Secondary battery, graphene oxide, and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-10944110-B2
Application number	US-201916454116-A
Country	US
Kind code	B2
Filing date	Jun 27, 2019
Priority date	Dec 24, 2015
Publication date	Mar 9, 2021
Grant date	Mar 9, 2021

Abstract

To provide a manufacturing method of graphene oxide that allows mass production through a relatively simple process, at low costs, and with safety and efficiency. A hydrogen peroxide solution, sulfuric acid, and flake graphite are put in a reaction container, and the mixture is stirred to obtain expansion graphite. The synthesized expansion graphite is washed not with pure water but with a saturated aqueous solution of magnesium sulfate (MgSO 4 ) or an organic solvent, whereby a large amount of sulfuric acid is contained between graphite layers. The expansion graphite is subjected to heat treatment or microwave irradiation to form expanded graphite, and a graphite layer is peeled by ultrasonic treatment and then oxidized to form a graphene compound.

First claim

What is claimed is:

1. A method for manufacturing a graphene compound, comprising the steps of:
inserting sulfuric acid between layers of graphite;
washing the graphite with an aqueous solution containing sulfate or an organic solvent after the step of inserting; and
oxidizing the graphite after the step of washing.

2. The method for manufacturing a graphene compound according to claim 1 , wherein the sulfate is magnesium sulfate, potassium sulfate, or titanium sulfate.

3. The method for manufacturing a graphene compound according to claim 1 , wherein the graphite is flake graphite.

4. The method for manufacturing a graphene compound according to claim 1 , wherein the aqueous solution containing sulfate is a saturated aqueous solution of magnesium sulfate, a saturated aqueous solution of potassium sulfate, or a saturated aqueous solution of titanium sulfate.

5. The method for manufacturing a graphene compound according to claim 1 , wherein the organic solvent is γ-butyrolactone.

6. A method for manufacturing a graphene compound, comprising the steps of:
inserting sulfuric acid between layers of graphite;
washing the graphite with an aqueous solution containing sulfate or an organic solvent after the step of inserting;
forming an expanded graphite from the graphite after the step of washing;
forming a peeled graphite layer from the expanded graphite; and
oxidizing the peeled graphite layer.

7. The method for manufacturing a graphene compound according to claim 6 , wherein the expanded graphite is formed by heat treatment or microwave irradiation.

8. The method for manufacturing a graphene compound according to claim 6 , wherein the peeled graphite layer is formed by ultrasonic treatment, heating treatment, or mechanical peeling.

9. The method for manufacturing a graphene compound according to claim 6 , wherein the sulfate is magnesium sulfate, potassium sulfate, or titanium sulfate.

10. The method for manufacturing a graphene compound according to claim 6 , wherein the graphite is flake graphite.

11. The method for manufacturing a graphene compound according to claim 6 , wherein the aqueous solution containing sulfate is a saturated aqueous solution of magnesium sulfate, a saturated aqueous solution of potassium sulfate, or a saturated aqueous solution of titanium sulfate.

12. The method for manufacturing a graphene compound according to claim 6 , wherein the organic solvent is γ-butyrolactone.

13. A method for manufacturing a graphene compound, comprising the steps of:
inserting sulfuric acid between layers of graphite;
washing the graphite with an aqueous solution containing sulfate or an organic solvent after the step of inserting;
forming an expanded graphite from the graphite after the step of washing;
oxidizing the expanded graphite; and
forming a peeled graphite layer.

14. The method for manufacturing a graphene compound according to claim 13 , wherein the expanded graphite is formed by heat treatment or microwave irradiation.

15. The method for manufacturing a graphene compound according to claim 13 , wherein the peeled graphite layer is formed by ultrasonic treatment, heating treatment, or mechanical peeling.

16. The method for manufacturing a graphene compound according to claim 13 , wherein the sulfate is magnesium sulfate, potassium sulfate, or titanium sulfate.

17. The method for manufacturing a graphene compound according to claim 13 , wherein the graphite is flake graphite.

18. The method for manufacturing a graphene compound according to claim 13 , wherein the aqueous solution containing sulfate is a saturated aqueous solution of magnesium sulfate, a saturated aqueous solution of potassium sulfate, or a saturated aqueous solution of titanium sulfate.

19. The method for manufacturing a graphene compound according to claim 13 , wherein the organic solvent is γ-butyrolactone.

Assignees

• Semiconductor Energy Lab

Inventors

• Yoneda Yumiko
• Oguni Teppei
• Miwa Takuya
• Yamakaji Masaki
• TSURUTA Ayae

Classifications

• H01M50/429

  Natural polymers · CPC title

• H01M50/417

  Polyolefins · CPC title

• H01M4/133

  Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M10/0587

  of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators · CPC title