Porous graphene, preparation method thereof, and supercapacitor

A porous graphene and graphene technology, applied in graphene, hybrid capacitor electrodes, nano-carbon, etc., can solve the problems of low tap density of graphene, induce electrolyte, limit commercial application, etc., and achieve high-rate charging Discharge performance, beneficial effect of adsorption and desorption

Active Publication Date: 2013-09-18
NINGBO GRAPHENE INNOVATION CENT CO LTD
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Problems solved by technology

At the same time, this type of supercapacitor has the following disadvantages: due to the poor conductivity of commercial activated carbon, and most of the pores are located inside the particles, in the case of high current charge and discharge, the diffusion of ions in the tortuous activated carbon pores is hindered, and the specific capacity drops rapidly. ; The surface of activated carbon contains some oxygen-containing functional groups, and the oxygen-containing functional groups will induce electrolyte
The graphene material is used as a supercapacitor electrode, and both the organic system electrolyte and the ionic liquid electrolyte produce high specific capacity and energy density, but the graphene prepared by this method has a low tap density, which limits its use. Commercial application in the field of energy storage

Method used

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  • Porous graphene, preparation method thereof, and supercapacitor
  • Porous graphene, preparation method thereof, and supercapacitor
  • Porous graphene, preparation method thereof, and supercapacitor

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preparation example Construction

[0034] The present invention also provides a preparation method of the above-mentioned porous graphene, comprising the following steps: A) mixing two or more flake graphites of different sizes, and then oxidizing to obtain pre-oxidized graphite; B) mixing the pre-oxidized graphite After the expansion treatment, graphene is obtained; C) the graphene is mixed with the first activator, and heated at 400°C-800°C for 0.5-4h to make pores for the first time to obtain microporous graphene; D) the After the microporous graphene is treated with mixed acid, mixed with the second activator, and heated at 600° C. to 1000° C. for 5 to 48 hours to form pores for the second time, the porous graphene is obtained.

[0035] The sources of all raw materials in the present invention are not particularly limited, and they can be commercially available.

[0036] In the present invention, two or more flake graphites of different sizes are mixed, wherein the flake graphite is flake graphite well know...

Embodiment 1

[0053] 1.1 Mix flake graphite of 45 μm, 20 μm and 2 μm uniformly according to the mass ratio of 20:1:1 to obtain mixed graphite; take 5 g of mixed graphite, 87.5 ml of concentrated hydrochloric acid and 45 ml of concentrated nitric acid and mix evenly, then slowly add 45 g of potassium chlorate, React in a water bath at 60° C. for 24 hours, wash repeatedly with deionized water until the pH is neutral, and dry to obtain graphite oxide.

[0054] 1.2 The graphite oxide obtained in 1.1 was thermally expanded in a muffle furnace at 800°C for 30s to obtain graphene, which was formulated into a 0.5wt% aqueous solution at 100°C for spray drying to obtain spherical agglomerates of spherical graphene.

[0055] 1.3 Mix the spherical graphene and potassium hydroxide obtained in 1.2 uniformly in a mass ratio of 20:1, heat to 800°C for 0.5h in a tube furnace containing water vapor and nitrogen atmosphere, and obtain microporous graphene .

[0056] 1.4 Mix 5g of the microporous graphene obt...

Embodiment 2

[0066] 2.1 Mix flake graphite of 100 μm, 50 μm, 20 μm and 2 μm uniformly according to the mass ratio of 10:5:2:1 to obtain mixed graphite; take 1.5g of mixed graphite and 70ml of concentrated sulfuric acid and mix evenly, then slowly add 1.5g of nitric acid Potassium was reacted at room temperature for 2 hours, and 9 g of potassium permanganate was added thereto, reacted in a water bath at 40° C. for 6 hours, washed repeatedly with deionized water until the pH value was neutral, and dried to obtain graphite oxide.

[0067] 2.2 The graphite oxide obtained in 2.1 was thermally expanded in a muffle furnace at 1000° C. for 10 seconds to obtain graphene.

[0068] 2.3 Mix the graphene and potassium hydroxide obtained in 2.2 uniformly according to the mass ratio of 10:1, heat to 600 °C for 2 hours in a tube furnace containing water vapor and nitrogen atmosphere, and obtain microporous graphene, which Prepare a 0.8wt% aqueous solution and spray dry at 120°C to obtain spherical micropo...

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Abstract

The invention provides porous graphene, a preparation method of the porous graphene and a supercapacitor. The porous graphene simultaneously has a mesoporous structure and a macropore structure, and the tap density of the porous graphene is 0.3-0.5g / mL. Compared with the existing graphene at high specific surface area, the porous graphene provided by the invention has quite high tap density and simultaneously has the mesoporous structure and the macropore structure; the mesoporous structure and the macropore structure endow the porous graphene with quite high specific surface area; when the porous graphene is used as the material for the supercapacitor, the macropore structure provides a fast migration passage for an electrolyte; meanwhile the size of the mesoporous structure is equivalent to that of an ion in the organic electrolyte to facilitate the fast desorption and absorption of the ion, so that the capacitor has quite good large-multiplying power charge-discharge performance.

Description

technical field [0001] The invention belongs to the technical field of carbon materials, and in particular relates to a porous graphene, a preparation method thereof, and a supercapacitor. Background technique [0002] Electric double-layer supercapacitors mainly use the huge specific surface area of ​​their electrode materials to store electrical energy through physical processes. They have high power density, cleanliness, fast charge and discharge, long cycle life (more than 100,000 times) and safety and reliability. Widely used in electronic products, electric vehicles and other fields. Among them, electric double-layer supercapacitors can be divided into aqueous supercapacitors and organic double-layer supercapacitors according to the electrolyte. [0003] Commercial aqueous supercapacitor electrode materials are mainly activated carbon, and its internal structure is mainly micropores smaller than 2nm, and because its working voltage can only reach about 1V, the energy ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B31/04H01G11/24C01B32/19
CPCY02E60/13
Inventor 周旭峰刘兆平郑超王国华
Owner NINGBO GRAPHENE INNOVATION CENT CO LTD
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