Synthesis of ordered Ni/NiO nanocables for electrochemical capacitor application

Ordered Ni/NiO nanocables were fabricated by electrochemical deposition with the aid of an anodic aluminum oxide as a template, followed by annealing at high temperature. Their morphology and structure are characterized, and the results show that each nanocable has a Ni nanowire as the inner core and a coarse NiO layer as an outer shell. As electrode materials for pseudo-capacitors, the ordered Ni/NiO nanocables exhibit a specific capacitance of 398 mF cm−2 at 1 mA cm−2 and good cycling stability. The good electrochemical performance can be attributed to the special core-shell nanocable architecture, in which the Ni nanowire core plays the role of the metallic interconnect as well as fast electron transfer, while the thin NiO shell with a large surface area serves as the active materials.