Carbonaceous material for electric double layer capacitors and method for producing same

Patent metadata

Field	Value
Publication number	US-10879014-B2
Application number	US-201716349489-A
Country	US
Kind code	B2
Filing date	Nov 13, 2017
Priority date	Nov 15, 2016
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

A carbonaceous material for electric double-layer capacitors that is based on a plant-derived carbon precursor, in which carbonaceous material: a BET specific surface area is 1,900 to 2,500 m2/g; an average pore size is 2.2 to 2.6 nm as determined by a nitrogen adsorption method; a volume of micropores having a pore size of 2 nm or smaller is 0.84 to 1.30 cm3/g as determined by the MP method; a ratio of a volume of micropores having a pore size of 1 to 2 nm with respect to the volume of the micropores having a pore size of 2 nm or smaller is 25 to 50% as determined by the MP method; and a volume of mesopores having a pore size of 2 to 50 nm is 0.16 to 0.4 cm3/g as determined by the BJH method.

First claim

The invention claimed is:

1. A carbonaceous material, which is based on a plant-derived carbon precursor, having
a BET specific surface area of from 1,900 to 2,500 m 2 /g,
an average pore size of from 2.2 to 2.6 nm as determined by a nitrogen adsorption method,
a volume of micropores having a pore size of 2 nm or smaller of from 0.84 to 1.30 cm 3 /g as determined by an MP method,
a ratio of a volume of micropores having a pore size of from 1 to 2 nm with respect to the volume of the micropores having a pore size of 2 nm or smaller of from 25 to 50% as determined by the MP method,
a volume of mesopores having a pore size of 2 to 50 nm of 0.16 to 0.4 cm 3 /g as determined by a BJH method, and
having a tap density of from 0.21 to 0.25 g/cm 3 .

2. The carbonaceous material according to claim 1 , having a total pore volume of from 1.0 to 1.5 cm 3 /g as calculated from a nitrogen adsorption amount at a relative pressure P/P 0 of 0.99 on a nitrogen adsorption-desorption isotherm.

3. The carbonaceous material according to claim 1 , wherein the volume of mesopores having a pore size of 2 to 50 nm is 0.19 to 0.35 cm 3 /g.

4. The carbonaceous material according to claim 1 , wherein the carbon precursor is derived from a coconut shell.

5. A method of producing the carbonaceous material according to claim 1 , the method comprising:
performing carbonization, primary activation with water vapor, washing, and secondary activation with water vapor on the plant-derived carbon precursor to obtain the carbonaceous material,
wherein an elemental potassium content in the carbonaceous material after the washing is 500 ppm or less, and
an elemental iron content in the carbonaceous material after the washing is 200 ppm or less.

6. An electrode, comprising:
the carbonaceous material according to claim 1 .

7. An electric double-layer capacitor, comprising:
the electrode according to claim 2 .

8. The carbonaceous material according to claim 1 , wherein the BET specific surface area is from 1,950 to 2,450 m 2 /g.

9. The carbonaceous material according to claim 1 , wherein the BET specific surface area is from 2,000 to 2,400 m 2 /g.

10. The carbonaceous material according to claim 1 , wherein the average pore size is from 2.25 to 2.55 nm.

11. The carbonaceous material according to claim 1 , wherein the average pore size is from 2.3 to 2.5 nm.

12. The carbonaceous material according to claim 1 , wherein the volume of micropores having a pore size of 2 nm or smaller is from 0.90 to 1.25 cm 3 /g.

13. The carbonaceous material according to claim 1 , wherein the volume of micropores having a pore size of 2 nm or smaller is from 1.00 to 1.20 cm 3 /g.

14. The carbonaceous material according to claim 1 , wherein the ratio of a volume of micropores having a pore size of from 1 to 2 nm with respect to the volume of the micropores having a pore size of 2 nm or smaller is from 25 to 48%.

15. The carbonaceous material according to claim 1 , wherein the ratio of a volume of micropores having a pore size of from 1 to 2 nm with respect to the volume of the micropores having a pore size of 2 nm or smaller is from 27 to 45%.

16. The carbonaceous material according to claim 1 , wherein the volume of mesopores having a pore size of 2 to 50 nm is 0.18 to 0.38 cm 3 /g.

Assignees

• Kuraray Co

Inventors

• Nishita Yumika
• Nishimura Shushi
• Egawa Yoshifumi
• Otsuka Kiyoto

Classifications

• H01G11/50

  specially adapted for lithium-ion capacitors, e.g. for lithium-doping or for intercalation · CPC title

• H01G11/44

  Raw materials therefor, e.g. resins or coal · CPC title

• H01G11/34 Primary

  characterised by carbonisation or activation of carbon · CPC title

• H01G11/24 Primary

  characterised by structural features of the materials making up or comprised in the electrodes, e.g. form, surface area or porosity; characterised by the structural features of powders or particles used therefor · CPC title

• C01B32/324

  from waste materials, e.g. tyres or spent sulfite pulp liquor · CPC title