Supercapacitor having an integral 3D graphene-carbon hybrid foam-based electrode

Patent metadata

Field	Value
Publication number	US-9905373-B2
Application number	US-201614998412-A
Country	US
Kind code	B2
Filing date	Jan 4, 2016
Priority date	Jan 4, 2016
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

Provided is a supercapacitor having an anode, a cathode, a porous separator/electrolyte, wherein at least one of electrodes contains an integral 3D graphene-carbon hybrid foam composed of multiple pores and pore walls, wherein the pore walls contain single-layer or few-layer graphene sheets chemically bonded by a carbon material having a carbon material-to-graphene weight ratio from 1/100 to 1/2, wherein the few-layer graphene sheets have 2-10 layers of stacked graphene planes having an inter-plane spacing d 002 from 0.3354 nm to 0.40 nm and the graphene sheets contain a pristine graphene material having essentially zero % of non-carbon elements, or a non-pristine graphene material having 0.01% to 25% by weight of non-carbon elements wherein said non-pristine graphene is selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, doped graphene, chemically functionalized graphene, or a combination thereof.

First claim

We claim:

1. A supercapacitor having an anode, a cathode, a porous separator electronically separating said anode and said cathode, and/or an electrolyte in ionic contact with said anode and said cathode, wherein at least one of said anode and said cathode contains an integral 3D graphene-carbon hybrid foam as an electrode active material that forms electric double layers of charges or redox pairs, wherein said hybrid foam is composed of multiple pores and pore walls, wherein said pore walls contain single-layer or few-layer graphene sheets chemically bonded by a carbon material having a carbon material-to-graphene weight ratio from 1/200 to 1/2, wherein said few-layer graphene sheets have 2-10 layers of stacked graphene planes having an inter-plane spacing d 002 from 0.3354 nm to 0.40 nm as measured by X-ray diffraction and said single-layer or few-layer graphene sheets contain a non-pristine graphene material having 0.001% to 25% by weight of non-carbon elements wherein said non-pristine graphene is selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, doped graphene, chemically functionalized graphene, or a combination thereof, and said pore walls contain a non-pristine graphene material and wherein said foam contains a content of non-carbon elements in the range of 0.01% to 20% by weight and said non-carbon elements include an element selected from oxygen, fluorine, chlorine, bromine, iodine, nitrogen, hydrogen, or boron.

2. The supercapacitor of claim 1 , further comprising an anode current collector in contact with said anode, and/or a cathode current collector in contact with said cathode.

3. The supercapacitor of claim 1 , wherein both said anode and said cathode contain the integral 3D graphene-carbon hybrid foam as an electrode active material.

4. The supercapacitor of claim 1 , wherein said 3D graphene foam has a density from 0.005 to 1.7 g/cm 3 , a specific surface area from 50 to 3,200 m 2 /g, a thermal conductivity of at least 200 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 2,000 S/cm per unit of specific gravity.

5. The supercapacitor of claim 1 , wherein said pore walls contain a pristine graphene and said 3D graphene-carbon hybrid foam has a density from 0.1 to 1.7 g/cm 3 , an average pore size from 2 nm to 50 nm, and a specific surface area from 300 m 2 /g to 3,200 m 2 /g.

6. The supercapacitor of claim 1 , which is in a continuous-length filament, wire, or sheet form having a thickness or diameter from 200 nm to 10 cm.

7. The supercapacitor of claim 1 , wherein said foam has an oxygen content or non-carbon content less than 1% by weight, and said pore walls have an inter-graphene spacing less than 0.35 nm, a thermal conductivity of at least 250 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 2,500 S/cm per unit of specific gravity.

8. The supercapacitor of claim 1 , wherein said foam has an oxygen content or non-carbon content less than 0.01% by weight and said pore walls contain stacked graphene planes having an inter-graphene spacing less than 0.34 nm, a thermal conductivity of at least 300 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 3,000 S/cm per unit of specific gravity.

9. The supercapacitor of claim 1 , wherein said foam has an oxygen content or non-carbon content no greater than 0.01% by weight and said pore walls contain stacked graphene planes having an inter-graphene spacing less than 0.336 nm, a thermal conductivity of at least 350 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 3,500 S/cm per unit of specific gravity.

10. The supercapacitor of claim 1 , wherein said foam has pore walls containing stacked graphene planes having an inter-graphene spacing less than 0.336 nm, a thermal conductivity greater than 400 W/mK per unit of specific gravity, and/or an electrical conductivity greater than 4,000 S/cm per unit of specific gravity.

11. The supercapacitor of claim 1 , wherein the pore walls contain stacked graphene planes having an inter-graphene spacing less than 0.337 nm and a mosaic spread value less than 1.0.

12. The supercapacitor of claim 1 , wherein said pore walls contain a 3D network of interconnected graphene planes.

13. The supercapacitor of claim 1 , wherein said foam has a physical density higher than 0.8 g/cm 3 and a specific surface area greater than 800 m 2 /g.

14. The supercapacitor of claim 1 , wherein said foam has a physical density higher than 1.0 g/cm 3 and a specific surface area greater than 500 m 2 /g.

15. The supercapacitor of claim 1 , wherein said anode active material or cathode active material further contains a redox pair partner material selected from a metal oxide, a conducting polymer, a non-conducting polymer, an organic material, an inorganic material, or a combination thereof, wherein said partner material is combined with said graphene sheets or carbon material in said hybrid foam to form redox pairs for pseudo-capacitance.

16. The supercapacitor of claim 15 , wherein said metal oxide is selected from RuO 2 , IrO 2 , NiO, MnO 2 , VO 2 , V 2 O 5 , V 3 O 8 , TiO 2 , Cr 2 O 3 , Co 2 O 3 , Co 3 O 4 , PbO 2 , Ag 2 O, or a combination thereof.

17. The supercapacitor of claim 1 , wherein said integral 3D graphene-carbon hybrid foam is chemically or physically activated.

18. A supercapacitor having an anode, a cathode, a porous separator electronically separating said anode and said cathode, and/or an electrolyte in ionic contact with said anode and said cathode, wherein at least one of said anode and said cathode contains an integral 3D graphene-carbon hybrid foam as an electrode active material that forms electric double layers of charges or redox pairs, wherein said hybrid foam is composed of multiple pores and pore walls, wherein said pore walls contain single-layer or few-layer graphene sheets chemically bonded by a carbon material having a carbon material-to-graphene weight ratio from 1/200 to 1/2, wherein said few-layer graphene sheets have 2-10 layers of stacked graphene planes having an inter-plane spacing d 002 from 0.3354 nm to 0.40 nm as measured by X-ray diffraction and said single-layer or few-layer graphene sheets contain a pristine graphene material having essentially zero % of non-carbon elements, or a non-pristine graphene material having 0.001% to 25% by weight of non-carbon elements wherein said non-pristine graphene is selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, doped graphene, chemically functionalized graphene, or a combination thereof, wherein said hybrid foam constitutes an electrode active material loading greater than 10 mg/cm 2 , and/or wherein said hybrid foam constitutes an electrode layer having a thickness no less than 200 μm, and/or said anode active material and said cathode active material combined exceeds 30% by weight of said supercapacitor cell.

19. The supercapacitor of claim 18 , wherein said hybrid foam constitutes an electrode active material loading greater than 15 mg/cm 2 , and/or wherein said hybrid foam constitutes an electrode layer having a thickness no less than 300 μm, and/or said anode active material and said cathode active material combined exceeds 40% by weight of said supercapacitor cell.

20. The supercapacitor of claim 18 , wherein said hybr

Assignees

• Nanotek Instruments Inc

Inventors

• Zhamu Aruna
• Jang Bor Z

Classifications

• H01G11/24

  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

• Y02E60/13

  Energy storage using capacitors · CPC title

• H01G11/32 Primary

  Carbon-based · CPC title

• H01G11/36

  Nanostructures, e.g. nanofibres, nanotubes or fullerenes · CPC title

• H01G11/70

  characterised by their structure · CPC title