# US 8,784,764 B2 · Methods for forming activated carbon material for high energy density ultracapacitors

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- Number: US 8,784,764 B2
- Document ID: US8784764B2
- Status: Granted
- Kind: B2
- Application number: 12/335,078
- Filed: 2008-12-15
- Published: 2010-06-17
- Granted: 2014-07-22
- Earliest claimed: 2008-12-15
- Assignees: Corning Incorporated
- Applicants: Kishor Purushottam Gadkaree; Joseph Frank Mach
- Inventors: Kishor Purushottam Gadkaree; Joseph Frank Mach
- Web page: https://patentgrep.com/patent/US8784764B2

## CPC

- H01M 4/133: Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
- C01B 32/30: Active carbon
- C01B 32/318: characterised by the starting materials
- C01B 32/348: Metallic compounds
- H01G 11/34: characterised by carbonisation or activation of carbon
- H01G 11/44: Raw materials therefor, e.g. resins or coal
- H01M 4/583: Carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M 4/00: Electrodes
- H01M 4/02: Electrodes composed of, or comprising, active material
- H01M 4/86: Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M 4/88: Processes of manufacture
- Y02E 60/10: Energy storage using batteries
- Y02E 60/13: Energy storage using capacitors
- Y02E 60/50: Fuel cells
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- 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)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A method for producing an activated carbon material includes forming an aqueous mixture of a natural, non-lignocellulosic carbon precursor and an inorganic compound, heating the mixture in an inert or reducing atmosphere, cooling the heated mixture to form a first carbon material, and removing the inorganic compound to produce an activated carbon material. The activated carbon material is suitable to form improved carbon-based electrodes for use in high energy density devices.

## Claims

### Claim 1

A method for producing an activated carbon material comprising:
forming an aqueous mixture consisting essentially of a natural, non-lignocellulosic carbon precursor selected from the group consisting of wheat flour, corn flour, rice flour and potato flour, and an inorganic compound;
heating the aqueous mixture in an inert or reducing atmosphere to form a first carbon material; and
removing the inorganic compound from the first carbon material to produce a powdered activated carbon material.

### Claim 2 (depends on 1)

A method according to claim 1, wherein the inorganic compound is selected from the group consisting of an alkali hydroxide, alkali chloride, phosphoric acid, calcium chloride and zinc chloride.

### Claim 3 (depends on 1)

A method according to claim 1, wherein the inorganic compound is selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium chloride and potassium chloride.

### Claim 4 (depends on 1)

A method according to claim 1, wherein a weight ratio of inorganic compound to non-lignocellulosic carbon precursor in the aqueous mixture is between about 5:1 and 1:5.

### Claim 5 (depends on 1)

A method according to claim 1, wherein a weight ratio of inorganic compound to non-lignocellulosic carbon precursor in the aqueous mixture is greater than or equal to 1.

### Claim 6 (depends on 1)

A method according to claim 1, further comprising aging the aqueous mixture for an aging time ranging from between about 0.5 to 8 hours prior to the step of heating.

### Claim 7 (depends on 1)

A method according to claim 1, wherein the step of heating comprising heating the mixture at a temperature in the range of about 600° C. to 900° C.

### Claim 8 (depends on 1)

A method according to claim 1, wherein the step of removing the inorganic compound comprises rinsing the first carbon material in a solvent.

### Claim 9 (depends on 8)

A method according to claim 8, wherein the solvent is water.

### Claim 10 (depends on 1)

The method according to claim 1, further comprising grinding the first carbon material after removing the inorganic compound to form the powdered activated carbon material.

### Claim 11

A method for producing a carbon-based electrode comprising:
forming an aqueous mixture consisting essentially of a natural, non-lignocellulosic carbon precursor selected from the group consisting of wheat flour, corn flour, rice flour and potato flour, and an inorganic compound;
heating the aqueous mixture in an inert or reducing atmosphere to form a first carbon material;
removing the inorganic compound from the first carbon material to produce an activated carbon material;
mixing the activated carbon material with at least one of carbon black and PTFE to form an electrode mixture; and
forming a carbon-based electrode from the electrode mixture.

### Claim 12 (depends on 11)

A method according to claim 11, wherein the activated carbon material is dried to form a powder prior to forming the carbon-based electrode.

### Claim 13 (depends on 11)

A method according to claim 11, further comprising incorporating the carbon-based electrode into a high energy density device.

### Claim 14 (depends on 13)

A method according to claim 13, wherein the high energy density device is an ultracapacitor.

### Claim 15 (depends on 14)

A method according to claim 14, wherein the ultracapacitor has a design selected from the group consisting of a jelly roll design, a prismatic design, and a honeycomb design.

### Claim 16

A method for producing an activated carbon material comprising:
heating a natural, non-lignocellulosic carbon precursor selected from the group consisting of wheat flour, corn flour, rice flour and potato flour in an inert or reducing atmosphere to form a first carbon material;
mixing the first carbon material with an inorganic compound to form a mixture that consists essentially of the first carbon material and the inorganic compound;
heating the mixture in an inert or reducing atmosphere to incorporate the inorganic compound into the first carbon material; and
removing the inorganic compound from the first carbon material to produce an activated carbon material.

### Claim 17 (depends on 16)

A method according to claim 16, wherein the mixture comprises an aqueous mixture of the inorganic compound.

### Claim 18 (depends on 17)

A method according to claim 17, further comprising aging the mixture for an aging time ranging from between about 0.5 to 8 hours prior to the step of heating.

### Claim 19 (depends on 16)

A method according to claim 16, wherein the step of heating the mixture comprising heating at a temperature in the range of about 300° C. to 850° C.

### Claim 20

A method for producing a carbon-based electrode comprising:
heating a natural, non-lignocellulosic carbon precursor selected from the group consisting of wheat flour, corn flour, rice flour and potato flour in an inert or reducing atmosphere to form a first carbon material;
mixing the first carbon material with an inorganic compound to form a mixture that consists essentially of the first carbon material and the inorganic compound;
heating the mixture in an inert or reducing atmosphere to incorporate the inorganic compound into the first carbon material;
removing the inorganic compound from the first carbon material to produce an activated carbon material; and
forming a carbon-based electrode from the activated carbon material.

### Claim 21

A method for producing a carbon-based electrode comprising:
heating a natural, non-lignocellulosic carbon precursor selected from the group consisting of wheat flour, corn flour, rice flour and potato flour in an inert or reducing atmosphere to form an intermediate carbon material that consists essentially of the natural, non-lignocellulosic carbon precursor;
heating the intermediate carbon material in an oxidizing atmosphere to produce an activated carbon material powder; and
forming a carbon-based electrode from the activated carbon material powder.