Silicon@carbon/MXene ternary composite material for lithium ion battery and preparation method of silicon@carbon/MXene ternary composite material

A technology for lithium-ion batteries and composite materials, applied in the field of silicon@carbon/MXene ternary composite materials for lithium-ion batteries and its preparation, can solve the problems of serious agglomeration of MXene, difficulty in forming a uniformly dispersed composite structure, poor preparation effect, etc. , to achieve high current rate performance improvement, stable cycle performance, and increase the effect of contact reaction area

Active Publication Date: 2020-07-07
BEIJING UNIV OF CHEM TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the currently reported methods for preparing Si / MXene composites are usually simple ultrasonic mixing or vacuum filtration, etc., the MXene agglomeration is serious, it is difficult to form a uniformly dispersed composite structure, and the preparation effect is poor.

Method used

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  • Silicon@carbon/MXene ternary composite material for lithium ion battery and preparation method of silicon@carbon/MXene ternary composite material
  • Silicon@carbon/MXene ternary composite material for lithium ion battery and preparation method of silicon@carbon/MXene ternary composite material
  • Silicon@carbon/MXene ternary composite material for lithium ion battery and preparation method of silicon@carbon/MXene ternary composite material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] (1) Weigh 0.2423g C 4 h 11 NO 3 Dissolve in 200ml deionized water to make 0.01mol / L Tris buffer. Weigh 100 mg of nano-silicon material with a size of about 90 nm and ultrasonically disperse it in Tris buffer, add 100 mg of dopamine hydrochloride, stir for 24 hours, and collect it by centrifugation to obtain Si@polydopamine material, that is, polydopamine-coated silicon material, such as figure 1 shown;

[0032] (2) Re-disperse the Si@polydopamine material in 100ml deionized water, add 25ml MXene dispersion (2mg / ml), stir for 1h and then vacuum filter to obtain the Si@polydopamine / MXene material (mass ratio, Si:MXene =2:1);

[0033] (3) Transfer Si@polydopamine / MXene to a vacuum oven, and vacuum treatment at 60°C for 6 hours, so that the secondary amine groups of polydopamine and the hydroxyl groups on the surface of MXene undergo a crosslinking reaction to form covalent bonds or hydrogen bonds;

[0034] (4) The cross-linked Si@polydopamine / MXene was placed in a tub...

Embodiment 2

[0041] (1) Weigh 0.2423g C 4 h 11 NO 3 Dissolve in 200ml deionized water to make 0.01mol / L Tris buffer. Weigh 100 mg of nano-silicon material with a size of about 90 nm and ultrasonically disperse it in Tris buffer, add 100 mg of dopamine hydrochloride, stir for 24 hours, and collect by centrifugation to obtain Si@polydopamine material;

[0042] (2) Redisperse the Si@polydopamine material in 100ml deionized water, add 100ml MXene dispersion (2mg / ml), stir for 1h and then vacuum filter to obtain the Si@polydopamine / MXene material (mass ratio, Si:MXene =0.5:1);

[0043] (3) Transfer Si@polydopamine / MXene to a vacuum oven, and vacuum treatment at 60°C for 6 hours, so that the secondary amine groups of polydopamine and the hydroxyl groups on the surface of MXene undergo a crosslinking reaction to form covalent bonds or hydrogen bonds;

[0044] (4) The cross-linked Si@polydopamine / MXene was placed in a tube furnace and treated at 600 °C for 2 h under an argon atmosphere to obta...

Embodiment 3

[0048] (1) Weigh 0.2423g C 4 h 11 NO 3 Dissolve in 200ml deionized water to make 0.01mol / L Tris buffer. Weigh 100 mg of nano-silicon material with a size of about 90 nm and ultrasonically disperse it in Tris buffer, add 100 mg of dopamine hydrochloride, stir for 24 hours, and collect by centrifugation to obtain Si@polydopamine material;

[0049] (2) Redisperse the Si@polydopamine material in 100ml of deionized water, add 12.5ml of MXene dispersion (2mg / ml), stir for 1h and then vacuum filter to obtain the Si@polydopamine / MXene material (mass ratio, Si: MXene=4:1);

[0050] (3) Transfer Si@polydopamine / MXene to a vacuum oven, and vacuum treatment at 60°C for 6 hours, so that the secondary amine groups of polydopamine and the hydroxyl groups on the surface of MXene undergo a crosslinking reaction to form covalent bonds or hydrogen bonds;

[0051] (4) The cross-linked Si@polydopamine / MXene was placed in a tube furnace and treated at 600 °C for 2 h under an argon atmosphere to...

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Abstract

The invention relates to the field of lithium ion battery negative electrode materials, and discloses a silicon@carbon/MXene ternary composite material for a lithium ion battery and a preparation method of the silicon@carbon/MXene ternary composite material. The silicon@carbon/MXene ternary composite material is prepared by the following steps: carrying out dopamine hydrochloride self-polymerization reaction on a silicon material on the surface of the silicon material to form a polydopamine layer, carrying out liquid-phase mixing and crosslinking on the polydopamine layer and MXene, and carrying out high-temperature treatment. According to the method, secondary amino of polydopamine on the surface of the silicon material and hydroxyl on the surface of MXene can be subjected to a cross-linking reaction to form a covalent bond or a hydrogen bond, so the agglomeration phenomenon of the silicon material and MXene is inhibited, and the electrochemical performance of the silicon material isimproved; the size of the silicon material is 20-500 nm, the thickness of the carbon coating layer is 3-10 nm, and the mass ratio of silicon to MXene is (0.5-4): 1. The pore volume of the obtained silicon@carbon/MXene ternary composite material is 0.05-0.3 cm<3>/g, and the specific surface area is 60-120 m<2>/g. The silicon@carbon/MXene ternary composite material is used as a negative electrode material of a lithium ion battery, and shows excellent cycle performance and rate capability.

Description

technical field [0001] The invention belongs to the field of negative electrode materials for lithium ion batteries, in particular to a silicon@carbon / MXene ternary composite material for lithium ion batteries and a preparation method thereof Background technique [0002] Lithium-ion battery is a new type of high-energy battery successfully developed in the 20th century. Due to its charging and discharging process, Li + It is embedded or extracted back and forth between the two electrodes, so it is aptly called a "rocking chair battery". Lithium-ion batteries have the advantages of high storage energy density, long service life, no memory effect, and environmental protection. They have received more and more attention and have been widely used in portable electronic devices, electric vehicles, and aerospace. However, the performance of current commercial lithium-ion batteries cannot meet people's demand for high energy and high power density, so electrode materials with hig...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/38H01M4/587H01M4/62H01M10/0525
CPCH01M4/364H01M4/386H01M4/587H01M4/625H01M10/0525H01M2004/027Y02E60/10
Inventor 徐斌张鹏朱奇珍
Owner BEIJING UNIV OF CHEM TECH
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