Microstructure and Properties of Aminated Carbon Nanotubes/Graphene Oxide-MnO_2 Composite for Supercapacitor Electrodes

摘要

MWCNTs-NH_2/GO-MnO_2 composites with different feeding ratio are synthesized by a simple soft chemical route in water-isopropyl alcohol. By amination treatment, carbon nanotubes become more dispersed, thinner and more uniform, and more defect structures are found in MWCNTS-NH_2. MWCNT/S-NH2 grows on the surface of graphene. Nano manganese oxide homogeneously coats on the surfaces of carbon nanotubes and graphene Oxide. Specific capacitances of MWCNTs-NH2/GO-MnO_2 composite calculated by galvanostatic charge/discharge curve were 286.33 F/g at current density 1A-g~(-1) when feeding ratio is 1:1:6. With the increase of the content of manganese oxide, Nyquist semicircle of EIS parallel shifts to the right and the slash slope of EIS is gradually flat, indicating that resistance increases. When the feeding ratio is equal to 1:1:15, the resistance reaches the maximum. The phenomenon may ascribe to the agglomerate of manganese oxide, which hinders the diffusion rate of reaction ions and causes the increase of resistance.