Structural supercapacitors

1. A solid polymer electrolyte comprising a polymer and an ion salt, wherein the polymer is an epoxy comprising

a bis-epoxide selected from the group consisting of poly(ethylene glycol) bisglycidyl ether, bisphenol A diglycidyl ether, resorcinol diglycidyl ether, polydimethyl siloxane bisglycidyl ether, and mixtures thereof, and

a cross-linker comprising 4,4′-methylenebiscyclohexaneamine, 3-aminophenyl sulfone, 4-aminophenyl sulfone, 1,2-diaminocyclohexane, tetramethylene diamine, hexamethylene diamine, bis(3-aminopropyl)amine, benzene 1,2-diamine, triethylenetetramine, tris(2-aminoethyl)amine, ethylenediamine, or a mixture thereof; and

wherein the ion salt is a lithium, a magnesium, or an ammonium salt.

2. The solid polymer electrolyte of claim 1 , wherein the bis-epoxide is selected from the group consisting of poly(ethylene glycol) bisglycidyl ether, resorcinol diglycidyl ether, polydimethyl siloxane bisglycidyl ether, bisphenol A diglycidyl ether, and mixtures thereof.

3. The solid polymer electrolyte of claim 1 , wherein the ion salt is the lithium salt.

4. The solid polymer electrolyte of claim 1 , wherein the cross-linker comprises (i) 4,4′-methylenebiscyclohexaneamine and (ii) triethylenetetramine, tris(2-aminoethyl)amine, ethylenediamine, or a mixture thereof.

5. A capacitor comprising a first carbon fiber electrode, a second carbon fiber electrode, a solid polymer electrolyte of claim 1 , and a separator layer, wherein

the separator layer is disposed between the first carbon fiber electrode and second carbon fiber electrode,

the solid polymer electrolyte is disposed between the first carbon fiber electrode and the separator layer, and

the solid polymer electrolyte is disposed between the second carbon fiber electrode and the separator layer.

6. The capacitor of claim 5 , wherein each carbon fiber electrode either is an activated carbon fiber electrode or has carbon nanotubes grown on the side oriented toward the separator.

7. The capacitor of claim 5 , wherein each carbon fiber electrode comprises a current collector layer.

8. The capacitor of claim 7 , wherein the current collector layer contains at least one of copper, aluminum, and silver.

9. The capacitor of claim 5 , wherein the separator layer is a filter paper, a tissue paper, Celgard 2500, or Celgard 3501.

10. The capacitor of claim 5 , wherein the capacitor is at least partially enclosed with a coating.

11. The capacitor of claim 10 , wherein the coating comprises at least one of nylon, polyethylene, polypropylene, polyester, and an epoxy resin.

12. A prepolymer composition comprising:

an ion salt selected from the group consisting of a lithium, a magnesium, and an ammonium salt,

a bis-epoxide selected from the group consisting of poly(ethylene glycol) bisglycidyl ether, bisphenol A diglycidyl ether, resorcinol diglycidyl ether, polydimethyl siloxane bisglycidyl ether, and mixtures thereof,

a cross-linker comprising 4,4′-methylenebiscyclohexaneamine, 3-aminophenyl sulfone, 4-aminophenyl sulfone, 1,2-diaminocyclohexane, tetramethylene diamine, hexamethylene diamine, bis(3-aminopropyl)amine, benzene 1,2-diamine, triethylenetetramine, tris(2-aminoethyl)amine, ethylenediamine, or a mixture thereof; and

a solvent.

13. A method for preparing a capacitor comprising

assembling a stack comprising a first carbon fiber electrode, a second carbon fiber electrode, a prepolymer composition of claim 12 , and a separator layer, wherein the separator layer is disposed between the first carbon fiber electrode and second carbon fiber electrode, and wherein the prepolymer composition is disposed between the first carbon fiber electrode and the separator layer, and the prepolymer composition is disposed between the second carbon fiber electrode and the separator layer;

and compressing the stacks.

14. The method according to claim 13 , wherein compressing the stacks is at a temperature between about 20° C. and about 100° C., at pressures between 0.5 MPa and 4.5 MPa, and at vacuum pressures between 0.5 and 2 atm.

15. The method of claim 13 , wherein the first carbon fiber electrode and the second carbon fiber electrode are soaked in the prepolymer composition prior to assembly of the stack.

16. A method for preparing a solid polymer electrolyte comprising

adding to a composition comprising a solvent, an ion salt selected from the group consisting of a lithium, a magnesium, and an ammonium salt, and a bis-epoxide selected from the group consisting of poly(ethylene glycol) bisglycidyl ether, bisphenol A diglycidyl ether, resorcinol diglycidyl ether, polydimethyl siloxane bisglycidyl ether, and mixtures thereof, a cross-linker comprising 4,4′-methylenebiscyclohexaneamine, 3-aminophenyl sulfone, 4-aminophenyl sulfone, 1,2-diaminocyclohexane, tetramethylene diamine, hexamethylene diamine, bis(3-aminopropyl)amine, benzene 1,2-diamine, triethylenetetramine, tris(2-aminoethyl)amine, ethylenediamine, or a mixture thereof;

and heating the composition.