A novel type of composite electrode based on multiwalled carbon nanotubes (MWNTs)
coated with polypyrrole (PPy) has been used in supercapacitors. A homogeneous layer of
PPy has been deposited on the nanotubular materials by electrochemical polymerization of
pyrrole, that in all cases enhances the specific capacitance. A maximum value of 163 F/g
has been obtained for MWNTs prepared at 600° C and modified by a PPy layer of 5 nm,
whereas it is only 50 F/g for the pristine nanotubes. The open entangled network of the …