KR-102963942-B1 - Uniformly modified silicon-based lithium-ion battery anode material and method of manufacturing the same and application

KR102963942B1KR 102963942 B1KR102963942 B1KR 102963942B1KR-102963942-B1

Abstract

The present invention relates to a uniformly modified silicon-based lithium-ion battery anode material, a method for manufacturing the same, and applications. The structure of the silicon-based lithium-ion battery anode material is such that carbon atoms are uniformly dispersed and distributed on an atomic scale within a silicon oxide matrix. In focused ion beam-transmission electron microscopy (FIB-TEM) analysis of the silicon-based lithium-ion battery anode material, energy spectrum scans of the particle cross-section reveal that carbon, oxygen, and silicon elements are uniformly distributed within the particles. The average particle size D 50 of the silicon-based lithium-ion battery anode material particles is 1 nm to 100 μm, and the specific surface area is 0.5 m² /g to 40 m² /g. The mass of the carbon atoms accounts for 0.1% to 40% of the mass of the silicon oxide matrix. In the silicon oxide manufacturing process of the present invention, a carbon-containing gas source is introduced, and as the carbon atoms distributed in the silicon oxide belong to a bulk phase distribution, the anode material possesses the advantages of carbon bulk phase doping, thereby improving the conductivity of the material and the cycle stability of the lithium-ion battery.

Inventors

루오,페이

Assignees

톈무레이크 엑설런트 애노드 머티리얼즈 컴퍼니 리미티드

Dates

Publication Date: 20260512
Application Date: 20210810
Priority Date: 20210513

Claims (9)

As a uniformly modified silicon-based lithium-ion battery anode material, The structure of the above silicon-based lithium-ion battery negative electrode material is such that carbon atoms are uniformly distributed at the atomic level in a silicon oxide (SiO) matrix, and In the focused ion beam-transmission electron microscope (FIB-TEM) inspection of silicon-based lithium-ion battery anode materials, according to the energy spectrum scan results of the particle cross-section, carbon, oxygen, and silicon elements are uniformly distributed within the particles, and no local concentration is observed. The average particle size D 50 of the silicon-based lithium-ion battery negative electrode particles is lnm-100μm, and the specific surface area is 0.5m² /g- 40m² /g, and A uniformly modified silicon-based lithium-ion battery negative electrode material characterized in that the mass of the carbon atoms accounts for 0.1% to 40% of the mass of the silicon oxide matrix.
In paragraph 1, The exterior of the above silicon-based lithium-ion battery negative electrode material further has a carbon coating layer; A silicon-based lithium-ion battery negative electrode material characterized in that the mass of the carbon coating layer accounts for 0-20% of the mass of the silicon oxide matrix.
In paragraph 2, The mass of the above carbon atoms accounts for 0.5%-10% of the mass of the silicon oxide matrix; A silicon-based lithium-ion battery negative electrode material characterized in that the mass of the carbon coating layer accounts for 0-10% of the mass of the silicon oxide matrix.
In any one of paragraphs 1 through 3, A method for manufacturing a silicon-based lithium-ion battery negative electrode material is, Under a protective gas atmosphere, a mixed vapor of a carbon-containing gas source, preheated silicon, and silica is subjected to a gas-phase mixing reaction for 1 to 24 hours, wherein the components participating in the gas-phase mixing reaction are the carbon-containing gas source and the preheated silicon and silicon dioxide. A step of obtaining a material using mixed vapor, wherein the mass ratio of silicon to silicon dioxide is 1:1, and carbon atoms are uniformly dispersed in a silicon oxide matrix at an atomic scale; A method for manufacturing a uniformly modified silicon-based lithium-ion battery negative electrode material, characterized by including the step of cooling the above material to room temperature, grinding and sieving it to obtain the silicon-based lithium-ion battery negative electrode material, which is a particle in which carbon atoms are uniformly distributed at the atomic level in a silicon oxide matrix.
In paragraph 4, The above carbon-containing gas source is, A method for manufacturing a uniformly modified silicon-based lithium-ion battery negative electrode material characterized by comprising one or more of methane, propane, butane, acetylene, ethylene, propylene, butadiene, or carbon monoxide.
In paragraph 4, A method for manufacturing a uniformly modified silicon-based lithium-ion battery negative electrode material, characterized by cooling the above material to room temperature, grinding and sieving it, and then further including the step of carbon coating the sieved material and obtaining the negative electrode material after grading.
In paragraph 6, The above carbon coating is, A method for manufacturing a uniformly modified silicon-based lithium-ion battery negative electrode material characterized by including at least one of a vapor phase coating, a liquid phase coating, and a solid phase coating.
A negative electrode sheet characterized by comprising a silicon-based lithium-ion battery negative electrode material according to any one of claims 1 to 3.
A lithium battery comprising the negative electrode sheet of claim 8.

Description

Uniformly modified silicon-based lithium-ion battery anode material and method of manufacturing the same and application Cross-citation of related applications This application claims priority to the Chinese patent application No. 202110524182.2, filed with the Chinese Intellectual Property Office on May 13, 2021, titled “Uniformly modified silicon-based lithium-ion battery negative electrode material and method for manufacturing the same and application thereof.” The present invention relates to the field of materials technology, and in particular to a uniformly modified silicon-based lithium-ion battery negative electrode material and a method for manufacturing the same and its applications. Driven by the demands of economic and social development, natural resources are being ceaselessly consumed. Non-renewable resources such as oil and natural gas are becoming increasingly scarce and are being depleted day by day, and the environmental pollution resulting from the indiscriminate extraction and utilization of oil cannot be overlooked. Therefore, finding clean, eco-friendly, and efficient energy has become a top priority for scientific researchers. Lithium-ion battery technology is one such clean and eco-friendly new energy technology. The anode material is one of the most critical materials in lithium-ion battery technology, and commercially available graphite anodes have already reached their technological limits due to their low gram capacity. Silicon is one of the anode materials with the highest potential to replace it; silicon-based anodes with a specific capacity of 4200 mAh/g and three-dimensional diffusion channels are increasingly demonstrating the advantages of high energy density. While silicon-based anodes can achieve satisfactory energy density, there are also technical bottlenecks associated with the material. Their practical applications are limited due to a series of drawbacks inherent to silicon-based anodes, such as volume expansion effects and poor conductivity. Carbon coating is a relatively common modification method. Commercial silicon oxide currently on the market is generally carbon-coated, and this coating improves the material's cycle performance by enhancing surface conductivity while preventing direct contact with the electrolyte. However, since carbon coating can only alter surface conductivity, internal particle conductivity must also be improved to achieve high-speed charging performance. Technical methods for embodiments of the present invention are described in detail below through drawings and embodiments. FIG. 1 is a flowchart of a method for manufacturing a silicon-based lithium-ion battery negative electrode material provided by an embodiment of the present invention; FIG. 2 is a surface scan of the FIB-TEM energy spectrum of a silicon-based cathode material in which internal carbon atoms are uniformly dispersed and distributed at the atomic level, provided by Example 1 of the present invention; FIG. 3 is a high-resolution electron microscope image of a silicon-based cathode material in which internal carbon atoms are uniformly dispersed at the atomic level, provided by Example 1 of the present invention. The present invention is described in more detail below through the drawings and specific embodiments, but these embodiments are for the purpose of more detailed explanation only and should not be understood as limiting the invention in any way. That is, it is not intended to limit the scope of protection of the present invention. In the silicon-based lithium-ion battery anode material of the present invention, the structure is such that carbon atoms are uniformly dispersed and distributed at the atomic scale within a silicon oxide matrix. In the focused ion beam-transmission electron microscopy (FIB-TEM) analysis of the silicon-based lithium-ion battery anode material, the energy spectrum scan of the particle cross-section shows that carbon, oxygen, and silicon elements are uniformly distributed within the particle. The average particle size D 50 of the silicon-based lithium-ion battery negative electrode particles is lnm-100μm, and the specific surface area is 0.5m² /g- 40m² /g. The mass of carbon atoms accounts for 0.1%-40% of the mass of the silicon oxide matrix. Preferably, the mass of carbon atoms accounts for 0.5%-10% of the mass of the silicon oxide matrix. The outer layer of the above material may be further coated with a carbon coating layer, the mass of which accounts for 0-20% of the mass of the silicon oxide matrix, and preferably, the mass of which accounts for 0-10% of the mass of the silicon oxide matrix. The silicon-based lithium-ion battery negative electrode material of the present invention can be obtained through a manufacturing method comprising the following steps, and the main method steps are as shown in FIG. 1. In step 110, under a protective gas atmosphere, a carbon-containing gas source and a preheated mixed vapor of silicon and silica are