A Porous Perchlorate-Doped Polypyrrole Nanocoating on Nickel Nanotube Arrays for Stable Wide-Potential-Window Supercapacitors.

A bottom-up synthetic strategy is developed to fabricate a highly porous wave-superposed perchlorate-doped polypyrrole nanocoating on nickel nanotube arrays. The delicate nanostructure and the unique surface chemistry synergistically endow the obtained electrode with revealable pseudocapacitance, large operating potential window, and excellent cycling stability, which are highly promising for both asymmetric and symmetric supercapacitors.