(19)
(11)EP 3 533 759 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
24.03.2021 Bulletin 2021/12

(21)Application number: 18791494.0

(22)Date of filing:  10.04.2018
(51)International Patent Classification (IPC): 
C01B 32/19(2017.01)
(86)International application number:
PCT/KR2018/004213
(87)International publication number:
WO 2018/199512 (01.11.2018 Gazette  2018/44)

(54)

GRAPHENE MANUFACTURING METHOD

VERFAHREN ZUR HERSTELLUNG VON GRAPHEN

PROCÉDÉ DE FABRICATION DE GRAPHÈNE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 28.04.2017 KR 20170055639

(43)Date of publication of application:
04.09.2019 Bulletin 2019/36

(73)Proprietor: LG Chem, Ltd.
Seoul 07336 (KR)

(72)Inventors:
  • SON, Jin Young
    Daejeon 34122 (KR)
  • KIM, Cheol Woo
    Daejeon 34122 (KR)
  • AHN, Byoung Hoon
    Daejeon 34122 (KR)
  • CHAE, Hyun Sik
    Daejeon 34122 (KR)
  • CHOY, Sang Hoon
    Daejeon 34122 (KR)

(74)Representative: Hoffmann Eitle 
Patent- und Rechtsanwälte PartmbB Arabellastraße 30
81925 München
81925 München (DE)


(56)References cited: : 
WO-A1-2014/122465
CN-A- 106 587 036
US-A1- 2016 280 551
CA-A1- 2 795 965
KR-A- 20160 048 378
  
  • XIANGLU YIN ET AL: "Preparation of Two-Dimensional Molybdenum Disulfide Nanosheets by High-Gravity Technology", INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, vol. 56, no. 16, 5 April 2017 (2017-04-05) , pages 4736-4742, XP055638678, ISSN: 0888-5885, DOI: 10.1021/acs.iecr.7b00030
  • MIN YI ET AL: "A review on mechanical exfoliation for the scalable production of graphene", JOURNAL OF MATERIALS CHEMISTRY A, vol. 3, no. 22, 1 January 2015 (2015-01-01), pages 11700-11715, XP055323483, GB ISSN: 2050-7488, DOI: 10.1039/C5TA00252D
  • SHEN, SONG ET AL.: 'Preparation of High Quality Graphene Using High Gravity Technology' CHEMICAL ENGINEERING AND PROCESSING vol. 106, 2016, pages 59 - 66, XP029571196
  
Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


Description

Technical Field



[0001] The present invention relates to a method of preparing graphene, wherein the method of preparing graphene may specifically include preparing graphite; and putting the graphite in the inside of a vessel and applying vibration at a frequency of 55 Hz to 65 Hz to the vessel.

BACKGROUND ART



[0002] In general, graphene is a semi-metallic material having a thickness corresponding to a carbon atom layer in which carbon atoms are two-dimensionally arranged in a hexagonal shape and connected by sp2 bonds. The graphene not only has excellent electrical conductivity, but also has structural and chemical stabilities and excellent thermal conductivity. Also, since the graphene is composed of only carbon, a relatively light element, a one-dimensional or two-dimensional nanopattern is easily processed. Above all, the graphene sheet is an inexpensive material, wherein it has excellent price competitiveness in comparison to conventional nanomaterials.

[0003] Due to these electrical, structural, chemical, and economic characteristics, it is predicted that graphene may replace silicon-based semiconductor technology and transparent electrodes in the future, and, particularly, it is expected that graphene may be applied to a flexible electronic device field due to excellent mechanical properties.

[0004] Due to the excellent properties of graphene, various methods capable of more effectively mass-producing graphene from a carbon-based material, such as graphite, have been proposed or studied.

[0005] Among them, a method of preparing graphene by grinding graphite together with a dispersant is used (Korean Patent No. 10-1682007). However, when the above method is used, since the graphene formed during a preparation process is excessively ground due to the dispersant, it is difficult to obtain graphene with desired size and shape, and thus, there is a limitation in that process yield is low and manufacturing cost is high. Also, since type and ratio of the dispersant may be optimally adjusted according to a raw material such as graphite, flexibility of the process may be reduced.

[0006] Therefore, there is a need for a new method of preparing graphene in which a dispersant is not used.

[0007] Patent Document 2 discloses materials and methods for forming a graphene product by vacuum induction heating expandable graphite.

[0008] Non Patent document 3 describes a high-gravity technology to prepare two-dimensional molybdenum disulfide nanosheets from bulk materials.

[Prior Art Document]


[Patent Document]



[0009] 

(Patent Document 1) Korean Patent No. 10-1682007

(Patent Document 2) Canadian Patent application No. 2795965



[0010] (Non Patent document 3) Xianglu Yin, Yuewei Li, Wei Wu, Guangwen Chu, Yong Luo, and Hong Meng, Ind. Eng. Chem. Res. 2017, 56, 4736-4742

DISCLOSURE OF THE INVENTION


TECHNICAL PROBLEM



[0011] An aspect of the present invention provides a method of preparing graphene in which a dispersant is not used and a process is simplified.

TECHNICAL SOLUTION



[0012] According to an aspect of the present invention, there is provided a method of preparing graphene which includes: preparing graphite; and putting the graphite in inside of a vessel and applying vibration at a frequency of 55 Hz to 65 Hz to the vessel, wherein the graphite is the only material included in the vessel to which the vibration is applied, wherein an acceleration of the vibration is in a range of 50 G to 100 G and wherein, the vibration is applied in at least one direction of a vertical direction, a horizontal direction, or a diagonal direction of the vessel.

ADVANTAGEOUS EFFECTS



[0013] According to a method of preparing graphene according to an embodiment of the present invention, since the method does not use a dispersant, a grinding phenomenon of graphene may be prevented, and thus, process yield may be improved and a preparation process may be simplified. Therefore, manufacturing costs may be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS



[0014] The following drawings attached to the specification illustrate preferred examples of the present invention by example, and serve to enable technical concepts of the present invention to be further understood together with detailed description of the invention given below, and therefore the present invention should not be interpreted only with matters in such drawings.

FIG. 1 is a schematic view of a vessel used in a method of preparing graphene of the present invention;

FIG. 2 is an image of graphite used in an embodiment of the present invention;

FIG. 3 is an image of graphene which is prepared by a method of preparing graphene according to an example of the present invention;

FIG. 4 is an image of graphene which is prepared by a method of preparing graphene according to an example of the present invention;

FIG. 5 is an image of graphene which is prepared by a method of preparing graphene according to an example of the present invention;

FIG. 6 is an image of graphene which is prepared by a method of preparing graphene according to a comparative example of the present invention; and

FIG. 7 is an image of graphene which is prepared by a method of preparing graphene according to a comparative example of the present invention.


MODE FOR CARRYING OUT THE INVENTION



[0015] Hereinafter, the present invention will be described in more detail to allow for a clearer understanding of the present invention.

[0016] A method of preparing graphene according to an embodiment of the present invention may include preparing graphite; and putting the graphite in inside of a vessel and applying vibration at a frequency of 55 Hz to 65 Hz to the vessel, wherein the graphite is the only material included in the vessel to which the vibration is applied, wherein an acceleration of the vibration is in a range of 50 G to 100 G and wherein, the vibration is applied in at least one direction of a vertical direction, a horizontal direction, or a diagonal direction of the vessel.

[0017] Since the graphite has a three-dimensional structure in which carbon atom layers are stacked, the graphite may be an arbitrary carbon-based material which may be prepared as graphene having one or more carbon atom layers through exfoliation by an arbitrary physical force such as high speed, high pressure, ultrasonic irradiation, or a shear force.

[0018] In the preparing of the graphene, the graphite may include at least one selected from natural graphite and artificial graphite.

[0019] A shape of the graphite may be any one of an irregular shape, a plate shape, and an expanded shape. Specifically, the shape of the graphite may be a plate shape. In a case in which the shape of the graphite is the plate shape, since the exfoliation of the graphite may be effectively performed by vibration, graphene may be smoothly formed. Thus, graphene having smaller thickness and wider area may be prepared, and, accordingly, graphene with better characteristics and minimized occurrence of defects may be well prepared.

[0020] The graphite may have an average particle diameter (D50) of 5 µm to 30 µm, for example, 5 µm to 20 µm. When the average particle diameter satisfies the above range, a conductive path may be sufficiently secured if the prepared graphene is used in an electrode.

[0021] In the putting of the graphite in the inside of the vessel, the graphite may be added to the inside of the vessel in an amount of 10 vol% to 90 vol%, for example, 50 vol% to 80 vol% based on a total internal volume of the vessel. In a case in which the amount of the graphite added satisfies the above range, the preparation of graphene by collision of graphites may be effectively performed.

[0022] The inside of the vessel may be cylindrical, and, in this case, since a space (dead space), which does not affect the grinding of the graphite, is minimized, process efficiency may be improved.

[0023] The vessel may be a sealed vessel.

[0024] An internal pressure of the vessel to which the graphite is added may be atmospheric pressure. Alternatively, the internal pressure may be 10-2 Hg or less, and may specifically be vacuum. In a case in which the internal pressure of the vessel is 10-2 Hg or less, since collision interference by internal air is somewhat removed, the preparation of the graphene may proceed more smoothly.

[0025] A frequency of the vibration applied to the vessel to which the graphite is added may be in a range of 55 Hz to 65 Hz, for example, 58 Hz to 62 Hz. The graphite is in the form in which a plurality of carbon atom layers are stacked. In the graphite, carbon atoms arranged in the same carbon atom layer are bonded to each other by a double bond, and carbon atoms disposed in different carbon atom layers are bonded to each other by van der Waals bonds that are weaker than the above double bond. Also, the frequency range of 55 Hz to 65 Hz corresponds to a resonance frequency range in which the van der Waals bonds may be broken. Thus, when the vibration within the above frequency range is applied to the graphite, the double bond may be maintained, but the van der Waals bonds may be broken, and thus, graphene may be formed.

[0026] Alternatively, in a case in which vibration outside the above frequency range is applied to the vessel, since the van der Waals bonds are not easily broken, the yield of graphene is decreased.

[0027] A dispersant is not included in the vessel to which the vibration is applied. Specifically, the graphite is the only material included in the vessel to which the vibration is applied. During the preparation of the graphene, since a separate dispersant is not added with the graphite, a process may be simplified. Since it is not necessary to adjust the type and ratio of the dispersant in consideration of raw materials, such as graphite, used in the preparation of the graphene, the process may be flexibly used depending on the purpose of the graphene. Also, since the problem that the prepared graphene is ground by the dispersant may not occur, graphene with the desired size and shape may be obtained smoothly.

[0028] FIG. 1 is a schematic view of the vessel used in the method of preparing graphene of the present invention. Referring to FIG. 1, the vibration may be applied in at least one direction of a vertical direction (a), a horizontal direction (b), and a diagonal direction (c) of a vessel 100 in which graphite 110 is contained. For example, the vibration may be applied only in the vertical direction (a), or may be applied in the horizontal direction (b) or the diagonal direction (c) following the vertical direction (a), and such a pattern may be repeated.

[0029] The vibration may be applied to the vessel for 10 minutes to 60 minutes, for example, 30 minutes to 50 minutes. When the above range is satisfied, graphene may be effectively prepared.

[0030] An acceleration of the vibration is in a range of 50 G to 100 G, for example, 70 G to 80 G. When the above range is satisfied, since the damage to graphite is less, excellent graphene may be prepared.

Examples and Comparative Examples


Example 1: Preparation of Graphene



[0031] Plate-shaped artificial graphite (see FIG. 2) having an average particle diameter (D50) of 10 µm was added to a polycarbonate (PC) vessel having a volume of an internal space of 200 ml, but, in this case, the artificial graphite was added such that an amount of the artificial graphite added was 50 vol% based on a total internal volume of the vessel. Thereafter, the vessel was sealed. Vibration (acceleration: 80 G) at a frequency of 60 Hz was applied to the vessel containing the artificial graphite in a vertical direction for 40 minutes to prepare graphene, and an image of the prepared graphene was taken with a scanning electron microscope (SEM) and presented in FIG. 3.

Example 2: Preparation of Graphene



[0032] Graphene was prepared in the same manner as in Example 1 except that the vibration was applied to the vessel for 60 minutes, and an image of the graphene is presented in FIG. 4.

Example 3: Preparation of Graphene



[0033] Graphene was prepared in the same manner as in Example 1 except that the vibration was applied to the vessel for 10 minutes, and an image of the graphene is presented in FIG. 5.

Comparative Example 1: Preparation of Graphene



[0034] Graphene was prepared in the same manner as in Example 1 except that the frequency of the vibration applied to the vessel was 50 Hz, and an image of the graphene is presented in FIG. 6.

Comparative Example 2: Preparation of Graphene



[0035] Graphene was prepared in the same manner as in Example 1 except that the frequency of the vibration applied to the vessel was 70 Hz, and an image of the graphene is presented in FIG. 7.

[0036] Referring to FIGS. 3 to 7, it may be confirmed that the graphenes prepared by the preparation methods of Examples 1 to 3 had a better thin-film shape than the graphenes prepared by the preparation methods of Comparative Examples 1 and 2. Thus, it may be confirmed that the application of the vibration at a frequency of 55 Hz to 65 Hz is an important factor for preparing high-quality graphene.

[0037] When FIG. 3 and FIG. 5 are compared, it may be understood that the graphene of Example 1 had a more elaborate thin-film shape than the graphene of Example 3. Thus, it may be confirmed that higher-quality graphene may be formed when the time for applying the vibration as well as the frequency was adjusted to an appropriate level.


Claims

1. A method of preparing graphene comprising:

preparing graphite; and

putting the graphite in inside of a vessel and applying vibration at a frequency of 55 Hz to 65 Hz to the vessel, wherein the graphite is the only material included in the vessel to which the vibration is applied, wherein an acceleration of the vibration is in a range of 50 G to 100 G and wherein, the vibration is applied in at least one direction of a vertical direction, a horizontal direction, or a diagonal direction of the vessel.


 
2. The method of claim 1, wherein the graphite has an average particle diameter (D50) of 5 µm to 30 µm.
 
3. The method of claim 1, wherein the graphite comprises at least one of natural graphite or artificial graphite.
 
4. The method of claim 1, wherein a shape of the graphite is any one of an irregular shape, a plate shape, or an expanded shape.
 
5. The method of claim 1, wherein the putting the graphite in the inside of the vessel comprises:
adding the graphite to the inside of the vessel in an amount of 10 vol% to 90 vol% based on a total internal volume of the vessel.
 
6. The method of claim 1, wherein the vibration is applied for 10 minutes to 60 minutes.
 
7. The method of claim 1, wherein the inside of the vessel is cylindrical.
 


Ansprüche

1. Verfahren zur Herstellung von Graphen, umfassend:

Graphit wird hergestellt; und

das Graphit wird in das Innere eines Behälters gegeben und der Behälter wird einer Vibration bei einer Frequenz von 55 Hz bis 65 Hz ausgesetzt, wobei das Graphit das einzige Material ist, das in dem Behälter, welcher der Vibration ausgesetzt ist, eingeschlossen ist, wobei eine Beschleunigung der Vibration in einem Bereich von 50 G bis 100 G liegt und wobei die Vibration in mindestens einer Richtung aus einer vertikalen Richtung, einer horizontalen Richtung oder einer diagonalen Richtung des Behälters angelegt wird.


 
2. Verfahren nach Anspruch 1, wobei das Graphit einen mittleren Teilchendurchmesser (D50) von 5 µm bis 30 µm aufweist.
 
3. Verfahren nach Anspruch 1, wobei das Graphit mindestens eines aus natürlichem Graphit oder künstlichem Graphit umfasst.
 
4. Verfahren nach Anspruch 1, wobei eine Form des Graphits mindestens eine ist aus einer unregelmäßigen Form, einer Plattenform oder einer expandierten Form.
 
5. Verfahren nach Anspruch 1, wobei das Geben des Graphits in das Innere des Behälters folgendes umfasst:
das Graphit wird zum dem Inneren des Behälters in einer Menge von 10 Vol.-% bis 90 Vol.-%, bezogen auf ein gesamtes inneres Volumen des Behälters, hinzugefügt.
 
6. Verfahren nach Anspruch 1, wobei die Vibration für 10 Minuten bis 60 Minuten angelegt wird.
 
7. Verfahren nach Anspruch 1, wobei das Innere des Behälters zylindrisch ist.
 


Revendications

1. Procédé de préparation de graphène comprenant :

la préparation de graphite ; et

la mise en place du graphite à l'intérieur d'un récipient et l'application d'une vibration à une fréquence de 55 Hz à 65 Hz au récipient, dans lequel le graphite est le seul matériau inclus dans le récipient auquel la vibration est appliquée, dans lequel une accélération de la vibration est dans une plage de 50 G à 100 G et dans lequel, la vibration est appliquée dans au moins une direction parmi une direction verticale, une direction horizontale, ou une direction diagonale du récipient.


 
2. Procédé selon la revendication 1, dans lequel le graphite présente un diamètre particulaire moyen (D50) de 5 µm à 30 µm.
 
3. Procédé selon la revendication 1, dans lequel le graphite comprend au moins l'un parmi du graphite naturel ou du graphite artificiel.
 
4. Procédé selon la revendication 1, dans lequel une forme du graphite est l'une quelconque parmi une forme irrégulière, une forme de plaque, ou une forme expansée.
 
5. Procédé selon la revendication 1, dans lequel la mise en place du graphite à l'intérieur du récipient comprend :
l'ajout du graphite à l'intérieur du récipient en une quantité de 10 % en volume à 90 % en volume sur la base d'un volume interne total du récipient.
 
6. Procédé selon la revendication 1, dans lequel la vibration est appliquée pendant 10 minutes à 60 minutes.
 
7. Procédé selon la revendication 1, dans lequel l'intérieur du récipient est cylindrique.
 




Drawing

















Cited references

REFERENCES CITED IN THE DESCRIPTION



This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description




Non-patent literature cited in the description