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 composition comprising a graphene macro-assembly (GMA)-fullerene composite, wherein the GMA-fullerene composite comprises a GMA comprising a three-dimensional network of graphene sheets crosslinked by covalent carbon bonds, and at least 20 wt.% of at least one fullerene compound incorporated into the GMA based on the weight of the GMA.
2. The composition of claim 1 , wherein the fullerene compound is covalently bound to the graphene sheets.
3. The composition of claim 2 , wherein the fullerene compound 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 conjugated linker covalently linking the fullerene to the graphene sheet, and
n is at least one.
4. The composition of claim 3 , wherein the conjugated linker comprises a conjugated C 1 -C 30 hydrocarbon chain optionally substituted with one or more heteroatoms.
5. The composition of claim 4 , wherein the conjugated linker comprises alternating single and multiple bonds, and optionally comprises at least one aromatic or heteroaromatic ring.
6. The composition of claim 4 , wherein n is 1 or 2, F* is C 60 or C 70 , and R 1 is
7. The composition of claim 1 , wherein the fullerene compound is noncovalently attached to the graphene sheets.
8. The composition of claim 7 , wherein the fullerene compound comprises at least one phenylamine functionlized fullerene.
9. The composition of claim 8 , 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.
10. The composition of claim 9 , wherein the conjugated linker comprises a conjugated C 1 -C 30 hydrocarbon chain optionally substituted with one or more heteroatoms.
11. The composition of claim 9 , wherein the conjugated linker comprises alternating single and multiple bonds, and optionally comprises at least one aromatic or heteroaromatic ring.
12. The composition of claim 9 , wherein n is 1 or 2, F* is C 60 or C 70 , and R 2 is
13. The composition of claim 1 , wherein the GMA-fullerene composite comprises at least 50 wt.% of the fullerene compound based on the weight of the GMA.
14. The composition of claim 1 , wherein the GMA-fullerene composite comprises at least 100 wt.% of the fullerene compound based on the weight of the GMA.
15. The composition of claim 1 , wherein the GMA-fullerene composite is a monolith having a thickness of at least 1 mm.
16. The composition of claim 1 , wherein the GMA-fullerene composite has an electrical conductivity of at least 10 S/m.
17. The composition of claim 1 , wherein the GMA-fullerene composite has a mesopore volume of at least 0.5 cm 3 /g.
18. The composition of claim 1 , wherein the GMA-fullerene composite has a BET surface area of at least 200 m 2 /g.
19. The composition of claim 1 , wherein the GMA-fullerene composite has a Young's modulus of at least 20 MPa.
20. A supercapacitor comprising an electrode comprising the GMA-fullerene composite of claim 1 , and further comprising an organic or ionic liquid electrolyte in contact with the electrode.