Preparation method for graphene aerogel

A graphene aerogel and graphene technology are applied in the preparation of supercapacitor electrode materials and in the field of graphene aerogel preparation, which can solve unstable performance, large differences in graphene aerogel structure, and unstable physical indicators. and other problems, to achieve the effect of low density, stable material performance and stable structure

Inactive Publication Date: 2015-08-19
BEIJING BORGWARD AUTOMOBILE CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] In order to solve the problem that the structure of the graphene airgel prepared by the hydrothermal method is relatively large and the physical index is unstable, resulting in unstable performance when it is used as an electrode material, and then provide a stable structure, uniform Preparation method of graphene airgel with good properties

Method used

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  • Preparation method for graphene aerogel
  • Preparation method for graphene aerogel
  • Preparation method for graphene aerogel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] (1) Dissolve polyvinyl alcohol (PVA) in distilled water, ultrasonically disperse, and prepare 2.5mg / cm 3 Aqueous solution of polyvinyl alcohol;

[0028] (2) ultrasonically disperse the solid graphene oxide in the polyvinyl alcohol aqueous solution prepared in step (1), and prepare a concentration of 1 mg / cm 3 Graphene oxide dispersion;

[0029] (3) Take 20cm 3 The graphene oxide dispersion is subjected to liquid nitrogen freezing to obtain a frozen sample;

[0030] (4) Put the frozen sample into a freeze dryer and freeze dry it for 2 days;

[0031] (5) Put the freeze-dried sample into a porcelain cup and then put it into a vacuum drying furnace. Under the protection of a mixed gas formed by argon and hydrogen (the volume of hydrogen accounts for 5% of the volume of the mixed gas), high-temperature reduction is carried out. The temperature was controlled at 350°C for drying and heating for 3 hours, and then it was reduced at 900°C for 3 hours and cooled naturally, wh...

Embodiment 2

[0033] (1) Dissolve polyvinyl alcohol (PVA) in distilled water, ultrasonically disperse, and prepare 2.5mg / cm 3 Aqueous solution of polyvinyl alcohol;

[0034] (2) ultrasonically disperse the solid graphene oxide in the polyvinyl alcohol aqueous solution prepared in step (1), and prepare a concentration of 5 mg / cm 3 Graphene oxide dispersion;

[0035] (3) Take 20cm 3 The graphene oxide dispersion is subjected to liquid nitrogen freezing to obtain a frozen sample;

[0036] (4) Put the frozen sample into a freeze dryer and freeze dry it for 2 days;

[0037] (5) Put the freeze-dried sample into a porcelain cup and then put it into a vacuum drying furnace. Under the protection of a mixed gas formed by argon and hydrogen (the volume of hydrogen accounts for 5% of the volume of the mixed gas), high-temperature reduction is carried out. The temperature was controlled at 400°C for 3 hours, followed by high-temperature reduction at 1100°C for 3 hours and then cooled naturally, whic...

Embodiment 3

[0039] (1) Dissolve polyvinyl alcohol (PVA) in distilled water, ultrasonically disperse, and prepare 2.5mg / cm 3 Aqueous solution of polyvinyl alcohol;

[0040] (2) ultrasonically disperse the solid graphene oxide in the polyvinyl alcohol aqueous solution prepared in step (1), and prepare a concentration of 8 mg / cm 3 Graphene oxide dispersion;

[0041] (3) Take 20cm 3 The graphene oxide dispersion is subjected to liquid nitrogen freezing to obtain a frozen sample;

[0042] (4) Put the frozen sample into a freeze dryer for freeze-drying for 2 days,

[0043] (5) Put the freeze-dried sample into a porcelain cup and then put it into a vacuum drying furnace. Under the protection of a mixed gas formed by argon and hydrogen (the volume of hydrogen accounts for 5% of the volume of the mixed gas), high-temperature reduction is carried out. The temperature was controlled at 450°C for 2.5 hours, followed by high-temperature reduction at 1000°C for 3 hours and then cooled naturally to ...

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Abstract

The invention discloses a preparation method for graphene aerogel. The method comprises the following steps: preparing an aqueous polyvinyl alcohol solution containing graphene oxide so as to obtain a graphene oxide dispersion liquid with a concentration of 1 to 10 mg / cm<3>; subjecting the graphene oxide dispersion liquid to freezing in the condition of no higher than minus 196 DEG C so as to obtain a frozen sample; subjecting the frozen sample to freezing and drying so as to obtain a frozen-dried sample; and subjecting the frozen-dried sample in an argon-hydrogen mixed gas environment to high-temperature reduction so as to obtain the required graphene aerogel, wherein the high-temperature reduction comprises the steps of burning at 350 to 450 DEG C for 2 to 3 hours and burning again at 900 to 1100 DEG C for 2 to 3 hours. The preparation method for the graphene aerogel provided by the invention adopts a liquid nitrogen freezing manner to obtain a graphene oxide aerogel precursor, the subsequent segmented high-temperature reduction process is combined, the frozen-dried sample undergoes high-temperature burning at different temperatures, polyvinyl alcohol is removed and graphene oxide is reduced at high temperature, so the graphene aerogel is finally obtained; meanwhile, the graphene aerogel obtained by using the method in the invention has stable structure, good homogeneity and stable material performance.

Description

technical field [0001] The invention relates to a preparation method of a supercapacitor electrode material, in particular to a preparation method of a graphene aerogel, and belongs to the technical field of preparation of capacitor electrode materials. Background technique [0002] Traditional capacitors are usually made of a set of conductive plates plus an insulating material in the middle, and the capacitance that can be provided is usually in the order of mF and μF. With the development of science, capacitors with hundreds of thousands of farads have appeared, that is, supercapacitors. Compared with batteries and traditional capacitors, supercapacitors with moderate specific energy are in between and can store energy through fast charging. in the device. In the application of hybrid electric vehicles and pure electric vehicles, supercapacitors can maximize the recovery of energy during braking due to their rapid charging capabilities, and because of their rapid dischar...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B31/04
Inventor 张英涛
Owner BEIJING BORGWARD AUTOMOBILE CO LTD
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