Graphene macro-assembly-fullerene composite for electrical energy storage
Disclosed here is a method for producing a graphene macro-assembly (GMA)-fullerene composite, comprising providing a GMA comprising a three-dimensional network of graphene sheets crosslinked by covalent carbon bonds, and incorporating at least 20 wt. % of at least one fullerene compound into the GMA based on the initial weight of the GMA to obtain a GMA-fullerene composite. Also described are a GMA-fullerene composite produced, an electrode comprising the GMA-fullerene composite, and a supercapacitor comprising the electrode and optionally an organic or ionic liquid electrolyte in contact with the electrode.
1. A method for producing a graphene macro-assembly (GMA)-fullerene composite, comprising providing a GMA comprising a three-dimensional network of graphene sheets crosslinked by covalent carbon bonds, and incorporating at least 20 wt. % of at least one fullerene compound into the GMA based on the initial weight of the GMA to obtain the GMA-fullerene composite, wherein the fullerene compound is covalently bound to the graphene sheets.
2. The method of claim 1 , wherein the incorporating step comprises reacting the GMA with least one diazonium functionlized fullerene.
3. The method of claim 2 , wherein the diazonium functionlized fullerene is represented by: F*—(R 1 ) n , wherein:
F* comprises a fullerene having a surface comprising six-membered and five-membered rings,
R 1 comprises a diazonium group and a conjugated linker covalently connecting the diazonium group to the fullerene, and
n is at least one.
4. The method of claim 3 , wherein n is 1 or 2, F* is C 60 or C 70 , and R 1 is selected from the group consisting of
5. The method of claim 1 , wherein based on the initial weight of the GMA at least 50 wt. % of the fullerene compound are incorporated into the GMA.
6. The method of claim 1 , wherein based on the initial weight of the GMA at least 100 wt. % of the fullerene compound are incorporated into the GMA.
7. A method for producing a graphene macro-assembly (GMA)-fullerene composite, comprising providing a GMA comprising a three-dimensional network of graphene sheets crosslinked by covalent carbon bonds, and incorporating at least 20 wt. % of at least one fullerene compound into the GMA based on the initial weight of the GMA to obtain the GMA-fullerene composite, wherein the fullerene compound is noncovalently attached to the graphene sheets, and wherein the incorporating step comprises incubating the GMA in a solution comprising at least one phenylamine functionlized fullerene.
8. The method of claim 7 , wherein the phenylamine functionlized fullerene is represented by: F*—(R 2 ) n , wherein:
F* comprises a fullerene having a surface comprising six-membered and five-membered rings,
R 2 comprises a phenylamine group and a conjugated linker covalently connecting the phenylamine group to the fullerene, and
n is at least one.
9. The method of claim 8 , wherein n is 1 or 2, F* is C 60 or C 70 , and R 2 is selected from the group consisting of
10. A GMA-fullerene composite produced by the method of claim 1 .
11. The GMA-fullerene composite of claim 10 , wherein the GMA-fullerene composite is a monolith having a thickness of at least 1 mm.
12. The GMA-fullerene composite of claim 10 , wherein the GMA-fullerene composite has an electrical conductivity of at least 10 S/m.
13. The GMA-fullerene composite of claim 10 , wherein the GMA-fullerene composite has a mesopore volume of at least 0.5 cm 3 /g.
14. The GMA-fullerene composite of claim 10 , wherein the GMA-fullerene composite has a BET surface area of at least 200 m 2 /g.
15. The GMA-fullerene composite of claim 10 , wherein the GMA-fullerene composite has a Young's modulus of at least 20 MPa.
16. A supercapacitor comprising an electrode comprising the GMA-fullerene composite of claim 10 , and further comprising an organic or ionic liquid electrolyte in contact with the electrode.
17. A GMA-fullerene composite produced by the method of claim 7 .
18. A supercapacitor comprising an electrode comprising the GMA-fullerene composite of claim 17 , and further comprising an organic or ionic liquid electrolyte in contact with the electrode.