KR-102963918-B1 - Uniformly modified silicon oxide cathode material, method of manufacturing the same, and application

KR102963918B1KR 102963918 B1KR102963918 B1KR 102963918B1KR-102963918-B1

Abstract

The present invention relates to a uniformly modified silicon oxide cathode material, a method for manufacturing the same, and applications. The silicon oxide cathode material comprises silicon oxide and carbon atoms, wherein the carbon atoms are uniformly distributed within the silicon oxide at the atomic level. The carbon atoms bond with silicon atoms to form amorphous Si-C bonds, and there is no crystallization peak of SiC in the X-ray diffraction spectrum (XRD). In a solid-state nuclear magnetic resonance (NMR) test of the uniformly modified silicon oxide cathode material, according to the 29 Si NMR pattern, a Si-C resonance peak exists between -10 ppm and -20 ppm. The average particle size D 50 of the silicon oxide cathode 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. The present invention uniformly distributes carbon atoms at the atomic level in silicon oxide using a gaseous method, and the material exhibits small volume expansion during the lithium extraction and insertion process and has a high conductivity coefficient for lithium ions, thereby improving the material's cycle performance and scaling performance.

Inventors

루오,페이

Assignees

톈무레이크 엑설런트 애노드 머티리얼즈 컴퍼니 리미티드

Dates

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

Claims (10)

As a silicon oxide (SiO) cathode material, It comprises silicon oxide and carbon atoms, wherein the carbon atoms are uniformly distributed in the silicon oxide at an atomic level; Carbon atoms bond with silicon atoms to form amorphous Si-C bonds, and there are no crystallization peaks of SiC in the X-ray diffraction spectrum (XRD); In the solid-state nuclear magnetic resonance (NMR) spectroscopy of the uniformly modified silicon oxide cathode material above, according to the 29 Si NMR pattern, a Si-C resonance peak exists between -10 ppm and -20 ppm; The average particle size D 50 of the silicon oxide cathode 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 above carbon atoms accounts for 0.1%-40% of the mass of silicon oxide, and A uniformly modified silicon oxide cathode material characterized by having carbon atoms uniformly dispersed at the atomic level within the silicon oxide material, which is obtained by heating silicon and silica under reduced pressure conditions to generate silicon-oxygen vapor, then passing a carbon-containing solution through it at 1000℃-1800℃ to vaporize it, mixing it with the silicon-oxygen vapor, and then condensing and depositing it on a water-cooled substrate.
In paragraph 1, The outer surface of the above silicon oxide cathode material further has a carbon coating layer; A silicon oxide cathode material characterized in that the mass of the carbon coating layer accounts for 0-20% of the mass of the silicon oxide.
In paragraph 2, The mass of the above carbon atoms accounts for 0.5%-10% of the mass of silicon oxide; A silicon oxide cathode material characterized in that the mass of the carbon coating layer accounts for 0-10% of the mass of the silicon oxide.
A method for manufacturing a uniformly modified silicon oxide cathode material according to any one of claims 1 to 3, The above manufacturing method is, A step of uniformly mixing silicon and silica powders, placing them in a crucible, and heating under reduced pressure conditions to obtain steam containing silicon and oxygen elements; A step of passing a solution of a carbon-containing material through the crucible and vaporizing the solution of the carbon-containing material to obtain mixed vapor; The method includes the step of cooling and depositing a mixed vapor on a water-cooled substrate, and crushing the deposited material to obtain a silicon oxide material, i.e., a silicon oxide cathode material, in which carbon atoms are uniformly dispersed and distributed at the atomic level within it. The above heating temperature is 1000℃-1800℃, and The solution of the above carbon-containing material is, It comprises a mixed solution of one or more of an organic solution, an organic solution in which a solute is dissolved, and an aqueous carbon-containing solution, and Specifically, the solution of the above carbon-containing material is, A manufacturing method characterized by comprising one or more of benzene, ethanol, ether, acetone, acetonitrile, pyridine, tetrahydrofuran, a tetrahydrofuran solution in which polyvinylidene fluoride is dissolved, a dimethylformamide solution in which polyacrylonitrile is dissolved, a dimethyl sulfoxide solution in which polyurethane is dissolved, a graphene aqueous dispersion, a carbon black aqueous dispersion, or a bitumen emulsion.
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In paragraph 4, The above manufacturing method is, A manufacturing method characterized by further including the step of obtaining the silicon oxide cathode material by carbon coating the above-mentioned crushed material and then classifying it.
In Paragraph 7, The above carbon coating is, A manufacturing method characterized by including at least one of a vapor phase coating, a liquid phase coating, and a solid phase coating.
A cathode sheet comprising a silicon oxide cathode material according to any one of claims 1 to 3.
A lithium battery comprising the negative electrode sheet of claim 9.

Description

Uniformly modified silicon oxide cathode material, method of manufacturing the same, and application Cross-citation of related applications This application claims priority to the Chinese patent application No. 202110522885.1, filed with the Chinese Intellectual Property Office on May 13, 2021, titled “Uniformly modified silicon oxide cathode material and method for manufacturing the same and application.” The present invention relates to the field of materials technology, and in particular to a uniformly modified silicon oxide cathode material and a method for manufacturing the same and its applications. The energy density of lithium-ion batteries has a positive correlation with the gram capacity of the anode and cathode materials. The gram capacity of high-grade graphite currently used as anode material has already reached 360–365 mAh/g, approaching the theoretical gram capacity of 372 mAh/g. Therefore, from the perspective of anode materials, it is necessary to develop anode materials with higher gram capacities to improve battery cell energy density. Silicon-based anodes achieve high gram capacities by implementing lithium insertion and extraction processes through lithium-ion alloying and dealloying, but they exhibit rapid volume expansion. Optimization of material design and battery systems is the primary method for resolving the shortcomings of silicon-based anode materials and achieving commercialization. In material design, certain results have been achieved by modifying silicon oxide. Silicon oxide suffers from poor conductivity, constant volume expansion during cycling, and the continuous growth of SEI films. Carbon coating can, on the one hand, protect silicon oxide to act as a buffer layer against particle expansion, while on the other hand, it can increase particle conductivity, facilitate lithium ion transport, and reduce the charge transfer resistance of the electrode. To further enhance the fast charging performance of batteries, the conductivity within the particles must be improved. However, since the conductivity within silicon oxide particles cannot be improved through surface modification, internal conductivity must also be enhanced to meet the practical demand for fast charging in future applications. 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 uniformly modified silicon oxide cathode material provided by an embodiment of the present invention; FIG. 2 is a 29 Si NMR pattern of a uniformly modified silicon oxide cathode material provided by Example 1 of the present invention; Figure 3 is an XRD pattern of a uniformly modified silicon oxide cathode material 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. The silicon oxide cathode material of the present invention comprises silicon oxide and carbon atoms, wherein carbon atoms are uniformly distributed in the silicon oxide at the atomic level. Carbon atoms bond with silicon atoms to form amorphous Si-C bonds, and there is no crystallization peak of SiC in the X-ray diffraction spectrum (XRD). In the solid-state nuclear magnetic resonance (NMR) spectroscopy of the uniformly modified silicon oxide cathode material, according to the 29 Si NMR pattern, a Si-C resonance peak exists between -10 ppm and -20 ppm. The average particle size D 50 of the silicon oxide cathode particles is 1 nm to 100 μm, and the specific surface area is 0.5 m² /g to 40 m² /g. The mass of carbon atoms accounts for 0.1% to 40% of the mass of the silicon oxide. Preferably, the mass of carbon atoms accounts for 0.5% to 10% of the mass of the silicon oxide. The outer layer of the above material may be further coated with a carbon coating layer, the mass of the carbon coating layer accounts for 0-20% of the mass of the silicon oxide, and preferably, the mass of the carbon coating layer accounts for 0-10% of the mass of the silicon oxide. The uniformly modified silicon oxide cathode material of the present invention can be obtained through the following manufacturing method, the main method steps are illustrated in FIG. 1 and include the following steps. In step 110, silicon and silica powders are uniformly mixed according to the required amount, placed in a crucible, and heated under reduced pressure conditions to obtain steam containing silicon and oxygen elements. Here, the heating temperature is 1000℃-1800℃. In step 120, a solution of carbon-containing material is passed through the crucible, and the solution of carbon-containing material is vaporized to obtain mixed steam. Specifically, the solution of the carbo