In some embodiments of the present application, the electrode material is a negative electrode active material. In a specific example, a silicon aluminum alloy powder material is used as a negative electrode active material, which does play a role in removing and inserting lithium in a lithium-ion battery.

[0094] It should be noted that the features and advantages described above for the preparation methods of the powder materials of the first aspect and the second aspect of the present application are also applicable to the electrode materials of the third aspect of the present application and will not be repeated here.

[0095] The scheme of the present application will be explained below in conjunction with the embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If no specific technology or conditions are indicated in the embodiments, the technology or conditions described in the literature in this area or the product specification are carried out. The reagents used or the instruments that do not indicate the manufacturer are all conventional products that can be obtained commercially.

[0096] Example 1 The preparation method of powder material is: Step 1: In a nitrogen atmosphere, an aluminum ingot and a silicon ingot (both commercially available) with a mass ratio of 4:1 are placed in a medium frequency induction furnace, that is, in the combined raw materials of silicon and aluminum, the mass percentage of silicon is 20%, and heated to 800°C to a molten state to obtain a melt.

[0097] Step 2: Add 0.5% of the raw material mass of a refiner (silicon powder, with an average particle size of 10 nm) to the melt obtained in step 1, stir and mix evenly, and maintain the heating temperature of step 1 for 1 hour to obtain a melt (the refiner remains in a solid state).

[0098] Step 3: In the gas atomization equipment (using the experimental atomization powder making equipment of Zhuzhou Shuangling Technology Co., Ltd.), nitrogen is used as the cooling gas medium, and the air flow sweeping speed is 12 m 3 / min, blowing the molten metal into metal powder.

[0099] Example 2-Example 32 The preparation method of the powder material in Examples 2 to 32 adopts the preparation method of Example 1, and the specific composition, dosage and parameters are shown in Table 1.

[0100] Comparative Example 1-Comparative Example 5 The preparation method of the powder materials in Comparative Examples 1 to 5 adopts the preparation method of Example 1, and the specific composition, dosage and parameters are shown in Table 1.

[0101]

[0102] Note: In Table 1, the refiners used in Comparative Examples 1-3 are as follows: Titanium-boron composite modifier: Sichuan Lande High-tech Industry Co., Ltd., titanium-boron refiner AX201.

[0103] Phosphate composite modifier: Xuzhou Siyuan Aluminum Co., Ltd., phosphate composite modifier, SY-PB1.

[0104] Aluminum-copper alloy modifier: Sichuan Lande High-tech Industry Co., Ltd., copper additive-Cu75.

[0105] Performance Testing 1. Test method: 1. Powder material particle size D 50 (D 50 Refers to the particle size corresponding to the cumulative particle size distribution percentage of a sample reaching 50%): Use a particle size distribution instrument to test, and the equipment automatically outputs D 50 size.

[0106] 2. Grain size of powder materials: In-situ transmission electron microscopy is used for characterization testing and analysis of particle size.

[0107] 2. Test results: The performance test results of Examples 1-32 and Comparative Examples 1-5 are shown in Table 2.

[0108]

[0109] The refiner provided in this embodiment is convenient for processing to obtain nano-scale ultrafine alloy powder, and the grain size can reach below 70 nm, which is conducive to effectively realizing the refinement of powder materials.

[0110] As shown in Table 2, in the embodiment of the present application, the amount of the refiner added meets the above conditions, which is conducive to promoting the refinement of the powder material and ensuring low production costs. If too little refiner is added, the number of nucleation points is small, and the grain size of the formed powder material will become larger; if too much refiner is added, other refiners except silicon will cause the impurity content or oxygen content in the material to increase, and a large amount of nano-scale refiners (i.e., nano-silicon) are used in a high temperature environment, which is easy to cause safety problems and high use costs.

[0111] like Figure 1 and Figure 2 As shown, the silicon refiner is added during the preparation of the silicon aluminum alloy powder material, and the obtained grain size is smaller ( Figure 1 As shown), and the particle size of the powder is small ( Figure 2 As shown in the figure), the effect of effectively refining the powder material is achieved.

[0112] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A powder material, characterized in that: Including raw materials and refiners; The refiner comprises at least one of silicon, aluminum oxide, cerium oxide, titanium dioxide, lanthanum oxide, silicon dioxide, zirconium dioxide, nickel oxide, iron oxide, silver, aluminum and iron; The raw material includes: silicon; or a combination of silicon and aluminum; The amount of the refiner added is 0.01% to 2% of the mass of the raw material.

2. The powder material according to claim 1, characterized in that: At least one of the following is met: (i) the refiner comprises at least one of silicon and silicon dioxide; (ii) The raw material comprises: a combination of silicon and aluminum.

3. The powder material according to claim 1 or 2, characterized in that: The amount of the refiner added is 0.5% to 1% of the mass of the raw material; and / or the average particle size of the refiner is 5 nm to 20 nm.

4. The powder material according to claim 3, characterized in that: The raw material is a combination of silicon and aluminum, and the mass percentage of the silicon is 10% to 50%.

5. The powder material according to claim 1, characterized in that: The D50 of the powder material is 20 μm to 40 μm, and / or the grain size of the powder material is less than 70 nm.

6. A method for preparing a powder material, characterized in that: Includes steps: Heat treating raw materials to obtain a molten body; the raw materials include: silicon; or a combination of silicon and aluminum; The melt is mixed with a refiner to obtain a mixed material; the refiner comprises at least one of silicon, aluminum oxide, cerium oxide, titanium dioxide, lanthanum oxide, silicon dioxide, zirconium dioxide, nickel oxide, iron oxide, silver, aluminum and iron; and the amount of the refiner added is 0.01% to 2% of the mass of the raw material; The mixed material is cooled to obtain a powder material.

7. The method for preparing a powder material according to claim 6, characterized in that: At least one of the following is met: (i) the refiner comprises at least one of silicon and silicon dioxide; (ii) The raw material comprises: a combination of silicon and aluminum.

8. The method for preparing a powder material according to claim 6 or 7, characterized in that: The amount of the refiner added is 0.5% to 1% of the mass of the raw material; and / or the average particle size of the refiner is 5 nm to 20 nm.

9. The method for preparing a powder material according to claim 8, characterized in that: The raw material is a combination of silicon and aluminum, and the mass percentage of the silicon is 10% to 50%.

10. The method for preparing a powder material according to claim 7, characterized in that: The preparation method satisfies at least one of the following: (i) In the step of heat treating the raw material, the control parameters include: a temperature of 680°C to 1200°C; (ii) in the step of heat treating the raw material, the heat treatment temperature is within 150° C. higher than the melting point of the raw material; (iii) In the step of mixing the melt with the refiner, the temperature after mixing is maintained at the heat treatment temperature for a period of 10 min to 5 h.

11. An electrode material, characterized in that: The preparation raw material includes the powder material according to any one of claims 1 to 5, or includes the powder material prepared by the preparation method according to any one of claims 6 to 10.

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