Three-dimensional hierarchical porous carbon foams for supercapacitors

Patent metadata

Field	Value
Publication number	US-10850983-B2
Application number	US-201916702997-A
Country	US
Kind code	B2
Filing date	Dec 4, 2019
Priority date	Mar 16, 2016
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

A method of fabricating porous carbon foam includes mixing equal masses of SiO2 particle dispersion with a chitosan solution, dropwise adding a glutaraldehyde aqueous solution into the mixture and solidifying it in air forming a room temperature hydrogel, lyophilizing the hydrogel to form a sponge-like SiO2-embedded aerogel, carbonizing in a furnace the aerogel to form a SiO2-embedded carbon foam, soaking the embedded carbon foam in NaOH to dissolve the SiO2 particles to form a carbon foam having carbon sheets with sub-micron cavities, immersing the carbon sheets in de-ionized water to remove any NaOH residuals followed by drying, placing the carbon foam in KOH solution followed by drying, annealing in nitrogen atmosphere the dried carbon foam to synthesize a carbon foam with a multi-dimensional porous system, immersing the synthesized carbon foam in de-ionized water to prevent self-burning in air, and rinsing the carbon foam in HCl and water, then oven drying.

First claim

What is claimed:

1. A method of fabricating three-dimensional porous carbon foam for supercapacitors, batteries, catalysts or fuel cells, wherein the method comprising;
a) mixing a SiO 2 particle dispersion with a chitosan solution;
b) adding a glutaraldehyde aqueous solution into the mixture of SiO 2 particle dispersion and chitosan and solidifying in air to form a hydrogel;
c) lyophilizing the hydrogel;
d) carbonizing the hydrogel; and
e) dissolving SiO 2 from the hydrogel to form the three-dimensional porous carbon foam.

2. The method as set forth in claim 1 , wherein three-dimensional porous carbon foam has pore sizes in a range from sub-nm to tens of μm.

3. The method as set forth in claim 1 , wherein the three-dimensional porous carbon foam has a Brunauer-Emmett-Teller surface area of 2905 m 2 g −1 .

4. The method as set forth in claim 1 , wherein the SiO 2 particle dispersion is formed using tetraethyl orthosilicate.

5. The method as set forth in claim 1 , wherein the mass of the SiO 2 particle dispersion is equal to the mass of the chitosan polymer.

6. The method as set forth in claim 1 , wherein the dissolving SiO 2 from the hydrogel is dissolved in a basic solution.

7. A three-dimensional porous carbon foam precursor, comprising;
a) a mixture of SiO 2 particles and chitosan; and
b) glutaraldehyde solidified with the mixture of SiO 2 particles and chitosan.

Assignees

• Univ California

Inventors

• Li Yat
• Zhang Feng
• Liu Tianyu

Classifications

• C01B32/00

  Carbon; Compounds thereof (C01B21/00, C01B23/00 take precedence; percarbonates C01B15/10; carbon black C09C1/48) · CPC title

• C01P2006/12

  Surface area · CPC title

• H01G11/44

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

• C01P2004/30

  extending in three dimensions · CPC title

• C01P2004/03

  obtained by SEM · CPC title