High performance nano/micro composite fiber capable of storing electrical energy and method for fabricating thereof

A method for fabricating a nano/micro composite fiber capable of storing electrical energy, comprising:

• wet spinning an aqueous dispersion of graphene or graphene/carbon nanotube to prepare a microfiber;
• bundling the microfibers to prepare a microfiber bundle;
• heating the microfiber at a temperature between 60° C. and 100° C. under a strong acid to modify the surface of microfibers;
• wrapping the microfiber bundle with a nanofiber web to prepare a nano/micro composite fiber, wherein the nanofiber web is coated with one or more materials selected from the group consisting of metal, carbon nanotube, activated carbon, and metal oxide nanoparticle;
• impregnating the nano/micro composite fiber with an electrolyte to form an electrolyte layer;
• twisting one or more pairs of electrolyte-coated nano/micro composite fibers;
• sheathing the electrolyte-coated nano/micro composite fiber with insulating material.