Method for preparing Si/C/graphite composite negative electrode material

A negative electrode material and graphite technology, which is applied in the field of preparation of silicon-based composite materials for lithium-ion batteries, can solve the problems of lithium ion consumption, high cost of nano-silicon, electrode pulverization failure, etc., to improve cycle stability, improve conductivity, The effect of suppressing pulverization failure

Inactive Publication Date: 2014-11-12
广东省工业技术研究院(广州有色金属研究院)
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, if silicon-based anode materials are to be applied to lithium-ion batteries on a large scale, there are mainly the following problems: ①Li + The repeated insertion and extraction of the metal material will lead to repeated distortion and even cracking inside the metal material, which will cause the electrode to pulverize and fail; ② During the first discharge process, an SEI film will be formed at the interface between the active material

Method used

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  • Method for preparing Si/C/graphite composite negative electrode material
  • Method for preparing Si/C/graphite composite negative electrode material
  • Method for preparing Si/C/graphite composite negative electrode material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Weigh 100 g of micron silicon powder with an average particle size of 1.5 μm, and mix them uniformly with 50 g of glucose, then add 500 mL of deionized water, and mill the mixture in a high-energy ball mill for 3 hours to obtain a uniformly dispersed nano-silicon mixture.

[0027] Mix the above mixture with 100g of natural spherical graphite negative electrode material with an average particle size of 12μm, add 500mL of deionized water, and stir for 0.5 hours; adjust the spray drying inlet temperature to 300°C, and the outlet temperature to 120°C, and spray dry to obtain a spherical Particle precursor; under the condition of nitrogen atmosphere and 600°C, the precursor was calcined for 6 hours, cooled to room temperature, and then crushed to obtain Si / C / graphite negative electrode material.

[0028] Using the Si / C / graphite negative electrode material prepared in Example 1, conductive carbon black, and CMC and SBR binders in a mass ratio of 80:10:4:6, deionized water was ...

Embodiment 2

[0031] Weigh 100 g of micron silicon powder with an average particle size of 5 μm and 80 g of sucrose and mix evenly, then add 1000 mL of deionized water, and mill the mixture in a high-energy ball mill for 6 hours to obtain a uniformly dispersed nano-silicon mixture.

[0032] Mix the above mixture with 120g of natural spherical graphite negative electrode material with an average particle size of 20μm, add 200mL of absolute ethanol, and stir for 2 hours; adjust the spray drying inlet temperature to 250°C, and the outlet temperature to 100°C, and spray dry to obtain a spherical Particle precursor; under the condition of nitrogen atmosphere and 800°C, the precursor was calcined for 8 hours, cooled to room temperature, and then crushed to obtain Si / C / graphite negative electrode material.

[0033] The experimental button cell was fabricated in the same manner as in Example 1.

[0034] As shown in Table 1, the experimental button battery made of the material of Example 2 has a spe...

Embodiment 3

[0036] Weigh 100 g of micron silicon powder with an average particle size of 1 μm, and mix them uniformly with 10 g of polyvinyl alcohol, then add 500 mL of absolute ethanol, and mill the mixture in a high-energy ball mill for 2 hours to obtain a uniformly dispersed nano-silicon mixture.

[0037]Mix the above mixture with 100g of natural spherical graphite negative electrode material with an average particle size of 25μm, add 500mL of absolute ethanol, and stir for 2 hours; adjust the spray drying inlet temperature to 350°C, and the outlet temperature to 150°C, and spray dry to obtain spherical graphite Particle precursor; under the condition of nitrogen atmosphere and 800°C, the precursor was calcined for 4 hours, cooled to room temperature, and then crushed to obtain Si / C / graphite negative electrode material.

[0038] The experimental button cell was fabricated in the same manner as in Example 1.

[0039] As shown in Table 1, the experimental button battery made of the mater...

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Abstract

The invention discloses a method for preparing a Si/C/graphite composite negative electrode material. The method for preparing the Si/C/graphite composite negative electrode material comprises the following steps that micron silicon and an organic carbon source are evenly mixed, and deionized water or absolute ethyl alcohol is added to the mixture of the micron silicon and the organic carbon source; ball-milling is conducted on the obtained mixture, so that a nanometer silicon mixture which is evenly dispersed is obtained; a natural spherical graphite negative electrode material is obtained and is evenly mixed with the nanometer silicon mixture, deionized water or absolute ethyl alcohol is added to the mixture of the natural spherical graphite negative electrode material and the nanometer silicon mixture, and stirring is conducted; a mixture is obtained after drying, and a spherical particle precursor is obtained; under the nitrogen condition, the precursor is baked, cooled to the room temperature and then is crushed, and then the Si/C/graphite composite negative electrode material is obtained. According to the method for preparing the Si/C/graphite composite negative electrode material, the micron silicon is taken as the raw material, the Si/C/graphite composite negative electrode material high in cycle performance is prepared, the technology is simple and easy to control, and large-scale production of Si/C/graphite composite negative electrode materials can be achieved easily.

Description

technical field [0001] The invention relates to a method for preparing a silicon-based composite material for a lithium ion battery, in particular to a method for preparing a Si / C / graphite composite material. Background technique [0002] Lithium-ion batteries have the advantages of high energy density, high voltage, long cycle life, no memory effect, safety and pollution-free, etc. They are widely used in portable electronic products such as notebook computers, mobile phones, and digital cameras, and have gradually become an important part of electric vehicles and hybrid electric vehicles. dominant power source. At present, the commercial lithium-ion battery anode materials are artificial graphite and natural graphite, but the theoretical capacity of graphite is only 372mAh / g, which can no longer meet the product's demand for high energy density of lithium-ion batteries. [0003] Since the silicon-based negative electrode material has a high theoretical capacity, which can...

Claims

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Application Information

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IPC IPC(8): H01M4/1393H01M4/62
CPCH01M4/386H01M4/5835H01M10/0525Y02E60/10
Inventor 肖志平肖方明王英唐仁衡孙泰
Owner 广东省工业技术研究院(广州有色金属研究院)
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