Graphene aerogels
Graphene aerogels with high conductivity and surface areas including a method for making a graphene aerogel, including the following steps: (1) preparing a reaction mixture comprising a graphene oxide suspension and at least one catalyst; (2) curing the reaction mixture to produce a wet gel; (3) drying the wet gel to produce a dry gel; and (4) pyrolyzing the dry gel to produce a graphene aerogel. Applications include electrical energy storage including batteries and supercapacitors.
1. A method comprising: preparing a reaction mixture comprising a graphene oxide (GO) suspension and at least one catalyst; curing the reaction mixture to produce a wet gel; drying the wet gel to produce a dry gel; and pyrolyzing the dry gel to produce a graphene aerogel.
2. The method of claim 1 , wherein the GO suspension is an aqueous suspension or a suspension in at least one organic solvent.
3. The method of claim 1 , wherein the reaction mixture comprise a GO concentration of 2 mg/cc or more.
4. The method of claim 1 , wherein the reaction mixture comprises resorcinol and formaldehyde.
5. The method of claim 1 , wherein the reaction mixture is free of resorcinol and formaldehyde.
6. The method of claim 1 , wherein the reaction mixture comprises resorcinol and formaldehyde, and wherein the weight/weight ratio of GO/(resorcinol and formaldehyde) is 0.1 or more.
7. The method of claim 1 , wherein the reaction mixture is cured at a temperature of 100° C. or less.
8. The method of claim 1 , wherein the reaction mixture is cured at atmospheric pressure.
9. The method of claim 1 , wherein the step of drying the wet gel comprises solvent exchange.
10. The method of claim 1 , wherein the step of drying the wet gel comprises drying the wet gel with supercritical CO 2 .
11. The method of claim 1 , wherein the step of pyrolyzing the dry gel comprises drying the dry gel in an inert atmosphere at a temperature of 500° C. or higher.
12. The method of claim 1 , further comprising thermally activating the graphene aerogel in an oxidizing atmosphere to produce an activated graphene aerogel.
13. The method of claim 1 , further comprising thermally activating the graphene aerogel in CO 2 to produce an activated graphene aerogel, wherein the reaction mixture comprises an acid catalyst, resorcinol and formaldehyde, and wherein the activated graphene aerogel has a surface area of 2500 m/g or more and a capacity of 200 F/g or more.
14. The method of claim 1 , wherein the reaction mixture comprises a base catalyst and is free of resorcinol and formaldehyde, and wherein without thermal activation the graphene aerogel has a surface area of 1,000 m/g or more and a capacity of 100 F/g or more.