Electrochemical Charging of Ultra-Thin Films of Conducting Polymer Supported Carbon Nanotubes: Application to Supercapacitors

摘要

Modification of multi-walled carbon nanotubes with ultra-thin films of oxocyanoruthenium structures resulted in their improved capacitive characteristics, as evident from increased specific capacitances and energy densities determined using diagnostic charging-discharging electrochemical experiments (involving cyclic voltammetry, galvanostatic and AC impedance methods). The largest specific capacitance (123 F g~(-1)) was found when the oxocyanoruthenium modified carbon nanotubes were further covered or linked with conducting polymer, namely poly(3,4-ethylenedioxythiophene) or PEDOT, structures. Among important issues are high stability of both inorganic and organic components, attractive electrostatic interactions between negatively charged oxocyanoruthenate and positively charged PEDOT, fast redox transitions of oxocyanoruthenium and high dynamics of charge propagation in PEDOT species, as well as ability to improve distribution of charge by mufti-walled carbon nanotubes.