A Novel Linear Supercapacitor Based On Oriented Carbon Nanotubes / Conjugated Polymer Fibers

Supercapacitors represent a new family of electrochemical storage devices with advantages of small volume, high capacitance, long cycle life and environmental friend. Increasing interests have been currently attracted to make flexible and portable devices in the development of supercapacitors, and a key point is to synthesize high performance electrode materials. In this dissertation, highly aligned carbon nanotube/conjugated polymer composite fibers have been synthesized as novel electrode materials and are twisted to produce a new family of wire-shaped supercapacitors with high efficiencies.Spinnable carbon nanotube (CNT) arrays were first synthesized by a typical chemical vapor deposition process, and continuous CNT fibers had been then spun from the array. The CNT fibers were flexible and showed remarkable mechanical and electric properties which could be further improved by chemical and heating post-reatments or nitrogen doping during the synthesis. Conjugated polymers such as polyaniline had been then incorporated into aligned CNTs to produce composite fibers through an easy electrodeposition process. These composite fibers also exhibited excellent electrocatayltic properties besides the high mechanical strength and electrical conductivity. Two composite fibers were twisted to fabricate novel wire-shaped microsupercapacitors with a specific capacitance of249F/g, and the high performance could be maintained after a thousand cycles. These energy storage wires were also lightweight, flexible and strong, and could be further scaled up by well-developed textile technologies compared with the conventional planar structure.