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 material and its preparation, can solve the problems of difficult long-term storage, easy emulsification, easy agglomeration, etc., and achieve the effects of stable capacity, smooth surface and low energy consumption

Pending Publication Date: 2022-02-01
北京清研华创新能源科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method solves the problem that nano-sized silicon powder is easy to settle, emulsify, and agglomerate in organic solvents, and is difficult to store for a long time, and at the same time avoids the introduction of damaged powder of zirconium beads in the grinding method. Environmentally friendly and low energy consumption, no oxide layer that is difficult to control is coated on the outer layer of silicon particles, and easy to operate; the surface of nano-silicon particles of silicon-carbon anode materials prepared by this method is smooth and has no edges and corners, which avoids the differentiation and shedding of edges and corners during charging and discharging. , so that the capacity of the silicon-carbon anode material is more stable, and it is evenly distributed in the carbon material, and there is no obvious agglomeration phenomenon

Method used

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

[0054] (1) Crushing silicon powder with a particle size of 3-5um with a jet crusher until the particle size D50 is 50nm;

[0055] (2) Add 10 g of crushed nano-silicon powder into 40 g of isopropanol, then add it to a high-speed disperser, and disperse for 5 hours at a speed of 1500 r / min to obtain a silicon dispersion with a solid content of 20%;

[0056] (3) Weigh 1 g of carboxymethyl cellulose and 2 g of starch, slowly add them to the silicon dispersion under stirring conditions, and disperse at a speed of 1800 r / min for 1.5 hours to obtain solution A;

[0057] (4) Stir and evaporate the solution A to dryness, raise the temperature to 550° C. at a temperature rise rate of 5° C. / min under a nitrogen atmosphere, and roast for 3 hours to obtain a silicon precursor;

[0058] (5) Add 4.5g of artificial graphite, 0.7g of pitch and 3.5g of silicon precursor to 35g of deionized water for high-speed mixing, and disperse at a speed of 1500r / min for 3 hours to obtain solution B;

[00...

Embodiment 2

[0061] (1) Crushing silicon powder with a particle size of 3-5um with a jet crusher until the particle size D50 is 80nm;

[0062] (2) Add 10 g of crushed nano-silicon powder into 40 g of ethanol, then add it to a high-speed disperser, and disperse for 3 hours at a speed of 1500 r / min to obtain a silicon dispersion with a solid content of 18%;

[0063] (3) Weigh 1 g of glucose and 2 g of starch, slowly add them into the silicon dispersion under stirring conditions, and disperse at a speed of 1800 r / min for 1.5 hours to obtain solution A;

[0064] (4) Stir and evaporate the solution A to dryness, raise the temperature to 550° C. at a temperature rise rate of 5° C. / min under a nitrogen atmosphere, and roast for 3 hours to obtain a silicon precursor;

[0065] (5) Add 4.5g of artificial graphite, 0.7g of pitch and 3.5g of silicon precursor to 35g of deionized water for high-speed mixing, and disperse at a speed of 1500r / min for 3 hours to obtain solution B;

[0066] (6) The soluti...

Embodiment 3

[0068] (1) Crushing silicon powder with a particle size of 3-5um with a jet crusher until the particle size is 100nm;

[0069] (2) Add 10 g of crushed nano-silicon powder into 40 g of ethanol, and disperse for 6 hours at a speed of 1500 r / min with a high-speed disperser to obtain a silicon dispersion with a solid content of 16%;

[0070] (3) Weigh 1 g of polycondensate and 2 g of starch, slowly add them into the silicon dispersion under stirring conditions, and disperse at a speed of 1800 r / min for 1.5 hours to obtain solution A;

[0071] (4) Stir and evaporate the solution A to dryness, raise the temperature to 550° C. at a temperature rise rate of 5° C. / min under a nitrogen atmosphere, and roast for 3 hours to obtain a silicon precursor;

[0072] (5) Add 4.5g of artificial graphite, 0.7g of pitch and 3.5g of silicon precursor to 35g of deionized water for high-speed mixing, and disperse at a speed of 1500r / min for 3 hours to obtain solution B;

[0073] (6) The solution B wa...

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Abstract

The invention provides a silicon-carbon negative electrode material and a preparation method thereof. The preparation method comprises the following steps: treating silicon powder until the particle size is 50-100 nm by adopting a high-pressure airflow crushing mode or airflow rotating centrifugal force; dispersing the silicon powder into a dispersion solvent A to obtain a silicon dispersion liquid; mixing a carbon source A with the silicon dispersion liquid, and drying and calcining the obtained solution to obtain a silicon precursor; and dispersing graphite, a carbon source B and a silicon precursor in a dispersion solvent B, and drying and calcining the obtained solution to obtain the silicon-carbon negative electrode material. According to the preparation method of the silicon-carbon negative electrode material, micron silicon is crushed in a high-pressure airflow crushing mode or airflow rotating centrifugal force, then carbon coating treatment is performed, a carbon thin layer is controlled to be 3-10 nm, the volume expansion of silicon particles is reduced, meanwhile, the capacity of the material can be improved through the thin carbon layer, and the initial discharge efficiency and the overall specific capacity of the silicon-carbon negative electrode material are effectively improved.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a silicon-carbon negative electrode material and a preparation method thereof. Background technique [0002] In recent years, with the development of electric vehicles and large-scale energy storage technology, the main device for energy storage, that is, the performance of lithium-ion batteries, including comprehensive performance such as capacity, energy, rate, cycle life, safety, and stability, has been proposed. higher demand. In terms of lithium-ion battery anode materials, graphite-based anode materials are currently mainly used. Due to years of technological development, its capacity is already close to the theoretical capacity of 372mAh / g, and the room for further improvement is very limited. On the other hand, silicon has a very high theoretical capacity, as high as 4200mAh / g, and the raw material reserves of silicon are abundant. Thanks to the...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B33/02C01B32/05C01B32/21H01M4/36H01M4/38H01M4/62H01M10/0525
CPCC01B33/02C01B32/05C01B32/21H01M4/386H01M4/366H01M4/625H01M4/628H01M10/0525H01M2004/027H01M2220/20H01M2220/10Y02E60/10
Inventor 孟垂舟陈玉成王俊明
Owner 北京清研华创新能源科技有限公司
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