Silicon-carbon negative electrode material and preparation method thereof

A negative electrode material, silicon carbon technology, applied in the field of silicon carbon negative electrode materials and its preparation, can solve the problems of poor cycle stability, severe volume expansion and contraction, low conductivity, etc., to improve conductivity, ensure effective performance, and high production efficiency Effect

Inactive Publication Date: 2020-09-22
SHAANXI COAL & CHEM TECH INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, silicon materials have problems such as poor cycle stability, severe volume expansion and contraction (300%) during charge and discharge, and low conductivity.

Method used

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  • Silicon-carbon negative electrode material and preparation method thereof
  • Silicon-carbon negative electrode material and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] Dissolve a certain amount of polyaniline into N-methylpyrrolidone (NMP) and then add nano-silicon with a particle size of 200nm (polyaniline: silicon mass ratio is 2%:25%) and stir for a certain period of time, and use a rotary evaporator at 70°C Solvent is evaporated to dryness, obtains the nano-silicon material of one deck conductive carbon film on the surface; The nano-silicon material, graphene, spherical graphite, polyvinylpyrrolidone and sodium alginate are according to a certain ratio (27%: 6%: 45: 0.5 :0.5) Add ball milling pot to mill for 120min, wherein the ratio of ball to material is 8:1, the rotating speed is 500rpm, and the solid content is 30%. +25%. The ball-milled product was formulated to have a solid content of 60% for spray drying treatment, the feed flow rate was 15mL / min, and the inlet and outlet temperatures were 150°C and 100°C, respectively, to obtain the first precursor material. The first precursor material and a certain bitumen (10%) were st...

Embodiment 2

[0031]Dissolve a certain amount of polypyrrole in N-methylpyrrolidone (NMP) and then add nano-silicon with a particle size of 80nm (polypyrrole: silicon mass ratio is 4%:30%) and stir for a certain period of time, using a rotary evaporator at 90°C Solvent is evaporated to dryness, obtains the nano-silicon material of one deck conductive carbon film on the surface; The nano-silicon material, graphene, spherical graphite, polyethyleneimine and sodium alginate are according to a certain ratio (34%: 4%: 35: 1:1) into the ball mill tank for 300min, where the ball-to-material ratio is 6:1, the rotation speed is 300rpm, and the solid content is 40%. %+30%. The ball-milled product was formulated to have a solid content of 60% for spray drying treatment, the feed flow rate was 10mL / min, and the inlet and outlet temperatures were 180°C and 60°C, respectively, to obtain the first precursor material. The first precursor material and a certain bitumen (10%) were stirred and uniformly disp...

Embodiment 3

[0033] Dissolve a certain amount of polyacetylene in N-methylpyrrolidone (NMP) and then add nano-silicon with a particle size of 300nm (polyacetylene:silicon mass ratio is 4%:25%) and stir for a certain period of time, and use a rotary evaporator at 120°C Evaporate the solvent to obtain a nano-silicon material whose surface is coated with a conductive carbon film; add the nano-silicon material, graphene, spherical graphite, and polyvinylpyrrolidone to a ball mill according to a certain ratio (29%:4%:30:2) Medium ball milling for 60 minutes, wherein the ball-to-material ratio is 8:1, the rotation speed is 1000rpm, and the solid content is 20%. Here, the proportion of nano-silicon material is equal to the sum of the proportions of polyacetylene and silicon, that is, 28%=3%+25%. The ball milled product was formulated to have a solid content of 60% and spray-dried, the feed flow rate was 6mL / min, and the inlet and outlet temperatures were 200°C and 100°C, respectively, to obtain th...

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Abstract

The invention discloses a silicon-carbon composite negative electrode material and a preparation method thereof. The silicon-carbon negative electrode material comprises a nano-silicon material whichis prepared from nano-silicon and a conductive polymer material and is coated with a conductive carbon film on the surface, and the nano silicon material coated with the conductive carbon film is uniformly distributedin the spherical graphite, on the surface of the spherical graphite and on the surface of the graphene to form a nano silicon/graphite/graphene structure, and two layers of organic carbon sources are uniformly coatedon the nano silicon/graphite/graphene structure to obtain the silicon-carbon negative electrode material. The conductive polymer material and two layers of organic carbon sources are coated on the surface of the nano silicon, so that the conductivity of the silicon is enhanced, and the expansion of the silicon is inhibited; aslurry is subjected to drying and twiceroasting in a short time through three times of spray drying, so that the silicon-carbon negative electrode material which is relatively good in silicon dispersion effect and is uniformly coated withorganic pyrolytic carbon is obtained; the preparation method of the silicon-carbon composite negative electrode material is simple, environment-friendly, rich in used raw materials, low in equipment cost and suitable for industrial production and application.

Description

technical field [0001] The invention relates to the technical field of electrochemistry and lithium-ion battery negative electrode materials, in particular to a silicon-carbon negative electrode material and a preparation method thereof. Background technique [0002] In recent years, lithium-ion batteries have been widely used in cameras, power tools, computers, mobile phones, power batteries and energy storage due to their advantages such as high energy density, high working voltage, and long life. However, with the continuous development of society, especially today's rapid development of the electric vehicle industry, the demand for high-energy-density lithium-ion batteries is imminent, so the development of high-capacity lithium-ion battery anode materials is also particularly important. [0003] At present, the anode materials for commercial lithium-ion batteries are mainly graphite materials, and their theoretical specific capacity is only 372mAh / g, which cannot meet t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/38H01M4/62H01M10/0525C01B32/05C01B33/02
CPCC01B33/02C01B32/05H01M4/366H01M4/386H01M4/625H01M4/628H01M10/0525H01M2004/021H01M2004/027Y02E60/10
Inventor 白杨芝田占元邵乐曹新龙薛孟尧胥鑫
Owner SHAANXI COAL & CHEM TECH INST
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