Silicon carbon negative electrode material for lithium ion battery and preparation method thereof

A technology for lithium-ion batteries and negative electrode materials, applied in battery electrodes, circuits, electrical components, etc., can solve problems affecting battery cycle performance and low Coulombic efficiency, achieve good cycle stability, simple preparation process, and inhibit volume expansion effect Effect

Active Publication Date: 2015-10-28
BTR NEW MATERIAL GRP CO LTD
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  • Application Information

AI Technical Summary

Problems solved by technology

However, silicon-based negative electrode materials have huge volume changes during the intercalation and extraction of lithium ions, resulting in the phase separation of electrode active materials and current collectors, which seriously affects the cycle performance of batteries. Oxygen-containing silicon-based materials, especially silicon oxide negative electrode materials, Its application is limited by the low first Coulombic efficiency

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  • Silicon carbon negative electrode material for lithium ion battery and preparation method thereof
  • Silicon carbon negative electrode material for lithium ion battery and preparation method thereof
  • Silicon carbon negative electrode material for lithium ion battery and preparation method thereof

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preparation example Construction

[0027] The preparation method of silicon carbon negative electrode material for lithium ion battery of the present invention comprises the following steps:

[0028] 1. Heat treatment: SiO with a particle size of 1-1000 μm Y , where 0.5≤Y≤1.5, the temperature is raised to 700-1300 °C at a heating rate of 1-2 °C / min, kept for 1-12 hours, and naturally cooled to room temperature. During the heat preservation process, SiO Y A disproportionation reaction will occur at high temperature, and a single silicon phase will be formed, so that the single particle Si is evenly dispersed in the SiO x , forming a mixture, SiO x It is crystalline and / or amorphous, 0.5

[0029] During the process from the beginning of heating to the end of cooling, one or more protective gases such as nitrogen, argon or reducing gas are introduced, and the flow rate is 0.1-0.5m 3 / h.

[0030] The microstructure and shape of the mi...

Embodiment 1

[0043] 1. SiO with a particle size of 1-300 μm 1.0 Carry out heat treatment, pass into high-purity nitrogen protection, the flow rate is 0.2m 3 / h, the heating rate is 1°C / min, the temperature is raised to 1300°C, kept for 6h, and naturally cooled to room temperature. Uniform dispersion of Si particles in SiO x in, because SiO 1.0 Partially differentiated at high temperature to form silicon oxide with x between 1.0 and 2.0, then 1.0figure 1 As shown, Si is in the state of single crystal silicon and polycrystalline silicon of 0.5-50nm, dispersed in SiO x middle.

[0044] 2. Ball milling the mixture to obtain an oxygen-containing silicon-based material with a particle size of 100-300 nm.

[0045] 3. According to the mass percentage, mix and disperse 40% oxygen-containing silicon-based materials, 40% artificial graphite and alcohol to form a slurry evenly, control the solid content of the slurry at 40%, and dry the slurry to obtain a dried product. Then mix and disperse 20% ...

Embodiment 2

[0050] 1. SiO with a particle size of 20-500 μm 0.5 Carry out heat treatment, pass into high-purity nitrogen protection, the flow rate is 0.1m 3 / h, the heating rate is 2°C / min, the temperature is raised to 700°C, kept for 12h, and naturally cooled to room temperature. Uniform dispersion of Si particles in SiO x , forming a mixture, SiO x It is amorphous, 0.5

[0051] 2. Grinding the mixture to obtain an oxygen-containing silicon-based material with a particle size of 50-250 nm.

[0052] 3. According to mass percentage, mix and disperse 85% oxygen-containing silicon-based materials, 5% mesophase carbon microspheres and alcohol to form a slurry evenly, control the solid content of the slurry at 5%, and dry the slurry to obtain dry matter, and then mix and disperse 10% polyacrylonitrile, dry matter and alcohol to form a slurry, control the solid content of the slurry at 45%, and dry the slurry to obtai...

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Abstract

The present invention discloses a lithium-ion battery silicon-carbon anode material and a preparation method thereof, and is to improve specific capacity and cycling performance. The material disclosed by the present invention is composed of an oxygen-containing silicon-carbon composite material and a graphite powder, wherein the oxygen-containing silicon-carbon composite material is formed by dispersing an oxygen-containing silicon-based material in a graphite powder and organic cracking carbon. Comparing the present invention with the prior art, the oxygen-containing silicon-based material is constituted by uniformly dispersing silicon particles in SiOx and a first buffer layer is formed, the oxygen-containing silicon-based material is uniformly dispersed in the organic cracking carbon and the graphite powder to form a second expansion buffer layer, thus the volume expansion effect of the silicon during charging and discharging can be effectively inhibited and cycle stability is improved. The lithium-ion battery silicon-carbon anode material is simple in preparation process, low in raw material costs, and easy for mass production.

Description

technical field [0001] The invention relates to a lithium ion battery material and a preparation method thereof, in particular to a lithium ion battery negative electrode material and a preparation method thereof. Background technique [0002] Lithium-ion batteries have the advantages of high energy density, no memory effect, long service life, green and pollution-free, and small self-discharge. Power stations and other fields, with the development of lithium-ion batteries, it will play a more important role in human production and life. At present, the anode materials of commercialized lithium-ion batteries are mainly graphite materials, but because the theoretical specific capacity is only 372mAh / g, the development potential is limited, and it cannot meet the demand for high energy density of lithium-ion batteries, so the development of anode materials with high specific capacity It has become an urgent need for the lithium-ion battery industry. Among many anode material...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/583H01M4/38H01M4/62
CPCY02E60/10
Inventor 岳敏李胜余德馨黄友元任建国
Owner BTR NEW MATERIAL GRP CO LTD
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