Ultrathin graphene piece, apparatus for preparing ultrathin graphene piece, method for preparing ultrathin graphene piece, capacitor, and method of manufacturing capacitor

Abstract

The problem addressed by the present invention is to provide an apparatus for preparing ultrathin graphene pieces capable of preparing ultrathin graphene pieces in which less than 10 pieces of graphene are overlapped in large quantities, a method for preparing ultrathin graphene pieces capable of preparing the ultrathin graphene pieces with high yield, an ultrathin graphene piece in which less than 10 pieces of graphene are overlapped, a capacitor having high performance by using the ultrathin graphene piece as an electrode, and an efficient method of manufacturing the capacitor. The above-described problem can be solved by using an apparatus 20 for preparing ultrathin graphene pieces, the apparatus comprising: a graphite electrode 21; a counter electrode 22 which is made of graphite, a corrosion resistant alloy, or a precious metal; an electrolytic solution 25 in which one end sides of the two electrodes 21 and 22 are immersed; a container 24 which stores the electrolytic solution 25; and a power source 28 which is connected to the two electrodes 21 and 22 via wirings 26 and 27. The apparatus is also provided with a porous filter 23 so as to cover at least the immersed part of the graphite electrode 21 that is immersed in the electrolytic solution 25.

Description

TECHNICAL FIELD[0001]The present invention relates to an ultrathin graphene piece, an apparatus for preparing ultrathin graphene pieces, a method for preparing ultrathin graphene pieces, a capacitor, and a method of manufacturing capacitor.[0002]In particular, the present invention relates to an apparatus for preparing ultrathin graphene pieces capable of preparing the ultrathin graphene piece, in which graphenes are continuously exfoliated from a graphite electrode and less than 10 pieces of graphene are overlapped, a method for preparing ultrathin graphene pieces, the ultrathin graphene piece in which less than 10 pieces of graphene are overlapped, a capacitor which uses the ultrathin graphene piece, and a method of manufacturing capacitor.BACKGROUND ART[0003]Graphene is an extremely thin sheet which has a thickness of one carbon atom, and has physical properties and characteristics which exceed those of the materials in the related art, such as high intensity, high conductivity, ...

AI Technical Summary

Benefits of technology

[0078]An apparatus for preparing ultrathin graphene pieces of the present invention comprises: a graphite electrode; a counter electrode which is made of graphite, a corrosion resistant alloy, or a precious metal; an electrolytic solution in which one end sides of the two electrodes are immersed; a container which stores the electrolytic solution; and a power source which is connected to the two electrodes via wirings, and a porous filter is provided so as to cover at least the immersed part of the graphite electrode that is immersed in the electrolytic solution. For this reason, the electrolytic solution can flow in and out via pore of the porous filter. However, it is possible to make many thick graphene pieces into the ultrathin graphene piece in which less than 10 pieces of graphene are overlapped by holding the thick graphene piece which is detached from the graphite electrode in the porous filter without allowing the thick graphene piece which is detached from the graphite electrode to flow in and out, and by continuing to bring the thick graphene piece into contact with the graphite electrode.

[0079]In a method for preparing ultrathin graphene pieces of the present invention, the apparatus for preparing ultrathin graphene pieces which is described above is used, the graphite electrode is used as an anode and the counter electrode is used as a cathode, and a voltage is applied between the electrodes. For this reason, the electrolytic solution can flow in and out via pore of the porous filter. However, it is possible to continue to apply a voltage to the thick graphene piece by holding the thick graphene piece which is detached from the graphite electrode in the porous filter without allowing the thick graphene piece which is detached from the graphite electrode to flow in and out, and by continuing to bring the thick graphene piece into contact with the graphene electrode, and to make many thick graphene pieces into the ultrathin graphene piece in which less than 10 pieces of graphene are overlapped. Powder in which a ratio of the ultrathin graphene piece is high can be made.

[0080]In an ultrathin graphene piece of the present invention, less than 10 pieces of graphene are overlapped. For this reason, it is possible to increase a specific surface area per unit mass, and to improve capacitor performance when the ultrathin graphene piece is molded in a plate shape and used as an electrode.

[0081]In the ultrathin graphene piece of the present invention, a hole(s) is formed in the graphene. For this reason, it is possible to further increase a specific surface area per unit mass, to make an activated ultrathin graphene piece in which specific capacitance can be increased when the ultrathin graphene piece is used as a material of the capacitor, and by using this, to improve capacitor performance.

[0082]In the ultrathin graphene piece of the invention, modifying molecules of any of a carbonyl group, a carboxyl group, or a hydroxyl group are not bound to the graphene. For this reason, it is possible to improve activity of a surface of graphene, to make the activated ultrathin graphene piece in which specific capacitance can be increased when the ultrathin graphene piece is used as a material of the capacitor, and by using this, to improve capacitor performance.

[0083]A capacitor of the present invention comprises: two electrodes; and electrolytic solution impregnated layer which is disposed between the electrodes, and the electrode is an electrode which is made by molding powder comprising the ultrathin graphene piece described above in a plate shape. For this reason, it is possible to make a capacitor having high performance.

Problems solved by technology

However, since the CVD method is a high-cost preparing method, the CVD method cannot be used for an industrial application.

In addition, it is necessary to take a long time for an oxidation-reduction process.

Furthermore, there are an environmental problem and a safety problem due to the strong acid or the hydrazine.

The procedure is easier compared to that of the chemical exfoliation method, but there is a problem that productivity is low, and there are an environmental problem and a safety problem.

However, in the electrolytic exfoliation method in the related art, since the exfoliating of graphene is performed in a short period of time, intercalating of ions of the electrolytic solution is not sufficient, exfoliating of the graphene is not sufficient, and many graphenes are overlapped.

For this reason, finally, there is a problem that the thick graphene piece in which 10 or more graphenes are overlapped is collected.

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