Control Of Conjugated Carbon Nanostructures For Applications In Energy Storage Devices

Carbon nano-materials are considered as attractive topics among researches that basedon materials study, which include carbon nonotubes, grapnene and so on. In this paper,electrochemical method is applied to explore new structures and assembly that based oncarbon nanotubes, graphene and graphene quantum dots. Defective-carbon nanotubes,graphene nano-sphere were made and their applications in the field of energy storagedevices were studied.1. Electrochemical cyclic voltammetric (CV) scan is applied to induce the partialoxidation and defect formation along carbon nanotubes (CNTs) as active sites. The initialhydrophobic nanotube surface becomes hydrophilic and a ten-time enhancement incapacitance is observed with respect to the pristine CNT sample. Thus, the electrochemicalCV pretreatment can be used as an effective approach to activate the CNT surface for anenhanced electrochemical performance in capacitors, and many other advanced devices.2. Based on defective carbon nanotubes (d-CNTs) arrays, we have demonstrated thecomposites of conducting polymer of polypyrrole and CNTs (PPy/d-CNTs) by the methodof electrochemical deposition. The induced active sites along CNTs allow the pyrrole getinto the inner walls of the CNTs and coating the PPy on both the outer and inner walls ofthe defective CNTs. As a consequence, the highest capacitance of587F g1is achieved.3. For sutding the self-assambly behavior of the graphene quantum dots and theirapplications in the field of energy storage devices, the composite of graphene quantum dotsand carbon nanotubes (GQDs/CNTs) have been successfully made by the method ofelectrochemical deposition. Carbon film-liked structure with nono-pore was found to formon the surface of CNTs after GQDs’s deposition. It was found that supercapacitorsfabricated from GQD/CNT hybrid arrays exhibited a high capacitance of44mF cm-2,representing a more than200%improvement over that of bare CNT electrodes.4. In order to further study the assembling behavior of graphene quantum dots and theinfluence of electrochemical environment, graphene quantum dots (GQDs) was assembledto form graphene nano-sphere. The mechanism and the influences of the reaction conditionswere studied. The application in the field of supercapacitor was also demonstrated.5. To meet the trend of developing flexible devices, an all-in-one single fiber supercapacitor has been fabricated through region-specific reduction of graphene oxide(GO) fiber by laser irradiation. This fiber supercapacitor with mechanical flexibility andhigh performance could be woven into the textile for wearable electronics and beyond.