Capacitor electrode material, method for producing same, and electric double layer capacitor

Patent metadata

Field	Value
Publication number	US-10658126-B2
Application number	US-201414914618-A
Country	US
Kind code	B2
Filing date	Dec 19, 2014
Priority date	Dec 26, 2013
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

There is provided a capacitor electrode material that does not require the use of a conductive aid and can increase the capacitance of an electric double layer capacitor. A capacitor electrode material comprising resin-remaining partially exfoliated graphite obtained by pyrolyzing a resin in a composition in which the resin is fixed to graphite or primary exfoliated graphite by grafting or adsorption, the resin-remaining partially exfoliated graphite having a structure in which graphite is partially exfoliated, with part of the resin remaining; and a binder resin.

First claim

The invention claimed is:

1. A capacitor electrode material comprising
resin-remaining partially exfoliated graphite obtained by pyrolyzing a resin in a composition in which the resin is previously fixed to graphite or primary exfoliated graphite by grafting or adsorption, the resin-remaining partially exfoliated graphite having a structure in which graphite is partially exfoliated, with part of the resin remaining; and
a binder resin,
wherein when an amount of methylene blue adsorbed per g of the resin-remaining partially exfoliated graphite (μmol/g) is y, the amount of methylene blue adsorbed being measured based on a difference between an absorbance of a methanol solution of methylene blue at a concentration of 10 mg/L and an absorbance of a supernatant liquid obtained by introducing the resin-remaining partially exfoliated graphite into the methanol solution of methylene blue followed by centrifugation, and a BET specific surface area (m 2 /g) of the resin-remaining partially exfoliated graphite is x, a ratio y/x is 0.15 or more, and the BET specific surface area of the resin-remaining partially exfoliated graphite is 40 m 2 /g or more.

2. The capacitor electrode material according to claim 1 , wherein a pyrolysis initiation temperature and a pyrolysis end temperature of the remaining resin in the resin-remaining partially exfoliated graphite are higher than a pyrolysis initiation temperature and a pyrolysis end temperature of the resin before the pyrolysis, respectively.

3. The capacitor electrode material according to claim 1 , wherein the resin is at least one resin selected from a group consisting of polyglycidyl methacrylate, polypropylene glycol, polyvinyl acetate, polybutyral, and polyacrylic acid.

4. The capacitor electrode material according to claim 1 , wherein the binder resin is polybutyral, polytetrafluoroethylene, or a fluorine-based polymer.

5. The capacitor electrode material according to claim 4 , wherein the fluorine-based polymer is polyvinylidene fluoride.

6. The capacitor electrode material according to claim 1 , comprising 0.3 to 40 parts by weight of the binder resin based on 100 parts by weight of the resin-remaining partially exfoliated graphite.

7. A method for producing a capacitor electrode material, comprising steps of:
pyrolyzing a resin in a composition in which the resin is previously fixed to graphite or primary exfoliated graphite by grafting or adsorption to obtain resin-remaining partially exfoliated graphite which has a structure in which graphite is partially exfoliated and in which part of the resin remains; and
incorporating a binder resin in the resin-remaining partially exfoliated graphite followed by forming into a capacitor electrode material.

8. The method for producing a capacitor electrode material according to claim 7 , wherein the forming of the capacitor electrode material is performed by sheeting by a rolling roller followed by drying.

9. An electric double layer capacitor comprising the capacitor electrode material according to claim 1 .

10. A capacitor electrode material comprising
resin-remaining partially exfoliated graphite obtained by pyrolyzing a resin in a composition in which the resin is previously fixed to graphite or primary exfoliated graphite by grafting or adsorption, the resin-remaining partially exfoliated graphite having a structure in which graphite is partially exfoliated, with part of the resin remaining; and
a binder resin,
wherein the resin-remaining partially exfoliated graphite has a central portion having a graphite structure and an edge portion having an exfoliated structure, and a BET specific surface area of the resin-remaining partially exfoliated graphite is 40 m 2 /g or more.

Assignees

• Sekisui Chemical Co Ltd
• Univ Oita

Inventors

• Fujiwara Akihiko
• Nozato Shoji
• Nakasuga Akira
• Hyodo Shunji
• Yoshitani Hiroshi
• Toyoda Masahiro

Classifications

• H01G11/34

  characterised by carbonisation or activation of carbon · CPC title

• H01G11/38 Primary

  Carbon pastes or blends; Binders or additives therein · CPC title

• H01G11/86

  specially adapted for electrodes (carbonisation or activation of carbon for the manufacture of electrodes H01G11/34) · CPC title

• Y02E60/13

  Energy storage using capacitors · CPC title

• H01G11/44

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