Honeycomb porous silicon/carbon composite material and preparation method thereof

A silicon-carbon composite material, carbon composite material technology, applied in nanotechnology for materials and surface science, electrical components, battery electrodes, etc., can solve problems such as poor conductivity, broken silicon particles, loss of electrical activity, etc. Simple, improve product purity, and avoid the effect of side reactions

Active Publication Date: 2016-09-21
NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, silicon will produce a huge volume change (up to 300%) during the process of lithium intercalation and deintercalation, resulting in the fragmentation and pulverization of silicon particles, loss of electrical activity, and poor cycle stability.
On the other hand, silicon has poor conductivity, and its rate charge and discharge performance is also poor.

Method used

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  • Honeycomb porous silicon/carbon composite material and preparation method thereof
  • Honeycomb porous silicon/carbon composite material and preparation method thereof
  • Honeycomb porous silicon/carbon composite material and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0047]Step (1). Preparation of silica: use Stober method in alcohol phase medium, catalyze tetrabutyl orthosilicate (TEOS) with ammonia water, form monodisperse spherical silica particles through hydrolysis-condensation, and adjust the pH value Control the particle size at 400 nanometers;

[0048] Step (2). Manually mix the above 1g of silicon dioxide and 1g of magnesium powder at room temperature to obtain a mixture of 2g of silicon dioxide and magnesium;

[0049] Step (3). Package the above-mentioned mixture of silicon dioxide and magnesium in a crucible, place it in a tube furnace, control the heating rate to 4°C / min, heat to 700°C, and react at a constant temperature for 4 hours under an argon atmosphere, and then lower it to room temperature , to obtain the reduced crude product.

[0050] Step (4). The reduced crude product was placed in dilute hydrochloric acid with a concentration of 1 mol / L, stirred at room temperature for 4 hours, centrifuged to obtain a solid produc...

Embodiment 2

[0059] Step (1), preparation of silica: use Stober method in alcohol phase medium, catalyze tetrabutyl orthosilicate (TEOS) with ammonia water, form monodisperse spherical silica particles through hydrolysis-condensation, and adjust the pH value Control the particle size at 80 nanometers;

[0060] Step (2), at room temperature, mix the above-mentioned 1g of silicon dioxide with 0.5g of magnesium powder, and manually grind for 5 minutes in a mortar to obtain a mixture of silicon dioxide and magnesium;

[0061] Step (3), the above-mentioned mixture of silicon dioxide and magnesium is packaged in a crucible, placed in a tube furnace and heated to 650°C at a controlled heating rate of 4°C / min, reacted at a constant temperature for 24 hours under a nitrogen atmosphere, and then lowered to normal temperature, The reduced crude product was obtained.

[0062] Step (4), placing the reduced crude product in dilute hydrochloric acid with a concentration of 0.5 mol / L, stirring at room te...

Embodiment 3

[0070] Step (1). Preparation of silica: use Stober method in alcohol phase medium, catalyze tetrabutyl orthosilicate (TEOS) with ammonia water, form monodisperse spherical silica particles through hydrolysis-condensation, and adjust the pH value Control the particle size at 800 nanometers;

[0071] Step (2). Mix 10 g of the above-mentioned silicon dioxide with 15 g of magnesium powder at room temperature, and manually grind for 10 minutes in a mortar to obtain a mixture of silicon dioxide and magnesium;

[0072] Step (3). Package the above-mentioned mixture of silicon dioxide and magnesium in a crucible, place it in a tube furnace, control the heating rate to 1°C / min, heat to 1000°C, react at a constant temperature for 24 hours under an argon atmosphere, and then lower it to room temperature , to obtain the reduced crude product.

[0073] Step (4). The reduced crude product was placed in dilute hydrochloric acid with a concentration of 2 mol / L, stirred at room temperature for...

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Abstract

The invention discloses a honeycomb porous silicon/carbon composite material and a preparation method thereof. The silicon-carbon composite material is of a hybrid structure that nano silicon spheres are distributed in a honeycomb three-dimensional continuous porous carbon matrix. The method comprises the steps of: adopting spherical silicon dioxide nanoparticles as a silicon source and thermosetting difunctional acrylate unsaturated resin as a carbon source; firstly, mixing silicon dioxide and magnesium powder and then carrying out magnesiothermic reduction in an inert atmosphere to form a continuous porous silicon matrix containing the silicon dioxide nanoparticles; pickling a product obtained by reduction by a hydrochloric acid, evenly dispersing the product into a resin monomer for solidifying, and carrying out high-temperature calcination in the inert atmosphere for in situ carbon formation; and finally etching silicon dioxide which does not completely react by a hydrofluoric acid to obtain the honeycomb porous silicon/carbon composite material and applying the honeycomb porous silicon/carbon composite material to a negative electrode material of a lithium-ion battery. Through in-situ polymerization of vinyl thermosetting resin, the cumbersome problem that traditional thermosetting resin needs to utilize a solvent is solved; post-treatment is not needed; the operation is simple and convenient; and the honeycomb porous silicon/carbon composite material is green and environment-friendly.

Description

technical field [0001] The invention belongs to the field of preparation of porous composite materials, and in particular relates to a method for preparing honeycomb three-dimensional continuous porous silicon-carbon composite materials through magnesia thermal reduction. Background technique [0002] With the rapid development of industries such as electric vehicles, the demand for lithium-ion batteries with high energy density and high power density is increasingly urgent. At present, graphite materials are generally used as anode materials for commercial lithium-ion batteries, but the theoretical lithium storage capacity of graphite is only 372mAh / g, and the lithium intercalation potential platform is close to metal lithium, so fast charging or low-temperature charging is prone to lithium precipitation, causing safety hazards. Therefore, it is imminent to develop new high-performance anode materials. The theoretical specific capacity of silicon is as high as 4200mAh / g, a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/38B82Y30/00
CPCB82Y30/00H01M4/386Y02E60/10
Inventor 程亚军左秀霞朱锦
Owner NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI
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