# US 12,759,882 B2 · Synthesis of carbon nano-onions by nanodiamond annealing and functionalization of carbon materials

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- Number: US 12,759,882 B2
- Document ID: US12759882B2
- Status: Granted
- Kind: B2
- Application number: 18/015,242
- Filed: 2020-07-10
- Published: 2023-08-17
- Granted: 2026-10-13
- Earliest claimed: 2020-07-10
- Applicants: Atomiq Inc
- Inventors: Nima Golsharifi; Suguru Frederick Amakubo
- Web page: https://patentgrep.com/patent/US12759882B2

## CPC

- C01B 32/18: Nanoonions; Nanoscrolls; Nanohorns; Nanocones; Nanowalls
- H01G 11/36: Nanostructures, e.g. nanofibres, nanotubes or fullerenes
- C01P 2002/72: by d-values or two theta-values, e.g. as X-ray diagram
- C01P 2002/82: by IR- or Raman-data
- C01P 2004/04: obtained by TEM, STEM, STM or AFM
- C01P 2006/40: Electric properties
- H01G 11/52: Separators
- 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)
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS

## Abstract

Disclosed herein are methods of synthesizing carbon nano-onions, their functionalization methods, and their use as electrode material. More specifically, disclosed are methods of converting nanodiamonds into carbon nano-onions, chemical synthesis of carbon nano-onions from reagents, and functionalization using reagents, reactive gases, and photoexcitation. The use of the synthesized and functionalized carbon nano-onions as an electrode by using them as a composite structure is also disclosed.

## Claims

### Claim 1

A method of forming carbon nano-onions, comprising:
adding a carbon material comprising nanodiamond to a vessel; and
annealing the carbon material in the vessel under vacuum at a pressure of 10−2-10−7 Pa at a temperature of 1500-4000° C. for 1 min to 24 hr.

### Claim 2 (depends on 1)

The method of claim 1, further comprising wrapping the carbon material in a graphitic sheet prior to said annealing.

### Claim 3 (depends on 2)

The method of claim 2, wherein the graphitic sheet has a thickness of up to 0.25 mm.

### Claim 4 (depends on 1)

The method of claim 1, wherein the carbon material comprises nanodiamond, diamondoid, single-crystal diamond, polycrystalline diamond, diamond-like carbon, sintered diamond, amorphous diamond, diamond powder, and doped variants thereof.

### Claim 5 (depends on 4)

The method of claim 4, wherein the at least one carbon material is of natural, artificial, or derivative origin.

### Claim 6 (depends on 1)

The method of claim 1, wherein the vessel contains at least one inert gas.

### Claim 7 (depends on 6)

The method of claim 6, wherein the at least one inert gas comprises nitrogen, carbon dioxide, argon, helium, neon, krypton, xenon, and/or radon.

### Claim 8 (depends on 1)

The method of claim 1, wherein the annealing is at a temperature of is 1500-2000° C.

### Claim 9 (depends on 1)

The method of claim 1, wherein annealing occurs at an average heating rate of 1° C.-50° C. min−1.

### Claim 10 (depends on 1)

The method of claim 1, wherein the vessel comprises a vacuum hot press.

### Claim 11 (depends on 1)

The method of claim 1, wherein the carbon nano-onions have an average diameter of 5.9 nm to 7.6 nm.

### Claim 12

A method of forming carbon nano-onions, comprising:
mixing copper chloride hydrate and calcium carbide in a vessel at a mixing ratio of copper chloride hydrate to calcium carbide between 2:1 to 4:1;
annealing the mixture in the vessel at a temperature of 1-1500° C. for 1 min to 24 hr under vacuum at a pressure of 10−2-10−7 Pa to form a product;
cooling the annealed product to ambient temperature; filtering the annealed product with at least one filtering agent;
rinsing the filtered product with at least one rinsing agent; and
heating the rinsed product at a temperature of 1-200° C. for 1 min to 24 hr.

### Claim 13 (depends on 12)

The method of claim 12, wherein the mixing ratio is between 2.5:1 to 3.5:1.

### Claim 14 (depends on 12)

The method of claim 12, wherein the cooling comprises at least one of natural cooling, running coolants, cooling bath, heatsink, and airflow cooling.

### Claim 15 (depends on 12)

The method of claim 12, wherein the at least one filtering agent comprises ammonia and carbon tetrachloride.

### Claim 16 (depends on 15)

The method of claim 15, wherein a mixing ratio of ammonia to carbon tetrachloride is between 4:1 to 15:1.

### Claim 17 (depends on 12)

The method of claim 12, wherein the at least one rinsing agent comprises hydrochloric acid and de-ionized water.

### Claim 18 (depends on 17)

The method of claim 17, wherein a mixing ratio of hydrochloric acid to de-ionized water is 1:4.