JP-2026514314-A - Negative electrode material and method for manufacturing the same, battery

JP2026514314AJP 2026514314 AJP2026514314 AJP 2026514314AJP-2026514314-A

Abstract

This application relates to the technology of negative electrode materials, and more particularly to negative electrode materials, methods for manufacturing the same, and batteries. The negative electrode material contains an active material, and the surface density of the negative electrode material is β, where β is ≥ 80%, however, β is measured by the following measurement method: 1 g of mass m of negative electrode material is immersed in a hydrofluoric acid solution with a mass fraction of 20%, immersed for 1 hour, washed and dried to obtain 2 g of material, and the surface density of the negative electrode material β = m²/m1 × 100% is calculated. The negative electrode material of this application has a high surface density, which reduces the amount of negative electrode material dissolved during the cycle process, further reduces the reaction between dissolved silicon particles and the electrolyte, effectively lowers the gas generation value of the negative electrode material, and the total pore volume of the negative electrode material is small and the structure is tighter, which reduces the amount of electrolyte penetration into the negative electrode material during the cycle process and improves the cycle performance of the negative electrode material. [Selection Diagram] Figure 1

Inventors

何鵬
肖称茂
劉明杰
任建国
賀雪琴
陳▲ギ▼
劉儀嘉

Assignees

貝特瑞新材料集団股▲フン▼有限公司

Dates

Publication Date: 20260511
Application Date: 20240628
Priority Date: 20230928

Claims (15)

A negative electrode material, wherein the negative electrode material contains an active material, the surface density of the negative electrode material is β, and β is ≥ 80%. However, the β mentioned above is measured by the following measurement method: A negative electrode material characterized by immersing a negative electrode material with a mass of m 1 g in a hydrofluoric acid solution with a mass fraction of 20%, immersing for 1 hour, washing and drying to obtain a material with a mass of m 2 g, and calculating the surface density β = m 2 / m 1 × 100% of the negative electrode material.
The negative electrode material according to claim 1, characterized in that the active material comprises a carbon substrate and silicon particles, and at least some of the silicon particles are located inside the particles of the carbon substrate.
The negative electrode material according to claim 1, characterized in that the negative electrode material has pores, the pores include micropores and mesopores, wherein the ratio of the pore volume of the micropores to the pore volume of the mesopores is (1-45):(55-99).
The aforementioned negative electrode material is (1) The characteristic of micropores is that the pore volume occupancy is ≤10%, (2) The characteristic of mesopores is that the pore volume occupancy rate is ≥ 80%, (3) The negative electrode material according to claim 3, characterized in that it has at least one of the following features: the pore volume occupancy rate of the macropores is ≤20%.
The negative electrode material has holes, and the negative electrode material is (1) The negative electrode material has the characteristic that the total pore volume is 0.001 cm³ /g to 0.1 cm³ /g, (2) The negative electrode material has the characteristic that the average pore size is 0.4 nm to 50 nm, (3) The negative electrode material according to claim 1, characterized in that it has at least one of the following characteristics: (3) The volume occupancy rate of the total pore volume of pores with a pore diameter of 10 nm or less in the negative electrode material is ≥ 80%.
The aforementioned negative electrode material is (1) In the negative electrode material from which silicon particles have been removed, the volume occupancy rate in the total pore volume of pores with a pore size of 2 nm or less is ≥ 70%, (2) The negative electrode material from which silicon particles have been removed has the characteristic that the volume occupancy rate of the total pore volume of pores with a pore size of 5 nm or less is ≥ 85%, (3) The negative electrode material from which silicon particles have been removed has the characteristic that the volume occupancy rate of the total pore volume of pores with a pore diameter of 10 nm or less is ≥ 95%, (4) The specific surface area of the negative electrode material from which silicon particles have been removed is 500 m² /g to 2000 m² /g, (5) The negative electrode material according to claim 5, characterized in that the total pore volume of all pores in the negative electrode material from which silicon particles have been removed is 0.5 cm³ /g to 1.5 cm³ /g, and has at least one of the above characteristics.
The aforementioned negative electrode material is (1) The silicon particles are characterized by containing at least one of the following: crystalline silicon, silicon oxide, amorphous silicon, silicon alloy, and crystalline silicon/amorphous silicon composite particles. (2) The average particle size of the silicon particles is 0.1 nm to 50 nm, (3) The anode material according to claim 2, characterized in that the carbon substrate contains at least one of the following: artificial graphite, natural graphite, amorphous carbon, activated carbon, mesocarbon microbeads, carbon nanotubes, carbon nanofibers, porous carbon, and graphene.
The aforementioned negative electrode material is (1) The negative electrode material has a characteristic of having a mass content of silicon element of 20% to 60%, (2) The negative electrode material is characterized in that the mass content of carbon is 20% to 80%, (3) The negative electrode material contains trace metal elements, and the trace metal elements are characterized by containing at least one of Fe, Co, Ni, Cr, Zn, Cu, and Al. (4) The negative electrode material according to claim 2, characterized in that the negative electrode material has at least one of the following characteristics: containing trace metal elements with a mass occupancy of ≤200 ppm.
The anode material according to claim 1, characterized in that the average gas generation amount of the anode slurry produced from the anode material is ≤1 mL/g/day when left in a 25°C environment for 7 days.
The anode material according to any one of claims 1 to 9, characterized in that the surface of the anode material has a coating layer, and the material of the coating layer includes a carbon material.
The aforementioned negative electrode material is (1) The carbon material is characterized by containing at least one of amorphous carbon and graphitized carbon, (2) The coating layer has the characteristic of having a thickness of 1 nm to 300 nm, (3) The anode material according to claim 10, characterized in that the mass occupancy rate of the coating layer in the anode material is ≤10%.
The aforementioned negative electrode material is (1) The negative electrode material has the characteristic that the median particle size is ≤ 10 μm, (2) The negative electrode material according to any one of claims 1 to 9, characterized in that the particle size distribution of the negative electrode material satisfies 0.9 ≤ (D 90 - D 10 ) / D 50 ≤ 5, and at least one of the above.
The aforementioned negative electrode material is (1) The negative electrode material has the characteristic that its specific surface area is ≤ 10 m² /g, (2) The compacted density of the negative electrode material is 0.8 g/ cm³ to 1.3 g/ cm³ , (3) The anode material according to any one of claims 1 to 9, characterized in that the tap density of the anode material is 0.5 g/ cm³ to 1.5 g/ cm³ .
The negative electrode material according to claim 1, characterized in that the powder conductivity of the negative electrode material at a pressure of 20 kN is 0.5 S/cm to 5 S/cm.
A battery comprising the negative electrode material described in any one of claims 1 to 14.

Description

This application relates to the technology of negative electrode materials, and more specifically, to negative electrode materials, methods for manufacturing the same, and batteries. Lithium-ion batteries have advantages such as high energy density, long service life, and no environmental pollution, and are widely used in the 3C (Commercial, Consumer, and Industrial) sectors. With market development, lithium-ion batteries are not only widely used in mobile devices such as smartphones and portable computers, but are also being applied to large-scale equipment such as electric vehicles and power tools. To improve the energy density of batteries, research and development of silicon-based anode materials are maturing rapidly. While silicon-based anode materials include a silicon-based active material and its surface coating layer, conventional silicon-based anode materials have poor coating effectiveness. During the manufacturing process of lithium-ion batteries, dissolved silicon particles come into contact with the electrolyte, leading to gas generation. Therefore, reducing the reaction between silicon particles and the electrolyte and lowering gas generation is a problem that needs to be solved urgently. This is a scanning electron microscope (SEM) image of the negative electrode material manufactured in Example 1 of the present application.This is an XRD diagram of the negative electrode material manufactured in Embodiment 1 of the present application.This is the initial charge-discharge curve of the negative electrode material manufactured in Example 1 of the present invention.This is the cycle performance curve of the negative electrode material manufactured according to Example 1 of the present application. The embodiments described below with reference to the drawings are illustrative and intended solely for interpretation purposes and should not be construed as limiting the present application. Lithium-ion batteries have advantages such as high energy density, long service life, and no environmental pollution, and are widely used in the 3C (Commercial, Consumer, and Industrial) sectors. With market development, lithium-ion batteries are not only widely used in mobile devices such as smartphones and portable computers, but are also being applied to large-scale equipment such as electric vehicles and power tools. To improve the energy density of batteries, research and development of silicon-based anode materials are maturing rapidly. While silicon-based anode materials include a silicon-based active material and its surface coating layer, conventional silicon-based anode materials have poor coating effectiveness. During the manufacturing process of lithium-ion batteries, dissolved silicon particles come into contact with the electrolyte, leading to gas generation. In a first embodiment, the present application provides a negative electrode material comprising an active material, wherein the surface density of the negative electrode material is β, and β is ≥ 80%. However, the β mentioned above is measured by the following measurement method: A negative electrode material with a mass of m1 g is immersed in a hydrofluoric acid solution with a mass fraction of 20% for 1 hour, then washed and dried to obtain m2 g of material. The surface density β of the negative electrode material is then calculated as m2 / m1 × 100%. In the above solution, the negative electrode material contains an active material, and the surface density β of the negative electrode material is ≥80%. Within this range, it is possible to reduce the amount of negative electrode material dissolved during the cycle process, further reduce the reaction between the active material dissolved from the negative electrode material and the electrolyte, effectively lower the gas generation value of the negative electrode material, and reduce side reactions due to contact between the electrolyte and the active material in the negative electrode material, thereby improving the cycle performance of the lithium-ion battery manufactured with the negative electrode material. In some embodiments, the surface density of the negative electrode material is ≥ 80%, specifically 80%, 82%, 85%, 86%, 89%, 90%, 92%, 95%, or 98%, and of course, other values within the above range. As can be understood, ideally, the surface density of the negative electrode material is 100%, in which case the surface density of the negative electrode material is high, and when the negative electrode material is placed in the dissolution solution, the active material in the negative electrode material does not dissolve, and furthermore, the dissolved active material does not come into contact with the dissolution solution and react. However, negative electrode materials manufactured by conventional methods have insufficient surface density, and the negative electrode material has a certain amount of dissolution in the dissolution solution, and the dissolved active material is contained