# US 2022/0044879 A1 · Large-Area Continuous Flexible Free-Standing Electrode And Preparation Method And Use Thereof

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- Number: US 2022/0044879 A1
- Document ID: US20220044879A1
- Status: Published application
- Kind: A1
- Application number: 17/395,243
- Filed: 2021-08-05
- Published: 2022-02-10
- Earliest claimed: 2020-08-07
- Assignees: Beijing University of Chemical Technology
- Applicants: Beijing University of Chemical Technology
- Inventors: Bin Xu; Mingzhi Li
- Web page: https://patentgrep.com/patent/US20220044879A1

## CPC

- H01G 11/42: Powders or particles, e.g. composition thereof
- C01B 32/184: Preparation
- C01B 32/198: Graphene oxide
- H01G 11/24: 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
- H01G 11/32: Carbon-based
- H01G 11/36: Nanostructures, e.g. nanofibres, nanotubes or fullerenes
- H01G 11/86: specially adapted for electrodes (carbonisation or activation of carbon for the manufacture of electrodes H01G11/34)
- C01B 2204/04: Specific amount of layers or specific thickness
- H01G: CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE (selection of specified materials as dielectric H01B3/00; capacitors having potential barriers H10D1/62, H10K10/10)
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}

## Abstract

A method for preparing a large-area continuous flexible free-standing electrode is provided. The method includes: mixing a reduced graphene oxide, porous carbon particles and a solvent, and dispersing the resulting mixture to obtain a mixed slurry; coating the mixed slurry onto a hydrophobic substrate, and drying, to prepare the large-area continuous flexible free-standing electrode.

## Claims

### Claim 1

A method for preparing a large-area continuous flexible free-standing electrode, comprising:
(1) mixing a reduced graphene oxide, porous carbon particles and a solvent, and dispersing the resulting mixture to obtain a mixed slurry, wherein
the reduced graphene oxide has a sheet number of 2 to 6, and a sheet diameter of 1 to 20 μm,
the porous carbon particles have a particle size of 1 to 5 μm,
a mass ratio of the reduced graphene oxide and the porous carbon particles is in the range of (0.05-0.5):1, and
the mixed slurry has a mass volume concentration of 5 to 20 mg/mL; and
(2) coating the mixed slurry obtained in step (1) onto a hydrophobic substrate, and drying, to obtain the large-area continuous flexible free-standing electrode.

### Claim 2 (depends on 1)

The method of claim 1, wherein the porous carbon particles have a specific surface area of 1500 to 4500 m2/g.

### Claim 3 (depends on 1)

The method of claim 1, wherein the reduced graphene oxide in step (1) is obtained by reducing graphene oxide through a high-temperature method or a chemical method.

### Claim 4 (depends on 3)

The method of claim 3, wherein the graphene oxide is prepared by a process which is one or more selected from the group consisting of a modified Hummer's method, Brodie's process, and Staudenmaier's process.

### Claim 5 (depends on 1)

The method of claim 1, wherein the solvent in step (1) is one or more selected from the group consisting of N,N-dimethylformamide, ethanol, methanol, isopropanol, ethylene glycol, N-methylpyrrolidone, and tetrahydrofuran.

### Claim 6 (depends on 1)

The method of claim 1, wherein the dispersing in step (1) comprises stirring and sonicating the resulting mixture in sequence.

### Claim 7 (depends on 1)

The method of claim 1, wherein coating the mixed slurry obtained in step (1) onto a hydrophobic substrate in step (2) is performed by a means which is one or more selected from the group consisting of automatic blade coating, slot extrusion coating, roll coating, air-knife coating, and dip coating.

### Claim 8 (depends on 1)

A large-area continuous flexible free-standing electrode prepared by the method of claim 1, comprising a three-dimensional conductive network structure which is formed by cross-stacking the reduced graphene oxide and the porous carbon particles.

### Claim 9

A device comprising:
a large-area continuous flexible free-standing electrode formed by a method comprising:
(1) mixing a reduced graphene oxide, porous carbon particles and a solvent, and dispersing the resulting mixture to obtain a mixed slurry, wherein
the reduced graphene oxide has a sheet number of 2 to 6, and a sheet diameter of 1 to 20 μm,
the porous carbon particles have a particle size of 1 to 5 μm,
a mass ratio of the reduced graphene oxide and the porous carbon particles is in the range of (0.05-0.5):1, and
the mixed slurry has a mass volume concentration of 5 to 20 mg/mL; and
(2) coating the mixed slurry obtained in step (1) onto a hydrophobic substrate, and drying, to obtain the large-area continuous flexible free-standing electrode;
wherein the large-area continuous flexible free-standing electrode further comprises a three-dimensional conductive network structure which is formed by cross-stacking the reduced graphene oxide and the porous carbon particles.

### Claim 10 (depends on 8)

The device of claim 8, further comprising a supercapacitor including the large-area continuous flexible free-standing electrode.